NORMAL EXCREMENTS. 143 



blackish brown mass, which under the microscope exhibits no 

 trace of crystallization ; no distinct reaction either of the biliary 

 acids (by the sulphuric acid and sugar test) or of bile-pigment (by 

 nitric acid) could be obtained. The watery extract, even when 

 obtained before the substance had been treated with alcohol and 

 ether, contains no substance which is coagulable or precipitable 

 by acetic acid ; it contains, however, a nitrogenous body precipi- 

 table by tannic acid but not by metallic salts ; and it yields no 

 trace of sulphates. 



The bright yellow, semi-fluid excrements of infants at the breast 

 contain, as was shown by Simon,* a very large amount of fat, 

 which may naturally be referred to the milk, besides much 

 coagulated but undigested casein; the alcoholic extract, when 

 treated with a mixture of sulphuric and nitric acid, generally gives 

 the well-known changes of colour indicative of cholepyrrhin ; and 

 Pettenkofer's test applied to this extract usually demonstrates the 

 presence of the biliary acids. Epithelial structures abound in 

 these excrements. 



Liebig some years ago made the remark that the solid excre- 

 ments contain only a small amount of soluble salts; I found only 

 23'067# of soluble salts in the ash of normal human excrement; 

 Fleitmann,t on the other hand, found 30'58-g- (after an abundant 

 animal diet), and PorterJ 31'58-g-; the latter chemist found that in 

 dried normal excrements generally there are contained, on an 

 average, 6'69 of mineral substances. The ash of human faeces 

 contains, according to Fleitmann, 30'98, and, according to Porter, 

 36'03^ of phosphoric acid in combination with alkalies or earths, 

 the acid being combined with three atoms of base; the former 

 found only 1'13 of sulphuric acid, the latter 3'13; it is singular 

 that in the analyses of both these chemists, the potash pre- 

 ponderates in an extraordinary degree over the soda ; if we deduct 

 the chloride of sodium from the soluble constituents of the ash, 

 the ratio of the soda to the potash in the ash is 1 : 40, according to 

 Fleitmann, while it is only 1:12 according to Porter : a difference 

 which depends upon the nature of the food. "Berzelius first 

 directed attention to the fact that more lime than magnesia must 

 be absorbed in the intestine, since we find in the solid excrements 

 less lime and relatively more magnesia than in the food that has 

 been taken; while the ratio of the lime to the magnesia in the 



* Med. Chem. Bd. 2, S. 488 [or Vol. 2, p. 369, of the English translation]. 



* Pogg. Ann. Bd. 76, S. 356. 



$ Ann. d. Ch. u. Pharm. Bd. 71, S. 109-115. 



