248 Mr. W. R. Dunstan and Miss L. E. Boole. 



" fatty " acid passes over, and a further quantity may be obtained 

 by extracting the residue in the flask with ether. The acid was 

 neutralised with ammonia, and the aqueous solution precipitated 

 with calcium chloride. The semi-crystalline precipitate was dis- 

 solved in alcohol and crystallised from this solution. The acid 

 removed from the calcium salt was neutralised with ammonia, and 

 the aqueous solution of the ammonium salt precipitated by silver 

 nitrate. The white voluminous precipitate was dried, and the silver 

 estimated. Another portion of the precipitate was dissolved in boil- 

 ing alcohol, and the crystals that separated from the solution were 

 also analysed, with the object of determining whether the silver salt 

 was a single substance or a mixture. The percentage of silver in 

 the original silver salt was 30*5, whilst that in the salt crystallised 

 from alcohol was 31*1. The acid, regenerated from this silver salt, 

 crystallised from dilute alcohol, and melted at a low temperature. 

 In order to further characterise this acid a fresh quantity of the 

 silver salt was crystallised and burned with the following results : — 



Weight of salt 0-1169 



Weight of water 0-0831 



Weight of carbon dioxide . . 0'212 



Weight of silver 0'0360 



C = 49*4 per cent. 

 H = 7-89 „ 

 Ag = 30-79 „ 



These results indicate that the acid is one of the higher members 

 of the acetic series, probably either palmitic or myristic acid. The 

 percentages of silver, calculated from the formulae of the silver salts 

 of these acids, are, for silver palmitate, 30 per cent., and silver 

 myristate, 32 per cent. The percentage of carbon found is however 

 too low for palmitic acid, but approximates to that contained in 

 myristic acid. The question as to which member of the series the 

 acid corresponds with can however only be decided by further 

 experiments with larger quantities than we were able to command. 

 Although a fatty acid is produced when alkalis act on the resin, we 

 could find no evidence of the production of glycerine. It may be 

 concluded, therefore, that the resin is not a glyceride, as was prob- 

 able from the mode in which it was isolated. When warmed with 

 strong nitric acid croton resin undergoes oxidation without forming 

 any nitro-compound. A number of acids are produced in this change 

 of which only a preliminary examination has been made. There are 

 at least two fatty acids formed, one of which closely resembles 

 palmitic acid, as well as valerianic acid and oxalic acid. 



The hydrolytic and oxidation products of the resin make it quite 



