ESTIMATION OF FAT IN FOOD FOR INFANTS. 471 
placed in a cylinder and mixed with 10 cc. water. The 
contents of the cylinder were washed on to filter paper, 
previously extracted with ether. The water was driven 
offat 90° O. The washing of the traces of undissolved food 
from the cylinder was a tedious process which occupied 
about two days. The dried filter paper was extracted with 
dry ether in a Soxhlet apparatus. The filter paper was 
redried and the extraction repeated. The results are 
recorded in Table III. 
Table ITI. . 
No. Weight of Food in gm. | Weight of Fat in gm. Percentage of Fat. 
l 0:7457 | 0-1310 17:5 
2 1°4785 | 0-2152 14:5 
3 4-368 0:3635 8:3 
It will be seen that the fat is completely extracted when 
the quantity of food is less than 750 mg. Similar results: 
were obtained by repeating the experiment. An attempt 
to vary the method by mixing the food with glass wool, 
moistening with water and drying, yielded only 9.87% of 
fat. The saponification number of the fat obtained by this 
method was 232. The fats obtained were thus all butter 
fats. 
To elucidate the failure of the extraction by ether per- 
formed in the usual manner, two other foods for infants 
made by the same firm were subjected to analysis. Both 
these foods gave the same figures for fats by extraction 
with ether and by the process of Rose and Gottlieb. 
The results are recorded in Table IV. 
Tablesty 
No, Percentage of Fat on extraction. Percentage of Fat, Rése-Gottlieb. 
1 ars | 5:4 
2 6°73 6°6 
