164 SAPONIFICATION. [ VI. 



ing as such naturally in the oil. He draws the inference, 

 therefore, that the SOg combines with the aldehyde, or rather 

 with the oxide of caprinyle CgoH^^gO, and that this compound, 

 upon the addition of a base, is decomposed, and aldehyde 

 separates. 



Castor eum Canadense. — F. Wohler has by recent examina- 

 tions (Liebig's Annalen, Ixvii.) confirmed the supposition that 

 the odor of castor is due to the presence of carbolic acid. He 

 also found that it contains salicin and benzoic acid. Carbolic 

 acid is obtained among the products of coal-tar. 



Adulteration of Attar of Hose. — Guibourt ( Journ. de Pharm. 

 1849), after showing the unreliableness of the physical cha- 

 racters, as a test of purity, because of the readiness with 

 which they may be imitated, proposes three tests for dis- 

 tinguishing the true attar. The usual adulterants are oils of 

 rosewood and geranium. They may be detected as follows : 



Bt/ Iodine. — The suspected attar is placed in watch-glasses, 

 under a bell, along with a capsule containing iodine. The 

 vapors of iodine, after some hours, condense, and form a brown 

 areola upon the oil, if adulterated, but do not change its 

 color, if pure. On exposure to air, the iodine volatilizes, but 

 the color, in either case, remains unaltered. 



Bt/ Nitrous Acid. — This serves only to detect the oil of 

 geranium, to which it imparts an apple-green color ; as it 

 tinges the attar and oil of rosewood alike dark-yellow. 



By Sulphuric Acid. — This reagent turns all three of the 

 oils brown, but the attar retains the purity of its odor, while 

 that of the oil of rosewood is rendered more perceptible ; the 

 geranium oil, at the same time, acquiring a strong and un- 

 pleasant smell. 



Sandal Wood. — According to Meier, there are six different 

 substances in sandal-wood. (Ch. Gaz. vii. and Archiv. der 

 Pharm. Iv. and Ivi.) 



1. Santalic acid, extracted by alcohol, in microscopic prisms 

 of a beautiful red tint, soluble in alcohol and insoluble in 

 water, and forming deep-violet salts with the alkalies. 



2. Santalic oxide, also extracted by alcohol; a brownish 



