218 The Philippine Journal of Science 1920 
ANALYSIS OF SYNTHETIC MILK 
For the purpose of determining which of the three methods 
will give the most accurate results, analyses were made of “syn- 
thetic” milk, which was prepared in the laboratory by mixing: 
Per cent. 
Water 87.75 
Fat (in the form of butter) 3.40 
Protein (in the form of casein) 3.50 
Pure lactose 4.60 
Mineral substances from the ash of canned milk 0.75 
The results are shown in Table 4. 
- Taste 4.—Analyses of synthetic milk. 
Lactose. 
Sample No. 5 ‘ 
Polaris- | Quisum- , 
copie bing’s Soxhlet’s 
method. | method. | ™ethod. 
' 
Per cent.|Per cent.|Per cent. 
Ts eb bage ea eae ccd, ce u ease eos au pee wks 4.24 4,78 4.80 
8 eicsecccas EEE climes Ree NOR 4,16 4.77 4.80 
Per osttt.of Inctoee agded aio a eas ete ee 4.60 4.60 4,60 
DISCUSSION OF RESULTS 
Table 2 gives the milligrams of lactose corresponding to the 
number of cubic centimeters of 0.1 N potassium permanganate 
solution used in the determination as described. Table 3 shows 
the results of the analysis of the different samples of milk by 
the three methods. Table 4 gives the results with synthetic 
milk with a known percentage of lactose. From these tables 
it may be seen that the percentage of milk sugar given by the 
optical method is consistently lower than by the Quisumbing 
or the Soxhlet method, and also that the Quisumbing method 
gave lower results than did the Soxhlet. The differences be- 
tween the polariscopic method and the two oxidation methods 
are in most cases serious, whereas the oxidation methods may 
be considered to agree closely. The differences between the 
polariscopic method and the two oxidation methods are greater 
in the case of the sterilized evaporated milk than in that of the 
sterilized natural milk or the fresh cows’ milk (see Table 3). It 
was thought that the differences might be due to changes in the 
sterilized evaporated milk that occur during manufacture but 
which do not occur in the sterilized natural milk or in the fresh 
cows’ milk, and that such changes resulted in the formation of 
