Chapter IV: Part 4

“Before I answer that question,” said he, “we must have a little discussion on the nature of _peat_; a substance which seems to be very closely allied to coal, and which, there is no doubt, has been produced by the decay and decomposition of vegetable matter. There are different kinds of peat, therefore, according to the different kinds of plants of which it is composed, and the different situations in which the process has been carried on; such as marsh, forest, and marine peat. Some extensive bogs have been caused within the memory of man, by the decay and natural fall of forests, over which the _sphagnum palustre_ and other mosses rapidly spread; agricultural implements and various domestic utensils have been found under them; and we may therefore assume, that as peat appears to be in the act of progressive increase, it belongs to an order of causes still in action. When examined, peat appears to be an entire mass of vegetable _fibres_: towards the surface they are nearly in an unchanged state, but in the middle the peat becomes more compact; and at the bottom of a very deep and ancient bog, they are almost obliterated, the substance being dense and black, and having all the chemical characters of jet. In some instances beds of peat alternate with beds of mud or sand, which must have been deposited in the bottom of lakes, and in these cases they appear something like an incomplete coal formation.

“In a short time,” continued my uncle, “we shall have a better opportunity of studying this curious substance, if your interest in it continues, when we are in Ireland, as that island contains a greater proportion of bog than any country with which we are acquainted.”

“My interest in it, my dear uncle, I replied, is not very likely to fail while I have your kind assistance; but as we are as yet in a coal country, perhaps you will tell us something of the formation or origin of that mineral.”

“There is no possible doubt,” he said, “that the general origin of coal must be referred to the vegetable kingdom; and I began with peat, to show you how masses of vegetable matter may be collected in thick and very extensive beds, ready for whatever process nature may afterwards employ in converting them into coal. Some species of coal are merely fossil wood (or lignite) impregnated with bitumen: the branches, trunks, and roots, though closely pressed together, are scarcely altered in texture, in some places; while in others they gradually lose every vegetable feature, and the substance in colour, lustre, and fracture, resembles pitch. Of this nature is the Bovey coal of Devonshire, and the Surturbrand of Iceland; and I have some specimens of the former, in which the fibres were flexible when I took them out of the pit, though now hard and brittle. From the disposition of those Bovey lignites, which lie in alternate strata with clay and gravel, it has been reasonably inferred that the trees and vegetables of the adjacent mountains were washed down at different periods into a lake; the clay and gravel, of course, sank first to the bottom, and formed the floor; but in time the trees saturated with moisture, and pressed down by an accumulation of other trees, sank also; and were again, perhaps in succeeding ages, covered by successive depositions.

“The common, or cubical coal, as it is called from the shape into which it breaks, does not bear the same obvious marks of vegetable origin in its structure; but where one species of coal can be so clearly demonstrated to be only altered vegetable matter, it would be bad philosophy to ascribe the other species to other causes. In the prodigious beds of coal, however, in Staffordshire, there is no want of vegetable traces; and even in the Newcastle coal the impressions of leaves and branches are frequently found, as well as in the freestone and slate-clay which intervene between its numerous strata. At Kilsyth, in Scotland, a very singular specimen was discovered; a tree standing upright, with its roots resting on a bed of coal, from which they could scarcely be distinguished, and its stem passing into a stratum of sandstone rock. The lower end was completely bituminated, and it burned with a clear flame; yet the upper part, though scarcely altered in the grain or apparent texture of the wood, was converted into sandstone similar to that by which it was enclosed. Round the stem there was a space of about an inch in thickness filled with coal, which renders it probable that the same process that converted the roots into coal acted upwards on the bark. The rock contains innumerable remains of plants; some of which are so perfect that their species have been made out, and no pencil could trace their delicate ramifications with greater nicety.

“In short,” continued my uncle, “it appears more than probable that every species of coal has proceeded from vegetable matter of different kinds, but under different circumstances; and that its chemical change was effected under the pressure of deep water. In one stage of that process it must have been in a soft pulpy state, like the lowest part of a deep peat-bog; for this is the only way that I can account for the impression of leaves, canes, seed-vessels, and shells, which are so commonly found on the external surface of coal.”

My uncle shewed us a beautiful specimen of a fern leaf, where the impression was as perfect as if it had been made with wax.

He then continued, “Sir James Hall thinks that peat may have been converted into coal by heat acting under great compression; and he has actually succeeded in making a substance very like it. When I have more leisure I will describe the ingenious process which he adopted, as well as some other experiments of the same nature, by which this distinguished philosopher discovered the means of fusing limestone, of imitating volcanic lava, and of forming solid sandstone from loose sand.

“But to return to our coals: the chief difference between the various kinds of coal which are applied to economical purposes, arises from the proportion of bitumen they contain. What is called _caking coal_ yields about 40 per cent.; when burning it swells, agglutinates, and emits much smoke and gas, which inflame at a certain temperature. _Cannel_ coal has only 20 per cent. of bitumen, and does not agglutinate or cake. It burns with a bright flame like a candle, from which circumstance it takes its name, cannel being the common pronunciation of candle in the North of England. The third sort I shall mention is called _anthracite_ by mineralogists; but its common name is _blind_ coal, or Kilkenny coal, from a district in Ireland, where there are vast beds of it. It contains little or no bitumen; it neither cakes nor flames, and gives out very little smoke. But as there are several varieties of coal between those principal species, much confusion has taken place in their names.”

