Chapter I

A FLUID PASTE is made by pouring into a porcelain jar 5 kilogrammes of potato-starch with 6 kilogrammes of water and 250 grammes of white nitric acid. Keep the whole in a warm place for forty-eight hours, stirring it frequently, and then boil it till syrupy and transparent. Add a little water, or sufficient to make it fluid enough to be filtered through a closely woven towel.