QUANTITY OF BILE. 205 



however, been asserted that sulphur, and therefore taurocholic acid, does 

 not exist in the bile of the hog. 



The bile is secreted more slowly during a long period of fasting, and 

 more rapidly during normal nutrition. To a certain extent, production of 

 this variable rate depends on the general principle that a bile - 

 gland acts more energetically in proportion as the supply of blood sent 

 to it is greater. If not wanted for the present purpose, the product is 

 stored up, for a time, in the gall-bladder. 



When the bile has been long retained in the gall-bladder, it becomes 

 concentrated through the removal of a portion of its water : change of bile 

 it also undergoes a change of color. In animals whose he- after retention, 

 patic bile is yellow or brown, the cystic bile has a tendency to green, a 

 change of color dependent on partial oxidation, occasioned by the arte- 

 rial blood. 



The flow of bile takes place with different degrees of rapidity at dif- 

 ferent diurnal periods : thus it reaches its maximum in from p eriod of max 

 thirteen to fifteen hours after the last full meal, and then imum flow of 

 rapidly diminishes. 



Bidder and Schmidt estimate the diurnal secretion in an adult at 54 

 oz., containing 5 per cent, of solid matter, an estimate which is undoubt- 

 edly too high, so far as an average diet and state of health are implied. 

 It is asserted that a diet of flesh tends to produce more bile than one of 

 a purely amylaceous kind. Even the use of a large quantity of water 

 increases its amount, and this as regards its solid constituents. Reme- 

 dial agents act in various ways. Calomel increases the fluid, but di- 

 minishes the solid constituents. Carbonate of soda diminishes both. 

 Again, there are great variations in the rate of its production: the circum- 

 stance just mentioned, that its maximum flow is several hours after the 

 maximum digestion, is important as regards the explanation of its forma- 

 tion, showing significantly that it is not directly produced from matters 

 recently absorbed from the intestine, but from the systemic venous blood. 



But the liver has other duties to discharge besides the separation of 

 bile. It gives origin to sugar and fat, as is proved by the Other duties of 

 circumstance that the blood of the hepatic veins is richer in 

 those ingredients than the blood of the portal. In this re- ing bile, 

 spect its action seems more particularly to be that it converts other sug- 

 ars into the particular form known as liver-sugar, which it can also pro- 

 duce from the transforming albuminous bodies ; it forms fat from sugar, 

 and makes from certain other fats the special one known as liver-fat. In 

 this duty of forming sugar and fat, it exhibits an inverse power of action ; 

 as the production of the one predominates, that of the other declines. 



From the .point of view which we have now reached through this de- 

 scription, we are able to see the double duty which this great gland dis- 



