THE LIVER. 163 



same time (LEYDEN). This distinction, however, cannot be main- 

 tained. It is certainly true that the presence of more than traces 

 of bile-acids in the urine indicates the existence of hepatogenic 

 icterus; but cases of absorption icterus undoubtedly occur in which 

 no bile-acids can be detected in the urine. 



It has been clearly demonstrated by the above-mentioned obser- 

 vations of MI^KOWSKI and NAUNYN on geese with extirpated 

 livers that the bile-pigments are formed in the liver in arseni- 

 uretted hydrogen icterus. It has also been demonstrated by STADEL- 

 MANN and AFAXASSIEW that the icterus, after poisoning by arseni- 

 uretted hydrogen or by toluylendiamin, must be considered as an 

 absorption icterus. Perhaps the icterus depends in these cases 

 upon the fact that the viscosity of the abundantly-secreted bile may 

 form a check to its outflow, which counteracts the low secretion 

 pressure, so that a stowing and absorption occurs (polycholic 

 icterus). It is also possible that other cases of so-called haematogenic 

 icterus may be of an analogous kind, and that every icterus is 

 consequently hepatogenic. The occurrence of haematogenic icterus 

 cannot be considered as proved beyond doubt, and it is questioned 

 by several recent investigators. 



Appendix to the Bile. Bile Concretions. 



The concrements which occur in the gall-bladder vary consider- 

 ably in size, form, and number, and are of three kinds, depending 

 upon the kind and nature of the bodies forming their chief mass. 

 One group of gall-stones contains lime-pigment as chief constituent, 

 the other cholesterin, and the third calcium carbonate and phos- 

 phate. The concrements of the last-mentioned group occur very 

 seldom in man. The so-called cholesterin stones are those which 

 occur most frequently in man, while the lime-pigment stones are 

 not found very often in man, but often in oxen. 



The pigment-stones are generally not large in man, but in oxen 

 and pigs they are sometimes found the size of a walnut or even 

 larger. In most cases they consist chiefly of bilirubin-calcium with 

 little or no biliverdin. Sometimes also small black or greenish 

 black, metallic-looking stones are found, which consist chiefly of 

 bilifuscin along with biliverdin. Iron and copper seem to be reg- 



