Freely soluble in spirit and in glycerine, insoluble in ether, fats, and oils, and therefore it is not so compatible with them. This salt will crystallize with two molecules (9·5 per cent.) of water, but the anhydrous salt alone is official. It dissolves with effervescence but without colour in cold sulphuric acid (_see_ Cocaine, p. 56), but chars if heated. Ignited in the air, it burns without residue. Its aqueous solution gives a white precipitate with carbonate of ammonium, soluble in excess. If one drop of solution of permanganate of potassium, B.P., be added to a solution of 1 grain of it in a drachm of distilled water, acidulated with three drops of diluted sulphuric acid, the bright deep colour of the solution, if kept covered, should not change during half an hour, indicating absence of other alkaloids of Coca, or any other organic matter. The salt should not only be in good crystals, but should yield a distinctly crystalline precipitate of pure cocaine within three minutes, when 1 grain of it is dissolved in 2 ounces of distilled water, and six to eight drops of solution of ammonia, B.P., are added and well stirred. The precipitate redissolves after twenty-four hours or more, the cocaine being converted into methyl alcohol and benzoyl-ecgonine.—P.J. 1888, 783. If a trace be mixed with a minute quantity of calomel and breathed upon, the mixture assumes a black colour. This will only answer with the salts of cocaine, not with the alkaloid itself. As with an aqueous solution of sulphate of atropine, so with an aqueous solution of hydrochlorate of cocaine, some samples seem prone to grow fungi, while others will not. Evil results having followed the application of Cocaine as a local anæsthetic in several dental and eye operations, the bad effects have been attributed to these fungoid growths. Whether due to these, to impurity of the salt, or to the condition or idiosyncrasy of the patient, is not clear. Three London surgeons who have used it very largely inform me they have never seen any untoward results from its use in simple aqueous solution. Various modes of keeping the solution free from fungi have been suggested; carbolic, boric, and benzoic acids, perchloride of mercury, thymol, camphor, and chloroform have been added to check their growth; a half to one per cent. of boric acid has been particularly recommended, but it is of little use, as an aqueous solution of boric acid itself sometimes grows a fungus; chloroform is probably unobjectionable except for eye drops. Perchloride of mercury is useless, as it forms a double salt with the Cocaine. But salicylic acid has been found to be the most effective, and its addition is now ordered in the official solution. (See p. 60.) _The brush applying it should not be dipped in the stock solution._ =Buginaria Cocainæ Hydrochloratis=, NASAL BOUGIES OF HYDROCHLORATE OF COCAINE.