_16th._--When Mary and I were in the garden to-day, I observed a very odd appearance on the under surface of some of the leaves of a pear-tree; they appeared thickly set with strange little downy russet-coloured things like spines growing out of the leaf, perpendicular to it, and about a quarter of an inch in length, and very little thicker than a pin, with a protuberance or excrescence at the base.

Mary was amused at my surprise, and told me that they were the habitations of insects. She then took one of these tubes off the leaf, and on giving it a gentle squeeze, a minute caterpillar, with a yellowish body and black head, came out of the lower end; for the head is always downwards. We examined the place from which she had removed it, and I saw that there was a small hollow in the outer skin and pulpy part of the leaf, which had been eaten away by the caterpillar. It moves this little tube or tent from one part of the leaf to the other, and eats no other part than what the tent covers; and when these insects are abundant, Mary says that every leaf is covered with little withered specks, where they have feasted themselves.

The tube in which the caterpillar lives, is composed of silk, spun from its mouth almost as soon as it comes out of the egg, and as it increases in size it enlarges the tube, by slitting it in two, and introducing a strip of new materials. To preserve the perpendicular posture of its tent, this ingenious insect attaches several silken threads from the protuberance at the base to the surface of the leaf; but it has a still more singular device to protect the tent against any violence: it forms a vacuum in the protuberance at the base, which fastens it to the leaf as effectually as if an air-pump had been employed. This vacuum is caused by the insect’s retreating on the least alarm up the tube, which its body so completely fills that the space below is free of air, and the tube is pressed down like the exhausted receiver of an air-pump.

Mary easily convinced me of this when she seized it suddenly while the insect was at the bottom, the silken cords readily gave way, and the tube was detached by a very slight force; but when she touched it gently, giving the insect time to retreat, we found that a much stronger effort was required to loosen it. As if aware of the effect of the admission of air from below, this little philosopher carefully avoids gnawing quite through the leaf; and when he has eaten as deeply as he can venture, he cuts the cords of his tent and pitches it on a fresh part of the surface. When it has attained its perfect state, it becomes a small brown moth.

_17th._-Mary has been trying a grand experiment, which has succeeded so well that mamma must have an account of it.

My uncle determined to remove a valuable jargonelle pear-tree from one wall to another. I forget his reason, but no matter; it was, however, much too late in the season, and the tree sickened, and seemed to be dying. The gardener declared it could not live; but Mary, who had read that trees in such a predicament might be saved by a gentle but continual drip of water being guided to the roots, requested my uncle to let her try the effect of this plan. He is always anxious to encourage useful experiment, and willingly consigned the tree to her prescriptions.

She took two large flower-pots, and, having carefully corked the holes, she suspended one to each end of a stick, which was fastened across the stem of the tree. A piece of cloth-listing or selvage, long enough to reach the ground, was put into each pot, with a stone tied to it to prevent its slipping out; and the other end of the listing was slit into three parts, which were slightly pegged into the ground. She then had the pots filled with water, and the whole of the listing being wetted, each of them acted like a syphon, drawing the water up over the edge of the pot, as my uncle says by capillary action, and conducting it slowly and regularly into the ground. The moisture spread to the roots, and in three days the young leaves began to revive. The pots were filled every morning, and she changed the listing once a week, as the filaments of the cloth became clogged, and the water was not so freely transmitted. The daily improvement of the tree was very gratifying to my uncle, who enjoyed Mary’s ingenuity and success; and even the gardener has this morning pronounced it to be out of danger.

_18th._--I am afraid that my dear mamma will call me a little credulous simpleton when she reads this account of the singular sagacity of a cat; but my aunt took great pains to ascertain that it was quite correct.

Dame Moreland has some remarkably fine cats, and she is in the constant habit of drowning all their progeny, except one kitten of her favourite, Mrs. Snowtip’s, which she selects with due attention to its beauty. This time, however, pussy thought proper to choose that one for herself, and carrying it from the garden into the house, she left the rest to perish. Accustomed to their being regularly taken away, she seemed to agree to that arrangement, and devoted herself to the one she had saved.

A few weeks afterwards another of the cats kittened, and its whole brood being destroyed, the poor thing became very uneasy, and suffered much from the want of her little ones to relieve her of the nourishment provided for them. On which, the fat Mrs. Snowtip being very ill-supplied herself, actually employed the poor bereaved cat as a nurse. This office she performs with proper fidelity, and the two ladies agree perfectly; for while the nurse feeds little Snowtip, the mother smooths and dresses it herself, and on any alarm flies to its protection, while the nurse seems contented with doing her own duty, and never interferes on such occasions.

