possibility of any change in the blood after removal, a canula with a stopcock was inserted into the carotid artery of the living animal, and the blood as drawn was allowed to flow directly into the boiling acidulated water. This blood on being treated as above, afforded sugar: as also did another specimen after standing 24 hours. For a third experiment, a good-sized dog, fed for four days solely on flesh, was given half a pound of boiled horse-flesh; three hours afterward 1 ounces of blood were drawn from the femoral artery directly into the boiling mixture. This, as well as another portion of blood which had stood 3 hours, was found to contain sugar; and so far as the eye could judge, the amount in each case was equal. Previous experiments having shown that the sugar in arterial blood varied from 0 to 0.24 per cent, Harley considered it unnecessary to estimate it quantitatively in these experiments. The next question is whether glycogen is normally transformed into sugar. For this purpose a fourth experiment was made on a dog, fed on animal food solely for 14 days, and killed four hours after a meal of boiled horse-flesh, by section of the medulla. The abdomen was at once opened, one portion of the liver sliced off and placed in ice and salt, a second portion rinsed, macerated, and examined for sugar, with a positive result. After half an hour the frozen fragment was, without thawing, sliced directly into boiling water containing a few drops of acetic acid. On treatment, as much sugar as before, apparently, was obtained. A third piece of the liver, which had remained for 40 minutes in the abdomen, was much more strongly saccharine. Fifth, a dog fed for ten days on boiled tripe, was pithed 22 hours after eating, and in less than 20 seconds a portion of the liver was in the freezing mixture. A second portion was at once examined for sugar, together with some portal and hepatic blood collected at the same time. While the portal blood contained no sugar, the hepatic blood, and both portions of the liver yielded it; nor did portal blood furnish sugar either after standing all night, or after being mixed with saliva; though the amount in both decoctions of the liver was increased by this treatment. Sixth, a large and vigorous dog, after fasting 72 hours, was pithed, and a portion of the liver placed in ice and salt. Blood was collected from the portal vein, the liver where sliced, the right side of the heart, the aorta, and the inferior vena cava. Except that from the liver, none of these portions contained sugar. That from the right side of the heart was doubtful because most of the hepatic blood escaped from the cut surface, and also because the supply of blood to the liver was stopped by ligation of the portal vein. None of these specimens, moreover, except that from the liver, afforded any glycogen. The

frozen portion of the liver, examined 3 hours afterward, yielded sugar. The seventh experiment was quantitative; a dog, previously fed on meat, received a full meal of bread and milk, and five hours afterward was pithed. A portion of the liver was at once sliced off and placed in a freezing mixture. Some portal blood collected at the same time afforded a small amount of sugar, derived evidently from the food. Two hours afterward a portion of the frozen liver, and a portion of that which had remained warm in the body of the animal, were weighed, and the sugar in each was determined volumetrically. The frozen piece of the liver contained 0.333 per cent of sugar; the other portion afforded 1:55 per cent; showing a five fold increase in 2 hours. But 0.333 per cent is no inconsiderable quantity, since in a human liver weighing 50 ounces, it would amount to seventy grains of sugar. He concludes as follows: 1st, Sugar is a normal constituent of the blood of the general circulation; 2d, Portal blood contains sugar, when the diet is mixed; 3d, On an animal diet, as also when fasting, portal blood is devoid of sugar; 4th, Whatever the diet, the liver of dogs always contains sugar; 5th, Under favorable conditions, sugar exists in the liver of animals after three days fasting; 6th, this sugar comes partly from the food, partly from the liver, when the food is mixed; 7th, The liver of animals on a meat diet, has the power of forming glycogen, which is, at least partly, transformed into sugar ;-it may however be transformed into other matters also; 8th, Since sugar is found in the liver at the moment of death, it cannot be viewed as the result of a post-mortem change, but has an origin strictly physiological.

(59.) In May, R. MCDONNELL published some experiments instituted to ascertain whether the liver converted the amyloid substance into sugar normally during life. For this purpose, he removed blood from the right side of the heart in the living animal, and examined it for sugar. The results were: (1.) In twelve experiments with dogs fed on meat for some weeks previous, traces of sugar were found in the blood of five; none could be detected in the blood of the remaining seven; (2.) In four rabbits, fed on boiled eggs, meat, and butter, for some days, no sugar was detected in the blood drawn from the right side of the heart; (3.) In three dogs, fed on mixed diet, and three rabbits, fed on carrots, potatoes, etc., sugar was found in the blood of the right side of the heart, and in equal quantity in blood from the carotid; (4.) In three rabbits, fed on vegetables, sugar was found in the blood removed from the right side of the heart during life; but double, and in one case more than treble the amount, was found in blood thus taken Dublin Hosp. Gaz., May 15, 1860; Am. J. Med. Sci., II, xliii, 214, 1862.

after the animals were killed. Hence, McDonnell deems the conclusion justifiable, that the blood of animals living on vegetable food is normally saccharine; but that the liver does not transform its amyloid substance into sugar, and pour it out into the blood of the hepatic vessels.

