67 



flask heated so that the filter is continually immersed to about one- 

 half its height in condensed ether. The complete extraction of 

 the fat requires from one to two hours' treatment. The ether is 

 then carefully distilled off, the last traces being removed by heat- 

 ing in an air bath at from 100 to 110° C, while the flask is placed 

 into a horizontal position. After cooling in the dessicator, the 

 flask is weighed, the increase corresponding to the amount of 

 fat contained in the quantity of sample taken. 



Determination of the Soluble Carbo- 

 hydrates. 



In the determination of the soluble carbohydrates, it is of im- 

 portance that the directions for use, as established by the manu- 

 facturer, should be carefully considered. The manufacturer's 

 claim in regard to this is fully justified by the fact that more sol- 

 uble carbohydrates are contained in the food after its preparation, 

 according to the directions, than are contained in the food previous 

 to such preparation. The value of an analysis which gives the 

 composition of the food as it is employed, is, likewise, the only 

 guide which a physician has for the determination of the value of 

 a milk-food. 



In the case of milk-foods containing diastase, we take 1 part of 

 milk-food and 10 parts of distilled water, and treat this mixture 

 carefully according to directions. In other respects, the method 

 of analysis is the same as for other milk-foods. 



In the case of ordinary milk-foods, we take for 1 part 10 parts of 

 water, or for from 2 to 3 grms., the ordinary quantity taken, from 20 

 to 30 c.c. water. The mixture is then heated to boiling, and kept 

 boiling for five minutes with continual stirring. It is then allowed 

 to cool. This process should be accelerated by blowing and stirr- 

 ing, to prevent the formation of a skin on the surface. This part 

 of the operation is best carried out in a porcelain or platinum dish, 

 which should be large enough to conveniently hold the double 

 quantity of the fluid used. After cooling, the contents are trans- 

 ferred to a beaker of 150 to 200 c.c. contents, the material adher- 

 ing to the sides of the vessel being carefully washed with 100 c.c. 

 alcohol, of 50° Tr,, into the beaker, so that the sediment therein 

 is not disturbed. The whole is allowed to stand over night. The 

 clear fluid is then first drawn oflE by means of a siphon and filtered 

 through a dry filter. Finally the precipitate is washed on the filter 