_19th._--I have had a good deal of work at my strawberry bank, for Mr. Biggs warned me that the beds ought never to be dug, but constantly hand-weeded; and he recommended also that the runners should be nipped off as soon as they appeared. I undertook to do all this myself; and both weeds and runners seem determined that I shall not be idle.

This strawberry bank is such a very dry soil, that I found the plants wanted water continually; and I asked my uncle to let a little channel be made, for the purpose of bringing to the top of the bank a small rill that runs across the back of the shrubbery. Something I had heard about _irrigating_ meadows suggested this idea, and my uncle approved. The channel has been cut, and it brings the water on a level along the upper edge of my bank, from whence it trickles down the slope along each row of strawberry plants. When they have had enough, I put a slate edgeways across the channel, which acts as a little sluice, and turns the water aside into the pond. This method of watering has so far answered very well, for I think my strawberries look more healthy than any of the others; they are now in full flower, and I am in high hopes of having the first and best fruit to present to my uncle for his kindness.

_20th._--I had a long walk yesterday evening with Miss Perceval and Mary through some of farmer Moreland’s fields, which are shut up for meadow. The grasses are opening their blossoms, and Miss Perceval taught me the names of several that I had not known. She then asked me if I could describe the leading characters of the grass family.

I considered, and hesitated, and tried; but my attempts were very awkward, and I acknowledged that trials of that sort were sometimes exceedingly useful in making us acquainted with our own ignorance. She smiled, and put the same question to Mary.

Mary said, “I will do my best, but on condition that you will tell me where I am wrong. The stem is generally smooth, and its hollow cylindrical form enables it to stand upright even when four or five feet high; it is usually jointed, which gives it additional strength; and it is terminated by the flowers, which are either tufted, or in spikes, or panicled:--the leaves are alternate, and always undivided--one of them springing from each knot, and enveloping the stem with a sheath, which is split down to the knot. All grasses have a chaffy flower inclosed in a glume or husk; and each flower has a single seed. These are all the general characters that I can recollect, which mark the tribe distinctly.”

“Very clear, indeed,” said Miss Perceval, “and quite full enough. The grasses are easily distinguishable from all other plants, except the Cyperacea; and even they shew a well-marked line of separation, as their stems are sometimes triangular, and very seldom jointed; and the sheath is always entire, not split like that of the grasses.

“The grasses are of the greatest importance,” she continued, “in the economy of nature; they form in most countries the chief covering of the earth; they are the principal support of terrestrial animals; and you know that the basis of all agriculture is the cultivation of plants which belong to their order.”

Miss P. easily allows herself to be drawn out, and before we reached home, we obtained the following particulars of that numerous family.

“There are about eighteen hundred species already known; and the industry of botanists is every day adding to the list: there are both land and fresh-water grasses, but no marine grass. They occur in every soil; generally in society with other grasses, but sometimes a single species will be found occupying a considerable district. Sand appears the least favourable to their growth; but even sand has species peculiar to itself. They are spread over the whole vegetable kingdom, from the equator to the polar regions; and from the sea-shores to the tops of the highest mountains, at least to the line of perpetual congelation.

“We are still in want of a perfect natural classification, by which their distribution on the globe might be made more distinct: at present, each of the ten groups into which they are arranged, contains too many, so that not one of the groups belongs exclusively to any one zone. Some, however, may be regarded as tropical, and some as chiefly inhabiting the temperate climates. The variation of the grasses in the different continents is still less perceptible; there is scarcely any difference between those of North America and those of the temperate regions of the European continent. Between the two temperate zones also the distinction is inconsiderable. Of thirty-six species from the Cape, thirty occur in the northern hemisphere; while in other tribes of plants, Southern Africa has many that are peculiar to itself. I may mention _poa_ as being one of the most extensively distributed genera; some of its species are found in every part of the world, from Spitsbergen to New Holland.”

“We may say then,” said Mary, “that latitude has but little influence on these plants.”

“Yes, it has a decided influence,” said Miss Perceval, “on their vegetation; the tropical grasses acquire a much greater height, and almost assume the appearance of trees. Some species of the bamboo, which you know belongs to this tribe, are fifty feet high. The leaves too are broader, and approach more in form to the leaves of the other families of plants.”

I then asked Miss P. to give me some idea of the distribution of those grasses which are cultivated.

“The cultivated grasses,” she said, “which extend farthest to the north in Europe, are barley and oats. These, which in milder climates are not generally used for bread, afford the inhabitants of Norway, Sweden, and Scotland, their chief vegetable nourishment. Rye comes next to these; it is the prevailing grain along the borders of the Baltic, and in part of Siberia. Next follows a zone including Europe and a large part of Western Asia, where rye disappears, and wheat almost exclusively furnishes bread.

“The next district extends across Barbary, Egypt, Persia, and the countries of the East, where, though wheat abounds, rice and maize are extensively cultivated; and in some of those countries the sorghum, which yields a grain resembling millet, and the poa Abyssinica, are largely used by the inhabitants. In the eastern parts of the temperate zone, including China and Japan, rice predominates over all other grains. Between the tropics, maize prevails in America, rice in Asia, and both in nearly equal quantities in Africa; probably because Asia is the native country of rice, and America of maize. The native country of wheat has not yet been ascertained, but there are few places into which it has not been introduced. Several other grains and plants that supply food, are cultivated in the torrid zone, but we cannot touch on them now, as they are not grasses.

