GLYCOGEN AND GLUCOSE IN THE LIVER. 235 



only the glucose present in the organ at the moment of death, but also 

 that which accumulates afterward. The proportion found in the dog at 

 the end of twelve hours corresponds very closely in both tables. 



It has been doubted by some observers (Pavy, Meissner, Hitter, 

 SchifF), whether glucose be really produced in the liver during life ; its 

 presence in the liver tissue, in ordinary examinations, being attributed 

 entirely to a post-mortem production by transformation of the glycogen. 

 It is true, as these experimenters have found, that if a small portion of 

 the liver substance be cut out from the body of the living animal and 

 instantly plunged into a freezing mixture, boiling water, or strong 

 alcohol, so as to arrest the transformation of the glycogen, its subse- 

 quent examination may not show the presence of glucose by Trom- 

 mer's test, as applied in the usual way. Professor Flint, Jr., 1 by ope- 

 rating in this way with boiling water, found in two instances, where 

 the time employed in the extraction and coagulation of the liver sub- 

 stance was respectively 28 seconds and 22 seconds, there was no marked 

 or certain evidence of sugar. In another instance, where the time em- 

 ployed was only 10 seconds, the liver extract presented no trace of 

 sugar whatever; and yet the blood of the hepatic vein, obtained within 

 a minute after the first operation, showed a well-marked saccharine reac- 

 tion by the copper test. We have also found, that under similar con- 

 ditions, the liver tissue may yield no reduction by the copper test at the 

 end of 17 or of 22 seconds, though it is distinct in 50 seconds after its 

 extraction from the living body. Harley, 2 by killing the animal by 

 section of the medulla oblongata, immediately placing a portion of the 

 liver in a freezing mixture and afterward slicing it directly into boiling 

 acidulated water, has shown that glucose may be demonstrated to exist 

 in the organ within 20 seconds after the death of the animal. 



But the failure to demonstrate the presence of glucose, even within 

 the shortest time after the extraction of the liver, is only owing to the 

 use of too small a quantity of the liver tissue and an imperfect purifica- 

 tion of its watery extract. If these sources of error be avoided, glucose 

 will always be found in the liver at the instant of its extraction, or as 

 soon afterward as the necessary test can be applied. In order to demon- 

 strate this, a portion of the liver is to be taken out of the abdomen of 

 the living animal by an instantaneous incision, reduced to a pulpy mass 

 by passing it between two fluted rollers, and at once dropped into a 

 vessel of boiling water or of strong alcohol. By this means all further 

 change of the glycogen is arrested, and the time which elapses between 

 the extraction of the liver substance and its immersion in the coagulating 

 liquid may be reduced to a very few seconds. A watery extract is finally 

 to be made of the liver substance, which must be completely purified by 

 the repeated use of animal charcoal until it is absolutely transparent 



1 New York Medical Journal, January, 1869. 



2 Proceedings of the Royal Society of London, vol. x. p. 289. 



