94 BILE. 



as, for instance, by potash and nitre, we find that the residue of the 

 portal blood is certainly the richer in sulphur. On an average, I 

 found 0*393 of sulphur (all the sulphuric acid being calculated as 

 arising from sulphur) in 100 parts of the solid residue of portal blood, 

 and 0*331 of sulphur in 100 parts of that of hepatic venous blood. 

 The sulphur which is applied to the formation of this adjunct is 

 therefore as latent (unoxidised) or combined in the portal blood, as 

 in the adjunct itself. It now remains for us to enquire to what 

 substance does it owe its origin ? 



In the spirituous extract of portal blood (after the residue has 

 been already extracted with ether and alcohol) I found a substance 

 which, on incineration with nitre, yields sulphur. (As it can also be 

 obtained when the blood has been previously neutralised, it cannot 

 depend on any albuminate of soda that may have been dissolved 

 by the spirit). Moreover this sulphur-compound is also found in 

 lesser quality in the blood of the hepatic veins. It is possible that 

 the taurine, which, as we know, is rich in sulphur, may be formed 

 from this sulphurous extractive matter. The principal source of 

 the sulphur of the bile, and especially of the taurine, might, how- 

 ever, be sought in the perfect disintegration of the fibrin in the 

 liver. I shall show, when treating of "the blood/ 5 that the 

 quantity of fibrin in hepatic venous blood is almost imperceptibly 

 small, and, indeed, that often Icould discover no fibrin whatever in it. 

 The substance which was calculated as fibrin by Schultz and Simon, 

 in their analyses of the blood of the hepatic veins, could not have 

 really been that substance, but must have been the cell-walls of 

 the blood-corpuscles, deprived of their contents by water. Hence, 

 whether or not the extractive matters contribute to the formation 

 of the nitrogenous and sulphurous adjuncts of the cholic acid, it is 

 by no means improbable that the fibrin of the portal blood is applied 

 in that manner. But there is reason to believe that these adjuncts 

 are primarily formed in the liver, not merely from their absence in 

 portal blood, but also on the following purely chemical ground : we 

 have seen, in the first volume, that glycine and taurine are not to be 

 regarded as existing pre-formed in glycocholic and taurocholic acids ; 

 it is, however, the ordinary rule (and only few exceptions are known 

 to it), that the so-called conjugated compounds are not directly 

 formed from the adjuncts into which they become separated on 

 decomposition ; chemical experience, therefore, renders it impro- 

 bable that these conjugated acids should be formed from pre- 

 existing taurine or glycine and cholic acid. Moreover, we can 

 hardly expect that in the animal organism, where complex com- 

 pounds are resolved into simpler ones (when the retrograde 



