PRODUCTION OF SUGAR IN THE LIVER. 465 



described. The whole operation occupied twenty-two seconds. Only ten seconds elapsed 

 from the time the portion of the liver was cut off until it was in the boiling water. It 

 was boiled for about fifteen minutes, made into a paste with animal charcoal, and thrown 

 upon a filter. The clear fluid that passed through was tested for sugar by Trommer's 

 test. There was no marked evidence of sugar. 



Experiment III. A large dog, full-grown and fed regularly every day, but not in diges- 

 tion at the time of the experiment, was held firmly upon the table. This dog had been 

 in the laboratory about a week and was in a perfectly normal condition. The abdominal 

 cavity was opened, and a piece of the liver was cut off and thrown into boiling water, 

 the time occupied in the process being ten seconds. Before the liver was cut up into the 

 boiling water, the blood was rinsed off in cold water. The liver was boiled for about 

 seventeen minutes, mixed with animal charcoal, and the whole was thrown upon a filter. 



Immediately after cutting off a portion of the liver and throwing it into boiling water, 

 the medulla oblongata was broken up, a ligature was applied to the ascending vena cava 

 just above the renal veins, the chest was opened, and a ligature was applied to the vena 

 cava just above the opening of the hepatic veins. A specimen of blood was then taken 

 from the hepatic veins. This portion of the operation occupied not more than one minute. 

 A little water was added to the blood, which was boiled briskly, mixed with animal char- 

 coal, and thrown upon a filter. The liquid that passed through from both specimens was 

 perfectly clear. 



While the filtration was going on, Fehling's test-liquid was made up, so as to be 

 perfectly fresh. The two liquids were then carefully tested for sugar. The extract of 

 the liver presented not the slightest trace of sugar. The extract from the blood of the 

 hepatic veins presented a well-marked deposit of the oxide of copper, revealing unequivo- 

 cally the presence of a small quantity of sugar. 



Experiment IV. This experiment was made upon a medium-sized dog, in full diges- 

 tion of meat. The medulla oblongata was broken up ; the portal vein was tied through 

 a small opening in the abdomen ; and the abdomen was then widely opened, and a por- 

 tion of the liver excised, rapidly rinsed, and cut up into boiling water. The length of 

 time that elapsed between breaking up the medulla and cutting up the specimen of liver 

 into the boiling water was one minute. 



The vena cava was then tied above the renal veins, the chest opened, and the cava 

 again tied above the hepatic veins. Blood was then taken from the hepatic veins, about 

 an equal bulk of water was added, with an excess of the crystallized sulphate of soda, and 

 the mixture was boiled. A portion of the portal blood and the decoction of the liver 

 were then treated in the same way, and the three specimens were filtered. 



The clear extracts were then tested with Fehling's liquid, with the following result : 



There was no sugar in the portal blood. 



There was no sugar in the extract of the liver. 



There was a marked reaction in the extract of the blood from the hepatic veins, the 

 precipitate rendering the whole solution bright yellow and entirely opaque. 



This experiment was made in the presence of the class at the Bellevue Hospital Med- 

 ical College, January 4, 1869. 



The importance of the question under consideration and its present unsettled condi- 

 tion are, we hope, sufficient to justify the introduction of the details of the preceding 

 experiments. They were undertaken with the view of harmonizing, if possible, the facts 

 brought forward by different experimentalists. 



It is difficult to imagine how any observer, so well known and accurate as Dr. Pavy, 

 could assert positively, as the result of personal examination, that the liver does not 

 contain sugar when examined immediately after its removal from the living body, when 

 Bernard and so many others have demonstrated its presence in this organ in large quantity. 

 Yet, such was the result of all the experiments of Pavy, and the same conclusion was ar- 

 rived at by M'Donnell, and afterward by Meissner and Jaeger, and by Schiff. The ingenious 

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