ANALYSIS OF BUTTER-FAT. 39 



predecessors, belongs to the great class of "doubtful" ones, 

 and like them has never been acknowledged to possess any 

 real value. 



In short, an almost total darkness about the composition 

 of butter-fat existed, due, in our opinion, for the most part, 

 to the misleading analysis of Bromeis, quoted in Chapter I., 

 and to be found in all chemical works. This analysis set 

 forth that butter-fat contained 2 per cent, of butyrin and 

 glycerides of other volatile acids ; calculated as butyrin only, 

 this number represents 1*74 per cent, of butyric acid, 

 C 4 H 8 2 since 302 parts of the butyrin yield 264 parts of the 

 acid. We have also shown that Bromeis's analysis has been 

 found to be incorrect in several most important items. Thus 

 the substance termed by him " margarin " was proved to 

 contain volatile acids, and hence the 1*74 per cent, could 

 evidently not accurately represent the proportion of thes^e 

 acids in butter-fat. Yet, as the presence of volatile acids, 

 such as butyric, caproic, caprylic, and capric acids, was justly 

 considered to distinguish butter from other animal fats, it 

 seemed to be evident that, upon the apparently very trifling 

 quantity of such acids, no test could safely be based by which 

 butter could be with certainty discriminated from other fats. 

 !N"o further steps, therefore, were taken in that direction, as 

 it appeared a hopeless task to look to the volatile acids 

 as foundation of any method ; and detection of fatty adulte- 

 rants by chemical means appeared indeed to be impossible. 



Hence it cannot be wondered at that the attention of 

 chemists was more specially directed towards the physical 

 properties of the various fats, and that the methods proposed 

 from time to time were chiefly founded upon these. We 

 will not, however, enumerate and describe them, as they one 

 and all have proved abortive, and are abandoned except by 

 those few who prefer the old system of butter analysis to 

 methods of acknowledged accuracy and trustworthiness. 



