470 H. G. CHAPMAN. 
for twenty-four hours in the apparatus. Less than one 
milligram of fat was recovered. Later an extraction was. 
made in a similar way of the contents of six different tins. 
The averaged result was 7°247/ of fat, which agrees 
sufficiently with the averaged result of the figures in Table 
die WAG: 
An estimation of the amount of fat extracted by petro- 
leum ether was also made in the same way. The estimation 
gave 6°27% on the first extraction. Redried and extracted 
a second time, less than 0°02% of fat was obtained. 
The fat was estimated also by the Rose-Gottlieb Method.* 
The results are tabulated in Table II. 
Table IT. 
No. Weight of Food in gm. Percentage of Fat. 
1 1:4915 16-67 
2 1°8895 Louie 
3 1°9820 16:9 
4 2:1660 17:0 
5 2:6380 17:0 
The figures show an averaged result of 16°857%. This 
figure is more than twice that obtained by the ordinarily 
employed method of extraction. 
In order to determine whether the fats extracted by the 
two methods were identical, their saponification numbers 
were determined by Koettstorfer’s process. The numbers ° 
obtained were 234 and 236 respectively. Both samples of 
fat contained a trace of nitrogen (under 0°1%) and yielded 
no weighable amount of ash on incineration. 
To confirm the figures obtained by the wet process of 
Rose and Gottlieb, a weighed quantity of infants’ food was 
1 Aberhalden, Arbeitsmethoden, Bd v., Abt. 1, 8. 432, Berlin u. Wien, 
1911. , 