“In the Highlands of South America, there is a distribution similar to that arising from difference of latitude. Maize is not found beyond the height of six thousand feet, from thence to nine thousand feet the European grains abound, advancing upwards in this order; wheat, then rye, and then barley. The larger esculent seeds of the grasses were named, by Linnæus, Cerealia, from Ceres: he included rice, wheat, rye, barley, oats, millet, and maize.”

This morning we were talking over all we had learned yesterday from Miss P. about the grasses, when my uncle invited us to his study, and showed us some dried specimens of feather-grass which grows in Europe, and is larger and more curious than the pretty little species that you have in Brazil. The feather is six inches long, with a kind of a spiral form at the lower end, which twists or untwists according to the degree of dampness in the atmosphere. We held a piece of it over the urn at tea, by which it was instantly put in motion, so that it would make a very nice hygrometer. I wish I was acquainted with Harry and Lucy, and I would send them the bit my uncle gave me. Miss P. says that, as the seed ripens, the flower closes over it into a sharp point, and that as the stalk is slightly barbed, it works its way into the ground by the effect of damp acting on the twisted part.

_21st, Sunday._--I asked my uncle this morning to explain what he meant by the Levitical dispensation, and by the New dispensation, to which he has so frequently alluded.

“I will with pleasure, Bertha,” said he. “It gives me great satisfaction to perceive that you reflect on what you are told. Never allow yourself to be contented with half knowledge.

“You know that, in consequence of the fall of man, a system of divine grace for his redemption was promised by the Almighty; and that it commenced with the mysterious promise that the seed of the woman should bruise the head of the serpent. But as things in the natural world are only permitted to reach perfection gradually, rising from infancy to maturity, so it is, likewise, in the moral world: and this gracious scheme of mercy, instead of being at once displayed in its full extent, was gradually unfolded at different periods, until the promised seed was at length manifested in Jesus Christ. These successive communications have been called dispensations, because the knowledge of God and of his merciful intentions were _dispensed_ or revealed by them. There have been three of these dispensations, the patriarchal, the Levitical, and the Christian; but they belong to the one system of Providence, and are all linked together, the redemption of the human race being the beginning and the end of the whole. The proper modes of worship were at the same time distinctly ordained; and, however different the institutions which were severally dispensed may appear to us, we may feel assured that each of them was peculiarly adapted to the moral state of the world when it was promulgated.

“During the term of the patriarchal dispensation, which comes first in order, it pleased God to make known such a portion of his will, and to dispense throughout the world such a degree of knowledge of his purposes, as would have been abundantly sufficient to have conducted mankind to heaven, if they had not wilfully resisted the benevolent offers that were made to them, and turned aside from the easy path of duty that was prescribed. The patriarchal dispensation was evidently intended to be _universal_ in its offers, as well as in its conditions; for Adam would of course communicate to the numerous generations of his children, with whom he was contemporary, the knowledge, which he had himself derived from direct revelation, of God’s gracious will and intentions. But this universality was of short duration. Animal sacrifice appears to have been appointed as a type of that mighty sacrifice or atonement by which mankind were to be enabled in the fulness of time to triumph over their spiritual enemy; and the conduct of Cain in rejecting it produced an immediate distinction between the servants of God and those who were seduced to follow the principles of his apostasy. The terms on which that general atonement had been offered were neglected; the reconciliation of fallen man by means of the promised seed was slighted, and the lamentable corruption which spread amongst the early inhabitants of the world led to the awful judgment of the Deluge.

“Thus ended the first period of the patriarchal church. It was renewed in the descendants of Noah, and for a long period retained its original character of universality, till other apostasies took place. These, however, were of a very different nature from that of Cain. The occasional appearances of a superior race of beings, ministering under a human form between God and his creatures upon earth, probably led to what has been called Hero-worship. Surprising as this perversion may appear among people whose immediate ancestors had the singular advantage of direct communication with the Supreme Being, it seems to have taken deep root in the human mind; for, in the most enlightened nations of antiquity, we find a continual disposition to look back on departed heroes and conquerors, not only with a sort of pious veneration, but even to consider and address them as tutelar deities. Always prone to be led away from the plain and simple truth, human weakness found another early source of corruption in the worship of the heavenly bodies: their splendour, and their obvious influence on all the pursuits of mankind, produced a superstitious reverence, which by an easy transition degenerated into adoration; and it has been remarked, that in the early records of almost every country we find that the sun and moon were regarded as deities; and that fire was the constant emblem under which they were worshipped.

