lO-i T>v. L. Play fair on a netv Fat Acid 



rent and highly crystalline. Its melting point is between 

 4.8i° and 49° C. 



The atomic weight of the anhydrous acid obtained by the 

 analysis of the salt of silver, is 2733 "27 ; the mean of two 

 analyses of the salt ofbarytes gave the atomic weight 2732*54. 

 The formula of the anhydrous acid deduced from the analyses 



of its salts is Coy Hoy Og. 



The formula for oenanthic acid is C,4 H,3 O.^; sericic acid 

 may, therefore, be considered to have the same composition 

 as oenanthic acid, in which one equivalent of oxygen is re- 

 placed by one of hydrogen. 



2 atoms of oenanthic acid = C^g Hog O4 

 1 atom of sericic acid = Cog H07 O3 



It may be compared, in this respect, to benzoic acid and the 

 hydruret of benzule. 



The anhydrous acid has not been procured in an isolated 

 state ; the acid procured by the decomposition of sericate of 

 potash b}"^ muriatic acid, is the hydrate, and contains one 

 atom of water. The following are the results of the analyses 

 of this hydrate. 



I. 0'35l gramme of substance, burned with oxide of 

 copper, gave 0*389 gramme water, and 0*94 1 gramme car- 

 bonic acid. 



II. 0*309 gramme of substance gave 0*342 water, and 0*829 

 carbonic acid. 



III. 0*412 gramme of substance, burned with chromate of 

 lead, gave 1*101 carbonic acid, and 0*454 water. 



IV. 0*250 gramme of substance gave 0-670 carbonic acid, 

 and 0*276 water. 



V. 0'278 gramme of substance gave 0*744 carbonic acid, 

 and 0*309 water. 



These numbers approach closely to the formula Cog Hgg O4 

 Atoms. In 100 parts. 



28 Carbon 2140*18 74*06 



28 Hydrogen... 349*42 12-09 



4 Oxygen 400*00 13*85 



2889-60 100-00 



♦ The analyses Nos. i. 11. iv. were made upon sericic acid repeatedly 

 crystallized from alcohol ; iv. was kindly executed by ^h•. Miller, assistant 

 to Professor Daniell; in. v. were made upon the acid obtained by decom- 

 posing sericate of soda with muriatic acid, with precautions formerly de- 

 scribed. 



1 