(60.) On the 21st of June, PAVY presented a paper supplementary to his former one, to the Royal Society. In it he shows that blood collected from the right side of the heart after death affords an abundant indication of sugar, while if removed by catheterism during life it contains but a trace. Hence all inferences as to the ante-mortem state, drawn from post-mortem observations, are erroneous. He proves, moreover, that the heart excised instantly after killing, contains blood as free from sugar as during life; and demonstrates that very slight causes produce in the living animal, a considerable amount of sugar in the circulation; simply by interfering with the breathing, a strongly marked diabetic state of the urine may be induced within an hour. To obtain, therefore, a fair specimen of blood, even by catheterism, the animal must remain perfectly tranquil during the operation. Pavy further asserts that the blood found in the right side of the heart is not more saccharine than portal blood; that the saccharine condition of the liver, which has been hitherto regarded as a normal one, is in fact the result of a post-mortem change which takes place with an astonishing rapidity; that the true function of the liver is to form the glycogenic substancewhich the author calls hepatine ;-that the real function of this substance is yet an open question; that though it may be transformed into sugar by any ferment, yet that normally, it is not so changed during life; that abnormal states of the circulation and probably of the blood, as well as certain conditions of the nervous system, cause the production of sugar; that after section of the spinal cord just below the phrenics, the temperature of the body falls, and the transformation of hepatine becomes so slow that the true physiological process is at once defined; that this fact may readily be experimentally demonstrated in the livers of animals which have naturally a low temperature, as the frog, the oyster and the mussel; that the use of starchy and saccharine food increase the amount of hepatine in the liver and hence increases the size of this organ; that his previous experiments on dogs are confirmed by new ones made on rabbits, thus proving the conversion of sugar into hepatine; that it is highly improbable that sugar is changed into hepatine merely to be changed back again by the same organ; that one and a half parts of hepa*Proc. Roy. Soc., x, 528.

tine yield in the liver after death, one part of sugar; that hepatine and sugar differ widely in osmotic power, a fact which accounts for the retention of the former in the hepatic cells; that the liver becomes strongly saccharine on ligating the portal vein; that then the blood also gives the sugar-reaction, and in one case it was found in the urine; and that the introduction into the circulation of sodic carbonate prevents the diabetic state ordinarily induced by injury of the sympathetic system.

(61.) In a paper read August 6th,* DE LUCA gives the results of his examination of the liver of a person who had died from cerebral congestion, whose pancreas was partially atrophied. He found 1st, that this liver contained saccharine matter capable of reducing copper-tests and of fermenting with yeast; 2d, that when washed free from sugar and allowed to stand, a new quantity was formed, thus proving the presence of glycogenic matter; 3d, that when thus washed, glycogenic matter not capable of reducing copper tests or of fermenting, could be prepared from it; and 4th, that this same whitish substance boiled with hydrochloric acid for a few minutes reduced the tests, fermented and yielded a crystallized compound with sodic chlorid. DeLuca concludes therefore, that the glycogenic function of the liver was not at all modified by the disease of the pancreas.

(62.) On the 5th of November, COLIN presented a memoir to the French Academy† on the relation of the production of sugar to the re-absorption of fats, and also to the animal heat during abstinence and hibernation. The following are his conclusions: 1st, The re-absorption and combustion of fats, the production of sugar, and the maintenance of the animal heat to its ordinary degree, are phenomena intimately connected and mutually dependent. 2d, Abstinence cannot long be supported in lean animals; it produces a very rapid lowering of the temperature which is coincident with the almost complete disappearance of sugar in the liver, the blood, the lymph, and other liquids normally saccharine. 3d, With fat animals or those moderately so, the duration of the abstinence-all the other conditions being the same-appears to be exactly proportional to the quantity of fatty matter held in reserve in the tissues; so long as this fat exists in the animal, its life is sustained, the sugar is renewed in the liver as well as in the other nutritive fluids, and the temperature of the body is not notably lowered. 4th, During hibernation, the activity of the sugar-production is proportional to the reabsorption of fat. 5th, Finally, in all animals deprived of + C. R., li, 684.

* C. R., li, 217.

food, the liver experiences some remarkable changes; it becomes partially atrophied, and its cellules lose their fat, which is replaced by sugar.

(63.) In May, 1861, GORUP BESANEZ published a method for the preparation of glycogen. His colleague Gerlach, in washing the liver of a child two years old by injecting water into the portal vein preparatory to a permanent injection, noticed that the escaping water which at first was bloody and dark colored, grew brighter and finally became milky, though it never became transparent and clear. On standing, this milky fluid deposited a flocculent coagulum, leaving the liquid above strongly opalescent. A similar result was obtained from the liver of an adult three to six days after death. On examination Gorup Besanez found the opalescence to be due to glycogen; and he gives the following method for preparing it pure: The opalescent liquid from the liver is freed from albuminates by acidulating with acetic acid, heating rapidly to boiling, and filtering from the coagulum; it is then mixed with twice its volume of 90° alcohol; a bulky precipitate falls which, after standing some hours is collected on a filter, washed out with alcohol, dissolved in water, heated to boiling with a few drops of acetic acid-which causes the separation of a slight granular coagulum-filtered, and mixed with twice its volume of alcohol as before. A snow-white flocculent precipitate of glycogen is thrown down, impure only from the presence of a little fat; freed from this by ether, and dried in vacuo, it forms a brilliant white powder like flour, resembling very strongly starch or inulin. Water dissolves it to a strongly opalescent liquid, not cleared by boiling. The solution is colored wine-red by iodine, but is not precipitated by glacial acetic acid, becoming rather clearer by this treatment; thus agreeing with the observations of Hensen, Scheerer, and Lochner, but in opposition to those of Bernard and Lehmann. The strong opalescence of the liquid prevented any determination of its rotatory power. On analysis, his assistant Klinksieck obtained numbers agreeing perfectly with those of Kekulé, viz: carbon 44.5, hydrogen 6'35, oxygen 49 12=100; leading to the formula H,,,. Since Pelouze deduces the formula H12, and Lochner €,H,,,+H,, Gorup Besanez sugests that either the method of preparation affects the result, or that there are several carbohydrates in the liver, and hence that different methods of preparation, give different products. At all events the differences in composition and properties are too great to be ascribed to errors of analysis or observation.

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* Ann. Chem. Pharm., cxviii, 227.

(To be concluded.)