“The prevalence of these idolatries after the deluge may be inferred from various passages in the Scriptures; and particularly from the direct prohibitions contained in the laws that were given to Moses. But amidst all the depravities and abuses that had thus disfigured the patriarchal religion, the belief in the necessity of expiatory sacrifice was constantly maintained; and though the horrid corruption of that tenet gave rise to the sacrifice of human victims, there is no doubt that they dimly shadowed out a general belief in a future divine victim. Thus you perceive that, revolting as all these impious corruptions were, yet they had for their original foundation the very principle of the system of atonement and redemption; that ‘without shedding of blood there is no remission of sins.’

“The consideration of the other two dispensations we must defer, my dear Bertha, to another opportunity.”

_22nd._--Mary and I went this evening in search of the moth of the little pear-leaf caterpillars: we shook a gooseberry-bush, and numbers of them came forth. They fly in the day-time, never going far at a time, and cautiously conceal themselves in the nearest bush.

This little (_seratella_) moth is of a brownish colour, with numerous black dots and stripes on the fore wings, which are beautifully fringed with feathers. The inferior wings are very small, and have also a fringe on the margin. This moth is particularly distinguished by the extreme length of the hind feet; they are twice as long as the body, and are thought by some to act like a pair of oars in regulating their flight, and in helping to maintain the body in equilibrium.

My aunt told me that some years ago the depredations of this insect were considered as a species of blight, and the insect was so little known, that no description of it was to be found in either French or English entomologies. She believes that every blight that affects our fruit-trees is produced by insects, whose visits are encouraged by certain dispositions of the atmosphere. The germs of the future race are lodged ready to be called into existence whenever the weather be favourable to them. The cure then must be to eradicate the germ, but this can only be known by tracing the habits of these minute creatures. “What a field,” added my aunt, “for exercising the industry and observation of young people; and not only in acquiring knowledge, but in turning that knowledge to useful purposes.”

_24th._--We accompanied my aunt and uncle yesterday in a very pleasant expedition. We boated to Elmore early in the morning to breakfast with Mrs. Maude, and heard some very entertaining letters from her daughter, which she was so kind as to read to us.

Miss M. has been in town for three weeks, and the friends she is with have made great exertions to shew her every thing interesting. In the midst of all her hurry, however, she has written constantly home, describing all she does, and sees, and thinks, that can interest her father and mother. She was not very fond of early rising; but now, in order to prevent any thing from interfering with these letters, she has the resolution to get up and write them before her friends’ breakfast hour. She has almost excited my envy by her repeated visits to the British Museum--to galleries of beautiful paintings--to botanic gardens and stoves--to collections of beasts, and birds, and insects,--to tunnels and suspension-bridges, and to all sorts of curious machinery; and she has had the great advantage, too, of having seen all these things in company with people who could explain them to her. Alas! such things can be found only in London.

After we had heard these letters, we went on to Gloucester, where I had not yet been; and though it was not London, I had the pleasure of seeing a great deal that was quite new to me, and very interesting.

The pin manufactory we saw in every part, from the straightening the brass wire before it is cut into the proper lengths, to the last operation, by which the pins are whitened. But as Marianne will find all the particulars detailed in the Book of Trades, I will only say, that the thing which seemed to shew the most expert fingers, was the putting the pins into the heads, and riveting them by a slight blow on an anvil. This is done by children, who take the heads out of an iron pot in which they have been heated, and instantly pop the bits of wire into them; and the never-failing exactness with which it is done is really wonderful. My uncle afterwards told us that a patent has been lately obtained for a very ingenious improvement, by which the head is raised upon the wire itself, so that the whole pin consists of a single piece of brass.

The sticking the pins into the papers, which are folded and placed against the edge of the bench, is also very curious. And when I recollected the great variety of people who had been employed in preparing the materials from the time the metals were dug out of the mine till the wire was drawn, along with those whom I had just seen engaged in the different operations in this manufactory, I could not but feel astonished that one small article of female dress should cost such accumulated labour.

We then walked to the cathedral. What a magnificent building, mamma! the twelfth part of a mile in length, and more than two hundred feet high. As to the interior, it is grand beyond any thing I can attempt to describe, but you must remember it too well to make that necessary.

I will mention, however, a curious circumstance that my uncle told me as we were passing among the monstrous pillars of the nave: an attempt was made not very long ago to reduce them in size, or to chisel them into cluster columns; but they were found to be only hollow cases of masonry filled with loose stones. I could not help feeling glad that it had failed, for the contrast of their heavy, solid appearance, with the light elegance of the cloisters, I think improves each other. The choir is beautiful; and often as my aunt and uncle had seen them, they could not help stopping to admire the carved work and tracery of the stalls.

This fine cathedral was begun in the eleventh century, the cloisters were added in the fourteenth, and the west front was not completed till the fifteenth. My uncle took the opportunity of shewing me the different styles of Gothic architecture belonging to those periods; and on our road home, he explained the principal distinctions between the Saxon, Norman, and English styles, and the gradual alteration of the circular, sharp pointed, and flat arches. The subject was entirely new to me, but I felt so much interest in it that he has promised hereafter to go through a little course of architecture with me, from the Egyptian and Grecian to the Roman and Gothic.

