I obtained sapotin for the first time by heating dry raspings of the almond with 90 per cent. alcohol. While cooling, the filtered liquid deposited a good deal of the compound. Since that time I have advantageously modified the process and increased the amount of product. I prepare sapotin in the following way: The almonds are rasped, dried at 100 deg. C. and washed with benzene, which takes away an enormous quantity of fatty matter. The benzene which remains in the almond is driven put first by compression, afterward by heating. Then the raspings are exhausted with boiling 90 per cent. alcohol. The solution is filtered as rapidly as possible, in order to avoid its cooling and depositing the sapotin in the filter. As soon as the temperature of the filtered liquid begins to fall, a voluminous precipitate is seen to form, which is the sapotin. In order to purify it, the precipitate is collected in a filter and expressed between sheets of filter paper. When dry it is washed with ether, which takes away the last particles of fatty and resinous matter. The purification is completed by two crystallizations from 90 per cent. alcohol. At last the substance is dried at 100 deg.. The sapotin separates from its alcohol solution in the form of microscopic crystals. When dry, it is a white, inodorous powder. Its taste is extremely acrid and burning. If the powder penetrate into the nostrils or the eyes, it produces a persistent burning sensation which brings about sneezing and flow of tears. It melts at 240 deg. C., growing brown at the same time. It has a laevo-rotatory power of [a]_{j} = -32.11, which was determined with an alcoholic solution, the aqueous solution not being sufficiently transparent. It is very soluble in water, easily soluble in boiling alcohol, much less in cold alcohol, and insoluble in ether, chloroform and benzene. Its alcoholic solution is precipitated by ether. Tannin has no action on it, but basic acetate of lead produces a gelatinous precipitate in its aqueous solution. Strange enough, this precipitate is entirely soluble in a small excess of basic acetate of lead. If thrown into concentrated sulphuric acid, sapotin colors it with a garnet red tint. It does not reduce Fehling's solution. Its analysis gave the following results: Calculated for Found. C_{29}H_{52}O_{20}. I. II. C 48.33 48.69 48.31 H 7.23 7.33 7.45 When heated with water and a little sulphuric acid, sapotin is decomposed and yields glucose and an insoluble matter which I call _sapotiretin_. One hundred parts of sapotin produce 51.58 parts of glucose and 49.67 of sapotiretin. The equation which represents this reaction is: C_{29}H_{52}O_{20} + 2H_{2}O = 2C_{6}H_{12}O_{6} + C_{17}H_{32}O_{10} and requires 50 per cent. of glucose and 55 per cent. of sapotiretin.