190 H. B. TAYLOR. 



Loss in total solids through decomposition. 



The decomposition of milk due to the agency of bacteria 

 is accompanied by a decrease in the percentage of total 

 solids. The total solids were determined by evaporating 

 to dryness 5 grams of milk over a steam bath, and then 

 drying for three hours in a steam oven. The first evidence 

 of a decrease was obtained at the same time as a change 

 in the H ion concentration and acidity was noticed. For 

 milk kept at a temperature of 30° O. the average loss in 

 total solids was *44, corresponding to a percentage loss of 

 3*84 for the original total solids present. 



In the table given below, the figures in the first column 

 represent the percentage of total solids at time hours, 

 those in the second column the value after 24 hours. All 

 the samples were kept in a thermostat at 30° 0., the neck 

 of each bottle being closed with cotton wool. 



Table X. 



V T.S. at t 



% T.S. at t 24 1 



decrease in T.S. 



% Decrease. 



13-09 



12*40 



•69 



5-27 



14*69 



14*51 



•18 



1-23 



13*01 



12*60 



•41 



3-20 



14*16 



13*37 



•79 



5*60 



13*60 



13*20 



•40 



2-93 



14*80 



14*50 



•30 



2*03 



14*16 



13*70 



•46 



3*25 



12-86 



12*33 



•53 



4-17 



13-02 



12*36 



•66 



5*08 



12-35 



11*90 



•45 



3*65 



16*82 



15*03 



•79 



4-70 



12*47 



11-84 



•63 



5*05 



It may be of general interest to see what effect the 

 weather conditions have on the rate at which milk decom- 

 poses (i.e.) how the weather conditions affect the number 

 of bacteria gaining access to the milk. To show this the 



