Vol. VI, No. 4.] The Butter-fat of the Indian Buffalo. 183 



[N.S.] 



examined in the same way, and also gave a curve corresponding 

 almost exactly with that for butyric acid alone (Diagram 3). 

 This difficulty was finally cleared up. If we take a sample of 

 goat-fat and saponify, and then acidify with sulphuric acid and 

 distil, we find that the distillate is neutral, showing the absence 

 of volatile fatty acids in goat- fat. If we add a definite quantity 

 of a mixture of butyric and caproic acids (2:1) before dis- 

 tillation, then fractionally distil and titrate, we get a curve 

 corresponding to butyric acid alone and not to the mixture 

 actually taken (Diagram 3). It appears that the presence of 

 such acids as palmitic, stearic and oleic in the distillation mix- 

 ture lower the curve. 



It was, therefore, necessary in the examination of a sample 

 of butter-fat first to distil over all the volatile fatty acids 

 and then fractionally redistil and titrate. In this way the fol- 

 lowing curves (Diaj 



ram 



ach 



the ratio of butyric to caproic acids is practically 2:1. 



Examination of the volatile fatty acids by Thorp's Process 

 This is a comparatively recent process invented to distin* 

 guish between real butter-fat and margarine containing cocoa- 

 nut-oil, depending on the different relative proportions of the 

 volatile fatty acids in butter-fat and cocoanut-oil. For a des- 

 cription see J.C.S. 1906, abs. ii, 588. Indian buffalo butter-fat 

 gave by this process figures much the same as Thorp obtained 

 for European cow butter-fat. 



Description of butter-fat. 



Titration value 

 of 2nd distil- 

 late in cc. 



N 



JO 



KOH. 



Titration value of 

 insol. volatile 

 acids in cc. 

 N 



10 



KOH 



Fresh butter-fat 



17-1-07 



24 



5-65 



European cow (Thorp) 



• « 



2-i.l— 4 



,V2— 8-4 



Examination of the volatile fatty acids by Kirschner's Pro- 

 cess. — This is another comparatively new process invented for 

 the same purpose as Thorp's. For details see J.C.S. , 1905, 

 abs. IT. 213. Again by this process the volatile fatty acids 

 seemed to be present in Indian buffalo butter-fat in much the 

 same proportion as in the case of the European cow. 



