ABSORPTION. 207 



organ usually contains a store of glycogen derived from the last diges- 

 tive process, the conversion of this substance into glucose will go on after 

 death, and even in the separated liver, at the temperature of 38 C. 

 If the liver of a healthy dog be taken out immediately after death and 

 injected with water by the portal vein, the fluid which escapes by the 

 hepatic vein, after traversing the liver tissue, contains sugar. But as 

 the injection is continued, the quantity of glucose extracted by it from 

 the liver grows constantly less ; until in from half an hour to an hour 

 it is completely exhausted, and neither the injected fluid nor the hepatic 

 tissue contains any further trace of glucose. If such a liver be kept in 

 a moderately warm place for some hours its tissue will again become 

 saccharine. Its glucose may be exhausted by a fresh injection, and again 

 reproduced until all the glycogen has been transformed, or until decom- 

 position begins to be established. The glycogen, being less soluble than 

 sugar, remains behind after such an injection and produces a new supply 

 of glucose by a new transformation. 



After death, accordingly, if the liver be allowed to remain saturated 

 with its natural juices, this transformation goes on for a time, and the 

 glucose of the hepatic tissue increases at the expense of its glycogen. 

 This fact is established by the experience of all observers. According 

 to our own observations on the dog, the glucose in the liver is increased 

 within an hour after death to four or five times its former quantity. 

 Afterward the change goes on more slowly, its rate diminishing with 

 the lapse of time, so that at the end of twelve hours the sugar may 

 hardly exceed five or six times its original amount. The following 

 table gives the result of three experiments in this direction : 



PROPORTION OF GLUCOSE IN THE LIVER OF THE DOG AT DIFFERENT PERIODS 



AFTER DEATH. 

 At the end of Per thousand parts. 



C 5 seconds 810 



Xo. 1. -' 15 minutes 792 



I 1 hour 10.260 



No { 5 seconds ' 3 - 850 



1 6 hours 11.458 



4 seconds 2.675 



T^J. t 1 hour 11.888 



' 4 hours 13.361 



12 hours 15.351 



It has been denied by some writers (Pavy, Meissner, Ritter, Schiff) 

 that glucose exists in the liver during life ; the whole of it being con- 

 sidered as the product of a change after death. But there is abundant 

 evidence of its existence at the moment of death, or when pieces of the 

 hepatic substance are excised from the living animal ; and even its 

 quantity under these circumstances is nearly uniform, varying from 

 about 2 to 4 parts per thousand of the liver tissue. Harley,* who 



* Proceedings of the Eoval Society of London, 1860, vol. x., p. 289. 



