108 Di". L. PI ay fair on a new Fat Acid 



Prof. Redtenbacher has shown* that stearic asther is a com- 

 pound of stearate of the oxide of ethyle with the hydrate of 

 stearic acid, and represented by the formula 2 ^t Ae O 

 + 3 HO. As stearic acid is a bibasic acid, four atoms of 

 base are combined with two of acid. Sericic aether is a body 

 of an analogous composition, and forms a true double salt — 

 sericate of oxide of ethyle and sericate of water. Its formula 

 therefoie, is (Se + Ae O) + ( Se H- H O) . 



Two atoms of sericic acid ... = Cgg, H54, Og . 

 One atom of oxide of ethyle = C 4 , H 5 , Oj . 

 One atom of water = H , ,^0, . 



Sericate of the oxide of ethyle = C^o , Hgg , Og . 



The formation of sericic aether may be easily explained ; 

 the muriatic aether, formed by passing muriatic acid gas 

 through a solution of sericic acid in alcohol, is decomposed 

 by the fat acid; sericic asther is thus produced, and attaches 

 itself to an equivalent of the undecomposed hydrate. 



Sericate of Barytes. — This salt may be prepared from seri- 

 cate of potash, by adding an alcoholic solution of the latter 

 to a pure salt of barytes. A bulky white precipitate is thus 

 obtained, which must be thrown on a filter, and well washed. 

 It is slightly soluble both in water and in alcohol; in the 

 former it possesses nearly the same degree of solubility as 

 gypsum. 



I. 0*797 gramme of the salt left, after ignition, 0*266 gramme 

 carbonate of barytes; and 0*858 gramme, burned with chro- 

 mate of lead, yielded 0-691 gramme water, and 1*702 gramme 

 carbonic acid. 



II. 0*4-81 gramme of the salt left, after ignition, 0*161 gramme 

 carbonate of barytes ; and 0*319 gramme, burned with oxide 

 of copper, yielded 0257 gramme water, and 0*634 gramme 

 carbonic acid. 



100-00 100-00 3734-00 100-00 



The absolute quantity of carbon obtained in the analysis 

 was under that slated: in the first 54-85 is the quantity shown 

 by the analysis, but 2-06 per cent, must be added for the car- 

 bonic acid retained by 25*89 of barytes, as carbonate of ba- 



* Amialen der Chemie und Fharmacie, xxxv. 1. 



