308 Dr. Smith on the Composition of Spermaceti. 



The physical properties of this acid will be seen to differ from 

 those of margaric acid, which it has been supposed to be, but 

 there is no striking difference between these two bodies in com- 

 position, as will be seen in the results afforded by the analysis of 

 this body. 



Exp. 1. 0.2815 grammes of the acid burnt with the bioxide 

 of copper gave* 0.7725 gram, carbonic acid and 0.320 gram, 

 water. 



Exp. 2. 0.2325 gram, of the acid burnt with the bioxide 

 of copper gave 0.637 gram, carbonic acid and 0.261 gram, wa- 

 ter. 



Exp. 3. 0.328 gram, of the acid burnt with the chromate of 

 lead gave 0.890 gram, carbonic acid and 0.3685 gram, water. 



These three analyses furnish the following proportions of car- 

 bon, hydrogen, and oxygen, in 100 parts of the acid. 



Carbon, 75.44 75.31 74.64 75.13t 



Hydrogen, 12.60 12.47 12.46 12.51 

 Oxygen, 12.96 12.22 12.90 12.36 



100.00 100.00 100.00 100.00 

 Having thus found the relative proportions of the elements 

 contained in this acid, it was necessary to examine one of its salts, 

 to ascertain its atomic composition, and for this purpose, as in 

 most cases, its combination with the oxide of silver was chosen, 

 but to form this salt it was necessary first to form its soda salt. 



Soda Salt. — A portion of the acid was digested with a solution 

 of carbonate of soda, until a complete combination had taken 

 place, which is easily known by the acid no longer floating on 

 its surface, it having all united with the soda, forming a salt solu- 

 ble in water. The solution of this salt, which contained an ex- 

 cess of carbonate of soda, was evaporated to dryness in a water 

 bath, and the dry mass, pulverized, was treated with absolute 



* All my calculations are made with the atomic weight of carbon given by Lie- 

 big and Redenbacker, (75.85 oxygen being considered 100, or 6.068 hydrogen be- 

 ing taken as unity.) 



t Composition of margaric acid after the analysis of Varrentrapp — 



Carbon, 75.35 



Hydrogen, . 12.33 



Oxygen, ........ 12.32 



100.00 



