14 



Journal of Agricultural Research 



Vol. XVII, No. I 



With spleen extracts only was a decided precipitate obtained. The 

 precipitate was very bulky and yellowish white in color, easily distin- 

 guishable from both the slight, dark precipitate yielded by the liver ex- 

 tracts and the slight precipitate obtained with the corned-beef cook liquor. 



Mixtures of varying amounts of hog spleens (No. ii) and chuck and 

 plate extract (No. 19) were prepared and tested with acetic acid in the 

 manner shown above, in order to determine the delicacy of the reaction. 

 A precipitate was obtained in mixtures containing 5 per cent of spleen 

 extract, but the reaction was faint, and it was not until the mixed extract 

 contained a quantity approximating 20 per cent that a decided reaction 

 was obtained. 



Since the above tests were made an extract has been received and 

 examined under the meat-inspection regulations which gave a positive 

 reaction with the acetic-acid test, although not resembling spleen extracts 

 in other respects. 



An investigation by the field service of the Meat Inspection Division 

 disclosed that this extract was prepared from bones through long-con- 

 tinued extraction with boiling water. Inasmuch as bone extract 

 previously examined had not given the reaction, a laboratory investiga- 

 tion of this unusual feature was made, three bone extracts being pre- 

 pared by extraction with boiling water for at least three hours. Upon 

 testing the finished products the reaction, which heretofore had been 

 limited to spleen extracts, was obtained. The precipitate from both 

 the spleen and these bone extracts appeared to be a mucin. From the 

 standpoint of the food analyst the value of the test, however, is not 

 lessened, as the diflferentiation of bone extracts from other extracts, 

 including spleen, is readily made, which may be noted by comparing 

 the analyses given in Table V with those of other extracts previously 

 tabulated (see Table II). 



Table V. — Analyses of bone extracts 



Constituent. 



Total solids 



Ash 



Sodium chlorid 



Phosphorus pentoxid (total) 



Nitrogen 



Tannic-acid salt filtrate nitrogen 

 Zinc-sulphate filtrate nitrogen . . 



Total creatinin 



Acetic-acid test 



Molisch test 



Per cent. 



57-54 



3-42 



.81 



.29 



8.54 



.35 



3-23 



None. 



Positive. 



Negative. 



Extract 



°er cent. 



62. 90 



13. 80 



7-58 



.49 



7.90 



1. 46 



2. 21 



None. 



Positive. 



Negative. 



Extract J. 



Per cent. 



63-53 

 14. 81 



7-32 



-59 



10. 40 



1-37 



3.60 



None. 



Positive. 



Negative. 



While not applying to the real purpose of this paper, it may be of 

 interest to note that an extract of bone marrow failed to afford a precipi- 

 tate with acetic acid. ' 