_25th._--We were talking to-day about the impressions of plants perceptible in coal, and I asked my uncle to tell me what plants they were; he referred me to Miss Perceval, who says that it appears from the researches of several German botanists, and particularly from those of Dr. Martius, that some of the Brazilian plants, which are so familiar to us, dear mamma, seem to have such a resemblance to those impressions, that there can be scarcely a doubt of their identity.

“The tree ferns,” she said, “exhibit several characters in common with those ancient plants; one species in particular, the stem of which having a remarkable _tessellated_ or chequered appearance, exactly represents some of the petrified forms found in the German coal mines. Dr. Martius describes ten different kinds of fern found in coal, each distinctly marked by some of those peculiarities which distinguish the living plants.

“As very numerous examples of the arborescent as well as the herbaceous ferns occur in the coal formation, it can scarcely be doubted that this order of plants was formerly much more numerous than it is now; and that the forests of the primitive world were abundantly stocked with them.”

“That is the more probable,” said my uncle, “as there is reason to suppose that ferns were among the first plants that spread over the surface of the globe, and that they were the basis of a more general vegetation, by preparing the ground for others. Their large fronds probably deriving as much nourishment from the atmosphere as from the earth; while their annual decay rapidly increases or improves the productive soil.”

“I do not mean, however,” said Miss Perceval, “that the antediluvian woods consisted entirely of ferns; for the remains of many other plants, and of some large trees, are found mixed with those of fern--just as the living woods of the equinoctial regions, though very rich in ferns, consist of a great variety of plants of all sizes. Several specimens of palms, and of bambusæ, have been discovered; and the cactus is another tribe which appears very abundantly amongst these petrifactions.”

“And I believe,” said my uncle, “that the remark I made respecting ferns may be repeated of those tribes,--that they are furnished with a singular structure of organs adapted for respiration, and thereby for inhaling nutritious juices from the atmosphere.”

“Yes,” said Miss P., “Saussure found that a single leaf of the cactus opuntia inhaled four cubic inches of oxygen in the course of a night from the atmospheric air in a glass vessel, in which he inclosed it; and we may, therefore, consider those tribes, and the yuccæ, and lychnophoræ, which flourish in a dry sandy soil, as the pioneers of vegetation, and intended by Nature to inhabit the rude wastes of a new world.”

After some further conversation on this subject my uncle said, “As the delicate parts of any vegetable substances would be entirely destroyed if transported to a great distance by floods, it is evident, that those plants, whose remains are found well preserved in a fossil state, must have been inhabitants of the countries where the strata were formed. This consideration has given rise to many interesting speculations on the former climate of Europe, and its apparent changes; but if mammoths and elephants were clothed with fur to enable them to endure a Siberian winter, why may we not suppose that there were also species of palms and tree ferns suited to our temperate regions? Another curious inference may be drawn from the examination of vegetable remains: those found in what the German mineralogists call brown coal, exhibit in their wood, in their fruit, and their leaves, sufficient proofs of their belonging to indigenous, or, at least, to modern races of plants; while those which occur in what is termed black coal are all unknown or exotic: there can be no doubt, therefore, that those two coal formations belong to two very different ages of the globe.”

_26th._--I still find a great deal of amusement in watching my little family of swallows. They are unwearied in collecting food for their young; skimming through the air from morning till night, and darting on their prey with the most sudden turns. They catch gnats and flies, and consume an astonishing number of mischievous grubs; and I am told they often accompany people on horseback, through the fields, in order to pick up the flies which are roused from the turf by the horses’ feet.

They never touch seeds; insects are their only object, and according to the weather, or the degree of warmth, they sometimes skim along the surface of the ground, and sometimes fly at a great height. When there is a scarcity of insects they have been known to snatch the flies imprisoned in a spider’s web, and sometimes even the spider itself.

Another species arrived soon after the chimney swallow, which I believe I have already described to you. It is called the house martin, or window swallow; but there is no end to the number of names given to this bird. It is very like the chimney swallow, but it has no spots on the tail, and its feet are differently formed, for it has the power of turning the hind toe forwards, in order to cling to a wall. This species are chilly little creatures; when there is a cold wind or rain, they press close to one another, and are sometimes so benumbed as to be caught by the hand.

It is said that after they arrive here in April, they play about for nearly a month before they begin their nests. Sometimes they build in the cliffs and rocks that hang over water; sometimes against a perpendicular wall, without having any support underneath the nest; and they show great sagacity in their mode of carrying on their work. While laying the foundations, they not only hold on by their claws, but they fix their tail against some little projecting roughness in the wall to serve as a kind of prop; and then with their bill they carefully cram mud and bits of straw into the smallest chinks in the face of the brick or stone; and to give those materials time to harden preparatory to a fresh layer, the prudent little mason only labours early in the morning, so that his work dries sufficiently in the course of the day. I have got up several times at day-break to see how neatly he uses his bill as a little trowel, while he carries the mortar or clay in one of his feet. About half an inch is laid every morning; and in ten or twelve days, a hemispherical nest is thus formed with an aperture at the top. The shell or crust is covered with rough knobs of earth; the middle is strengthened by the intermixture of straw; and the inside is nicely lined with grass and feathers; or sometimes with moss and wool. If by any accident the nest should be destroyed, it is rebuilt in a short time by the active help of many individuals who unite to assist their distressed companion. For several mornings they persisted in rebuilding a nest at the passage-room window, which had been purposely torn down each day; but, at last, after a hard struggle they gave it up.

