Wool in its unwashed state contains a considerable proportion of what is termed _suint_. This consists of the fatty matter exuded as perspiration from the sheep, along with, or in some form of combination with, potash derived from the grass on which the sheep feed. _Suint_ was first investigated by Vauquelin. He obtained it by evaporating, after filtration, the water in which raw fleeces had been washed. The residue is of a brown color, and has a saline, bitter taste. On addition of an acid to its solution in water, it coagulates, and a fatty matter rises to the surface. It is, in fact, a potash soap, to a great extent containing carbonate and acetate of potash, along with chloride of potassium and lime, probably in combination also with fatty acids. It is usually mixed with sand and carbonate of lime. In 1828, M. Chevreul, who is still alive in Paris, although nearly a century old, published an analysis of merino wool. It consisted of: Per cent. Pure wool 31.23 Soluble _suint_ 32.74 Insoluble 8.57 Earthy matter 27.46 ------ 100.00 It is easily seen that _suint_ forms a very important constituent of raw wool. Its proportion varies, of course, according to the nature of the pasture on which the sheep are fed, the climate, etc. Wool from Buenos Ayres, for example, contains much less than that analyzed by M. Chevreul; its amount is only 12 per cent. of the weight of the raw wool. This _suint_ contains always about 52 per cent. of residue when ignited. The composition of this residue is: Per cent. Carbonate of potash 86.78 Chloride of potassium 6.18 Sulphate of potash 2.83 Silica, alumina, etc. 4.21 ------ 100.00