CHAP. VI.] THE RESEARCHES OF MINKOWSKI AND NAUNYN. 365 



The conciu Stem 2 had shewn that when, in doves, all the blood- 



sive expert- ^vessels going to the liver are tied, as well as the bile- 

 ments of Min- ducts, no bile colouring matter accumulates in the 

 kowski and blood and tissues : a result which absolutely proved the 

 incorrectness of Harley's views that the bile colouring 

 matter, unlike the bile acids, is not formed in, but is merely excreted 

 by the liver. 



In doves, however, the secretion of urine is completely arrested by 

 the ligature of all the vessels supplying the liver, whereas in ducks and 

 geese, as Minkowski and Naunyn discovered, the secretion continues 

 after the operation. Applying the method first employed by Stern 

 to these animals, with the addition that the liver was subsequently 

 extirpated, they found that if the whole of the liver had been 

 removed, the urine remained free from biliary constituents. Having 

 determined that normal ducks and geese after the inhalation of 

 arseniuretted hydrogen excrete bile colouring matters in the urine, 

 they proceeded to expose ducks and geese from which they had 

 removed the liver to the same agent. In the time which intervened 

 between the poisoning and the death of the bird, urine was excreted 

 which contained haemoglobin, but which was free from bile colouring 

 matters. They thus succeeded in demonstrating that in the most 

 typical cases of supposed haamotogenic jaundice, the excretion of 

 bilirubin is necessarily connected with, and dependent on, the liver. 



In a sense, however, these cases of jaundice induced by ictero- 

 genic drugs differ from the ordinary run of cases of jaundice, in that 

 the changes induced in the blood are probably the starting point of 

 the hepatic changes which lead to the subsequent absorption of bile 

 colouring matters and which are the cause of the polycholia which 

 distinguishes them in their earlier stages. 



As was previously stated, some (Ley den 3 , Budd, Harley) who 

 held the opinion that two great divisions of cases of jaundice existed, 

 believed that they could be discriminated one from the other by de- 

 termining whether the urine contained bile acids as well as bile 

 colouring matters, the former being said to be only excreted in jaun- 

 dice from obstruction. As a matter of fact the discovery of bile acids 

 in urine does not admit of being satisfactorily made by the simple 

 employment of Pettenkofer's reaction, and the scientific proof of the 



S:esence of bile acids requires operations of considerable complexity, 

 ut Stadelmann 4 has conclusively proved that, in the jaundice occa- 

 sioned by icterogenic drugs, the urine often contains bile acids as well 

 as colouring matters, whilst Naunyn 5 discovered them in two cases of 



1 See note 6, p. 364. 



2 Hans Stern, ' Beitrage zur Pathologie der Leber und des Icterus. 1. Ueber die 

 normale Bildungsstatte des Gallenfarbstoffes.' Archiv f. exp. Pathol. u. Pharmak. 

 Vol. xix. (1885), pp. 3959. 



3 Leyden, Beitrage zur Pathologie des Icterus. Berlin, 1866. 



4 Stadelmann, op. cit. Archiv f. exp. Path. u. Pharmak. Vol. xvi. p. 221. 



5 Naunyn, ' Beitrage zur Lehre vom Icterus.' Archiv f. Anat. u. Phys. 1868, 

 p. 438 et seq. 



