84 



ANALYSIS AND ADULTERATIONS OP BUTTER. 



A bubble, the specific gravity of wMcli was 896', was tested 

 in the fat and sank at 135° F. The indication given is there- 

 fore 896', as against a real specific gravity of 895'2 at 135° F., 

 which corresponds to an error of 2° F. ia temperature of 

 specific gravity bottle at the time of taking the weight. 



Butter-fat was then mixed with lard-fat in the melted 

 ■ state by successive additions of one-sixth of the latter by 

 weight, so that No. 1 is pure lard, No. 2 five-sixths lard, and 

 No. 7 pure butter. 



These mixed fats were each tested with five bubbles of the 

 following gravities at 60° F. : — 



AandB 889-0 



CandD 888-0 



E 896-0 



The following table was given to show the " actual 

 densities" of these fats at- 100° F., and the temperatures at 

 which the bubbles were found by actual experiment to 

 sink ; — 



From these results it is seen that a sample of butter having 

 an actual density of 911-, the beads of specific gravity 889- 