I understand that the _cliff_ swallows of America--who place their nests close up to the jutting ledge of a rock, or to the eave of a house--most ingeniously arch the top, and make the entrance project out and turn downwards. Frederick, who mentioned that circumstance at dinner, very philosophically remarked that, while the population of Europe was steadily extending itself from the eastern shores of America to the western side of the Mississippi, those cliff-swallows were as resolutely advancing in a contrary direction. “It appears,” said he, “from C. Buonaparte’s ‘Ornithology,’ that in ten years they had gradually established themselves in Kentucky and Ohio; in 1817 a single bird was seen skimming round a tavern, near Lake Champlain--the next year, seven were observed there--the third year, twenty-eight--and in 1822, no less than seventy had arrived in April, which is the usual time of return from their migratory travels.”

The common sparrow sometimes seizes on a swallow’s nest, before it is completed; and having driven away its owner, adapts it to his own use; but such invasions are often repelled after a spirited contest. This act of piracy has been frequently seen; but my aunt is inclined to doubt the truth of another story, though related by Linnæus, of a sparrow who took possession of a martin’s nest, and obstinately resisted the united efforts of a group of these birds which had come to the aid of the owner; but, at length, they immured the intruder by building up the entrance with the same kind of mortar of which the nest was composed.

I can see the little swallows sitting all day with their heads out of the nest near my window, gaping for their parent, who comes frequently to them with food, and clings to the edge while they gobble it up; and I understand, that after they begin to fly they are fed by their parents on the wing. I have watched for this, but could not perceive it, they are so quick in every movement. As soon as the first family are able to provide for themselves they quit their home, and while they are sporting about, and clustering and hovering round every building in the neighbourhood, the mother repairs the nest for a second brood.

_27th._--The spring is now rapidly changing to summer, and the opening buds and unfolding leaves have been succeeded by a profusion of young branches, and flowers. It is, indeed, very different from the rich luxuriant spring of your Brazilian climate, but on the other hand, we have not here the perpetual rain, and the oppressive closeness of that season. The freshness of the air, the fragrance of the flowers, and the sweet song of the birds are all delightful; and every day I see some new and pretty insects. Though these insects are not quite in such numbers as, Humboldt says, appeared by turns, each at their different hours, on the Amazon river, still one may say--

Ten thousand insects in the air abound,
Flitting on glancing wings that yield a summer sound.

Just as we were looking at an uncommon butterfly to-day, Mr. Maude paid us a visit, and seeing how we were occupied, he told us that when travelling in Switzerland last June, he witnessed a very curious circumstance, in the Canton de Vaud; an emigration of butterflies. He happened to perceive something flying past the windows, and on looking out he discovered an immense flight of butterflies crossing the garden. He immediately went out, and found that they belonged to the species called, in French, La belle Dame; they were all going in the same direction, exactly from South to North, turning neither to the right nor left; people moving about the garden did not frighten them; nor were they even tempted by the numerous flowers there to alight. Their flight was low and steady, but extremely swift; and it continued in a column of several feet broad for more than two hours. As Mr. M. afterwards learned that these butterflies had been remarkably abundant near Turin, in April and May, he supposes that they had emigrated from Italy; but, he says, naturalists have been greatly puzzled to account for their having done so in a body, because they do not belong to those species that live in societies.

He mentioned another singular circumstance: when he was on Mount Etna, he saw, to his great astonishment, an immense number of insects hovering over the dry lava of one of the old craters; there was no appearance of vegetation, or of any thing that could supply them with food; but there they were in a thick mass, flitting about in the sulphurous vapour, which still rose from the crevices. The insect was a species of bug, or _cimex_.

Frederick took me this evening to a sunny sand-bank, to shew me a great novelty, which he had discovered there; the nest of the _mason wasp_. It is not common in England, and has never been found in this part of the country before. The nest is a round cavity, from two to three inches deep; which the insect bores through a hard sandy soil; and instead of throwing away the sand, as it is dug out, the little mason, by means of a glutinous fluid, forms it into oblong pellets, and arranges them round the entrance of the hole, so as to form a sort of cylindrical tunnel; which sometimes, Frederick says, is about two inches long. These little pellets are so nicely attached to each other, with regular spaces at the corners, that they have quite the appearance of filligree work. It is said that the use of the tunnel is to prevent the incursions of ichneumons, and other artful insects, who are always on the watch to intrude their own young, and who are perhaps deterred by the artificial look of this entrance. One egg only is placed in the nest; and along with it are stored, as food for the future young, several fat grubs. But these are always full grown, because, as they are just about to pass into the pupa state, they require no food for themselves.

