GENERAL CONCLUSIONS. 569 
Rutherford, Vignal, and Dodds have experimented with a very 
large number of drugs, which were injected, dissolved in bile, into the 
duodenum. 1 The action of certain of these drugs has been re-investi- 
gated by Paschkis 2 and by Lewaschew, 3 whose results do not in all cases 
confirm those of the previous observers. It is, however, unnecessary to 
consider them in. detail. Naunyn 4 sums up the matter by saying, 
" Many substances, when taken into the stomach, and more surely 
still when introduced into the duodenum (Rutherford), appear to pro- 
duce under certain conditions a slight increase of the biliary secretion. 
But the influence of these substances upon the secretion of bile is 
uncertain, and never a potent one." 
General Conclusions. 
From a study of the mechanism of bile secretion, it is manifest that 
in its bile-producing function the liver differs from most other glands, 
since its activity is nut under the direct control of the nervous system, 
but is modified by the ebb and flow of the blood stream, and by the 
influence of various chemical substances, such as the salts of the bile 
acids. 
The relationship of bile secretion to the other functions of the liver 
is in many points still obscure. That the disintegration of haemoglobin 
and the formation of bile pigments are closely connected, is definitely 
known (p. 5G3). That these two functions are connected with the 
production of urea, is shown by the fact that the administration of hsemo- 
lytic agents, such as toluylenediamin, pyrogallic acid, etc, which increase 
the formation of bilirubin, cause a proportionate increase in the dis- 
integration of red blood corpuscles, and in the excretion of urea. 5 
How far the formation of the amido-acids of the bile salts is con- 
nected with the disintegration of proteids, cannot be considered as 
settled, but the evidence adduced on p. 562 suggests that such a 
relationship exists. If this be the case, the formation of biliary con- 
stituents must be connected with the manufacture of glycogen and 
glucose from proteids. The formation of bile seems independent of the 
mere accumulation of carbohydrates in the liver. 
The various compounds of fatty acids in the bile are probably 
derived from the fatty acid compounds stored in the liver (p. 564). 
The nucleo-proteid, the mucin, and the cholesterin are probably to lie 
regarded, not as true biliary constituents, but as products of the bile 
passages. As to the relationship of the inorganic salts of the bile 
with the other hepatic functions, nothing is known. 
1 Rutherford, loc. cit. 2 Loc. cit. z Loc. cit. 
4 "Cholelithiasis," translated by A. E. Garrod, New Syd. Soc, p. 172. 
5 Noel Paton, Brit. Med. Journ., London, 18S6, vol. ii. p. 207. 
