DETECTION OF STERILISED MILK. 



197 



It must be lemembeied, however, that no sharp distinction 

 can be drawn between milk which has been raised to a tempera- 

 ture over 7U^ C. for a short period, and which is naturally not 

 sterilised in the true sense of the term, and the milk which has 

 been heated for a sufficient length of time to destroy all microbial 

 life. For this reason, a milk should not be reported as sterilised, 

 solely on the result of a very low percentage of albumin, if neither 

 the " creamometer " nor the para-phenylene-diamine nor " milk- 

 sugar " tests give corroborative indications. It is probable that 

 the milk, in this case, has been pasteurised slightly above 70' C. 



The following figures (Table XLVIII.) by C. H. Stewart show 

 the percentage of albumin found in milk raised to various tem- 

 peratures : — 



TABLE XLVIII. — PePvCe.xtaoe of Albumin in Milk at 

 Various Temperatures. 



30 



HI 

 ,'!(l 



III 

 .(I 



10 



■Si I 

 10 

 ■Ml 



L' 



The following analyses (Table XLIX.) will show to what 

 extent the methods above described can be depended on : — 



TABLE XLIX.— Comparative Analyses of Mixed Fresh 



AND .StERILISEH MiLKS. 