Frederick opened the nest; and we examined it without fear, because the mason wasp having deposited its egg, and supplied it with food, does not remain to guard it. We found twelve grubs closely packed; each of them being coiled above the other in a succession of rings, and the earth so pressed on them as to prevent their movements from injuring the egg. The remainder of the hole was filled up with some of the pellets that I have already mentioned.

_28th, Sunday._--This morning my uncle proceeded to explain the Levitical dispensation. He began by reminding us of the gross corruptions, which had again crept into the Patriarchal dispensation, notwithstanding the awful warning of the flood.

“But,” said he, “even in those corruptions the main principle of that dispensation was preserved; that principle which marked the fallen state of man, and to which every hope of future pardon was necessarily attached. Instead of rejecting that doctrine of the atonement and the hope of the promised Deliverer, the apostates of that age made those points the very basis of their heresy. Their creed was built upon the necessity of expiatory sacrifices; and, though they impiously divided and multiplied their hero-gods at pleasure, still each remotely signified the predicted seed of the woman supposed to be corporeally manifested in this, or in that illustrious human character. The Almighty, however, had declared that there should not ‘any more be a flood to destroy the earth.’ In his merciful councils other means were adopted for counteracting the evil, and for reclaiming mankind from a depraved polytheism, in which the true belief would be altogether lost; and with it the only means of ultimate reconciliation. The Patriarchal dispensation was no longer suited to this altered state of the world, nor sufficient for this gracious purpose; it was, therefore, to be superseded by a new and intermediate dispensation, which should strongly inculcate the doctrine of the Divine Unity, and perpetuate and confirm with unceasing light, from time to time, the true original doctrine of redemption. Such was the object of the _Levitical_ dispensation.

“The dispersion of the people at Babel had spread the corruptions of which they had been guilty, over the face of the earth; and it pleased God to separate from them one family who were to be the depositaries of that peculiar principle which was to give efficacy to all religious duties. For this purpose Abraham was selected from amongst the idolaters of Babylonia, to be the father of a nation to which the new dispensation was to be committed. They were to preserve the true principles of religion for the rest of the world; and from them that Messiah was to proceed whom they never ceased to desire, though they so strangely misconceived his real character, and debased the sublime object of his mission.

“The Patriarchal religion had been originally conferred on all mankind; its principle was universality: but that being now changed, and a single people being chosen out of the corrupt mass, in order to preserve the truth, we may say that the chief distinction between the two dispensations was, that the first was _universal_, the second _particular_.

“The law as delivered by Moses, and called the Levitical dispensation, because its ordinances were confided to the tribe of Levi, was not sent to do away the original religion, nor was it intended to supply new motives, or new sanctions. The law did not reveal the doctrines of the Divine Unity; or of redemption through a promised Deliverer; or of a state of future reward and punishment--for they had been already established; but to those great doctrines the law ‘was added, because of transgressions[8].’ It was _added_, in part to preserve the knowledge of the Divine Unity in the midst of surrounding superstitions; in part to preserve the doctrine of redemption amidst the idolatrous Gentiles; and also, by imposing on the Israelites numerous observances and restrictions, to preserve them separately from the world, a peculiar people; as Balaam said, ‘Lo, the people shall dwell alone, and shall not be reckoned among the nations.’

“But as the time drew near when the sun of righteousness was to rise, the characteristic of particularity began to be withdrawn from the Levitical church. The light of the gospel was preceded by a faint knowledge of the truth which began to spread into other parts of the world. The Babylonish captivity left some traces of it in the East; the emigration of numerous Jews into Egypt carried it there likewise; and the translation of the Hebrew Scriptures into Greek opened the eyes of many pagans, so that several proselytes to the worship of Jehovah were received into the Levitical church.

“Such were the preparatory steps to the abolition of paganism, and to the introduction of the last, and most important, of the three dispensations; that which was to do away with all other codes and rituals--which was to put an end to all emblematic sacrifices--and which was to collect into one fold, under one shepherd, all the nations of the earth.”

_29th._--This evening I was talking away at a great rate to Caroline--probably a great deal of nonsense--and having frequently used the expressions, I conceive, I imagine, my uncle at last asked me if I could explain the distinction between those two words.

I considered for a little while, and then said, that though I had been using them very negligently, yet I thought I could point out the principal difference.--_Conception_ is the calling up an absent but distinct idea of something we have already perceived or felt--a complete picture in the mind of some former sensation. But by _imagination_ we take a bit of one of these pictures and a bit of another--we select different circumstances from a variety of things that we have seen--and by combining them together according to some particular view, we form a new creation, and obtain the idea of something that we have not seen.

“Very well, my little Bertha,” said my uncle smiling, “I like to see you exert your mind: but I would alter one part of your definition--I would not confine the imagination to objects of sight only; for though the mind dwells with greater facility on those that have been supplied by that sense, yet it is equally certain that our other perceptive faculties contribute their share also. The least imaginative person must recollect the many pleasing images which have been excited by the fragrance of distant fields, and the melody of unseen birds; and if you will accustom yourself to examine the process of your own imagination, you will find that an ample proportion of the subjects which pass through it are derived from all your senses.”