138 



EXPERIMENT STATION. 



[Jan. 



should, of course, be avoided. As to the specific action of air, 

 light and moisture, the experiment should be considered only 

 preliminary, pointing the way for further work under '' control " 

 conditions. 



Action of Heat. 



The object of the second experiment was to ascertain what 

 changes might take place upon heating butter fat several days 

 at 50° C. Fresh samples were prepared. After heating a 

 sample twenty-four hours in a water bath, varying amounts were 

 weighed for saponificaticm, acid and iodine numbers ; similar 

 portions were withdrawn at the end of forty-eight hours, and 

 again after seventy-two hours' heating. 



The analysis of the check sample and of the heated fat are 

 presented in the following table : — 



The results indicate a slight difference between the two 

 samples in spite of careful mixing, as shown by the saponifica- 

 tion and acid numbers. Heating gave a very slight increase in 

 acid number, otherwise no change is noticeable. It seems evi- 

 dent, therefore, that any reasonable heating of butter fat at a 

 temperature not exceeding 50° G. would have little aiipreciable 

 effect upon analytical results. 



