88 RICHMOND AND MUSGKAVK. 



such variation in the percentages of the important ingredients of an 

 established food stuff are well worth inquiry. In the interest of fairness 

 to the manufacturers and ourselves, therefore, we determined to make 

 a personal examination of the product as found on the Manila market. 



It has been known for some time that Adam's Soxlilett extraction 

 method for the estimation of fats failed in the presence of considerable 

 quantities of carbohydrates and that some other method of procedure was 

 necessary in order to obtain a maximum yield of fat in sweetened con- 

 densed milks, milk powders and malted milks, ilodifications of the 

 Soxhlett method such as drying a highly diluted aqueous solution of the 

 material on large surfaces, interstratifying the dried powder with some 

 inert substance such as sand or asbestos or finely grinding the dried powder 

 with powdered glass, before extraction with organic solvents, will increase 

 the yield somewhat. The percentage of fat in Horlick's malted milk 

 determined in this laboratory both before and after grinding the dried 

 powder with powdered glass was 1.78 and 2.50 per cent respectively. The 

 well-known Babcock volumetric method is also not suitable for such 

 products because of the charring action of concentrated sulphuric acid 

 on the carbohydrates. Leach's " modification of the Babcock process, 

 which consists in separating the sugars from the fats and proteids by 

 means of copper sulphate before the addition of sulphuric acid, is not 

 very satisfactory when applied to malted milks because of the difficidty 

 of accurately sampling the material and in reading the volume of fat 

 obtained. 



Several trials on Horlick's malted milk with Leach's modification of the 

 Babcock process gave an average of 8.33 per cent of fat. 



Cochran,'' with a modified Babcock bottle and by the use of equal 

 volumes of 80 per cent acetic acid and concentrated sulphuric acid, claims 

 that the charring action is much less than when concentrated sulphuric 

 acid is used alone. Instead of centrifugating he separates the fat by means 

 of ether, which is evaporated before the volume of fat is taken. Here 

 again the same difficulties in introducing a very hygroscopic powder into 

 the narrow-neck flask and in reading the correct volimie of fat are 

 encountered. However, it is only fair to state that our attempts to obtain 

 concordant results with Cochran's method were made with the ordinary 

 Babcock bottle which does not provide for sufficient means of escape of 

 the ether vapor. In this laboratory much better results were obtained 

 by precipitating the proteids in malted milk with acetic acid and heat 

 and by subsequent extraction of the dry precipitate with petroleum ether. 



Our exact procedure was as follows: A 1-grani sample of the air-dry 

 powder was transfer ed to a small breaker, 25 cubic centimeters of water 

 added and the whole stirred to a completely homogeneous solution. It 



'Jour. Am. Chem. Soc. (1900), 22, 589. 

 -Jour. Am. Chem. Soc. (1905), 27, 906. 



