“In the ground spices it will be found more difficult to recognise the anatomy of the parts than in a carefully prepared section. The hardest parts are often the largest particles, and scarcely at all transparent. The mounting of the material in water or glycerine will render them more so, but it is necessary to employ some other means of which two are available. A solution of chloral hydrate in water, 8 to 5, serves after 24 hours to make the particles less obscure. In many instances also, it has been found advisable to bleach the deep colour by Schulze’s method, using nitric acid of 1·1 sp. gr. and chlorate of potash. When this is done, hard tissue is broken down and rendered transparent where otherwise nothing could be seen. As examples, olive stones and cocoa-nut shells will serve. Without treatment little can be made out of their structure. “Of course, it is plain that the detection of starch must be in a portion of the material which has received no treatment, and that progress must be made from the least to the most violent reagents. “For this work an elaborate microscope is unnecessary. It should, for work with starches, have objectives of ½ and 1/5 inch equivalent focus, arrangements for polarising light, and if possible, a condenser system. Many good stands are to-day made at reasonable prices which will serve the purpose.” The microscopical appearance of various starches in polarised light is shown in Plate IX. Plate XII. exhibits several spices, under polarised light, in a pure and adulterated state. Those represented are:-- Ginger, pure, and adulterated with foreign starch. Cinnamon and Cassia; the pure barks, ground, showing the relative greater frequency of fibro-vascular bundles in the former. Cayenne, pure, and adulterated with rice starch. The chemical analysis of spices, although usually of minor importance, often serves to confirm the results secured by aid of the microscope. The principal determinations required are the ash, oil, starch, and sugar. The more common forms of spice adulteration are the following:-- _Cloves._--This spice is said to be sometimes deprived of its volatile oil before being put on the market. In the genuine article the proportion of oil seldom falls below 17 per cent. The oil is readily estimated by distilling the suspected sample with water. The usual adulterants of ground cloves consist of clove-stems, allspice, flour and burnt shells. PLATE XII. [Illustration: Ginger Starch.] [Illustration: Ginger Adulterated.] [Illustration: Cinnamon.] [Illustration: Cassia.] [Illustration: Cayenne.] [Illustration: Cayenne Adulterated.] SPICES. _Mace._--True mace is frequently mixed with the false spice, the presence of which is indicated by its dark-red colour. The other foreign substances most commonly used are turmeric, wheaten flour, rice, corn meal, and roasted beans. _Cinnamon._--The chief admixtures to be sought for are cassia, ground shells, crackers, etc.