Apr. IS, 1919 Meat Extracts, their Composition and Identification 



15 



MOI.ISCH TEST 



By determining the total creatinin content of an extract, the water 

 content being known, it can be definitely classified as either a true-meat 

 extract or as an extract of liver or spleen, and further, an extract identified 

 as having been prepared from either livers or spleens may be further 

 classified as either a spleen or a liver extract, depending upon the reaction 

 in the acetic-acid test. While the identity of a liver extract may thus be 

 established, qualitative tests confirmatory of the conclusions arrived at 

 through the quantitative examination were applied. A reaction based 

 on the occurrence in liver extracts of comparatively large amounts of 

 carbohydrates was suggested and the Molisch test was employed. 



Method of using Moi^isch test. — One cc. of a 10 per cent solution 

 of solid or of a 20 per cent solution of fluid extract was placed in a grad- 

 uated glass-stoppered cylinder of 25 cc. capacity, 9 cc. of concentrated 

 sulphuric acid were allowed to flow gently down the sides of the cylinder, 

 and 6 to 10 drops of a 20 per cent alcoholic solution of alphanaphthol 

 were then added. The stopper was inserted, and the contents of the 

 cylinder were thoroughly mixed. In the presence of carbohydrates a 

 persistent and intense reddish-purple to deep-violet color developed 

 immediately. 



In the initial tests the color of the mixture in the cylinder was noted 

 one minute after shaking, and the contents of the cylinder were then 

 poured into 200 cc. of water, the color again being observed. It was 

 later found that a more satisfactory color test was obtained when the 

 mixture in the cylinder was allowed to stand overnight and observed 

 directly. 



Extracts of knovv'n origin were tested with the results given in Table 

 VI. 



Table VI. — Results of Molisch test of meat extracts of known origin 



"In cases marked "no color" there was no trace of the characteristic purple-red color, but there was 

 usually a greenish-brown color. 



