Additional tests for cholesterol have been recently proposed by Lifschuetz (_Ber. Deut. Chem. Ges._, 1908, 252-255), and Golodetz (_Chem. Zeit._, 1908, 160). In that due to the former, which depends on the oxidation of cholesterol to oxycholesterol ester and oxycholesterol, a few milligrammes of the substance are dissolved in 2-3 c.c. glacial acetic acid, a little benzoyl peroxide added, and the solution boiled, after which four drops of strong sulphuric acid are added, when a violet-blue or green colour is produced, if cholesterol is present, the violet colour being due to oxycholesterol ester, the green to oxycholesterol. Two tests are suggested by Golodetz (1) the addition of one or two drops of a reagent consisting of five parts of concentrated sulphuric acid and three parts of formaldehyde solution, which colours cholesterol a blackish-brown, and (2) the addition of one drop of 30 per cent. formaldehyde solution to a solution of the substance in trichloracetic acid, when with cholesterol an intense blue coloration is produced. _Water._--From 5 to 20 grammes of the fat or oil are weighed into a tared porcelain or platinum dish, and stirred with a thermometer, whilst being heated over a gas flame at 100 deg. C. until bubbling or cracking has ceased, and reweighed, the loss in weight representing the water. In cases of spurting a little added alcohol will carry the water off quietly. To prevent loss by spurting, Davis (_J. Amer. Chem. Soc._, 23, 487) has suggested that the fat or oil should be added to a previously dried and tared coil of filter paper contained in a stoppered weighing bottle, which is then placed in the oven and dried at 100 deg. C. until constant in weight. Of course, this method is not applicable to oils or fats liable to oxidation on heating. _Dregs, Dirt, Adipose Tissue, Fibre, etc._--From 10 to 15 grammes of the fat are dissolved in petroleum ether with frequent stirring, and passed through a tared filter paper. The residue retained by the filter paper is washed with petroleum ether until free from fat, dried in the water-oven at 100 deg. C. and weighed. If the amount of residue is large, it may be ignited, and the proportion and nature of the ash determined.