V. The physiology of sugar in relation to the blood

Abstract

In a communication published in the ‘Transactions of the Royal Society ’(1860, p. 579) I gave the results of analyses showing that what had previously been looked upon, under Bernard’s glycogenic theory, as the natural condition of the blood in relation to sugar was a fallacious representation due to a post mortem change being allowed to exert its influence. It had hitherto been asserted that the blood of the right side the heart was in a notably different condition as regards the amount of sugar it contained from that of the arterial system, an error which I discovered arose from the non-observance of certain precautions in the mode of obtaining the blood for examination from the respective parts of the vascular system. Whilst the arterial blood had been collected during life, it was customary to collect that from the right side of the heart, without any special haste, after the destruction of the life of the animal. During the period thus allowed to elapse between the moment of death and the collection of the blood, an alteration occurs from the post mortem production of sugar in the liver, which causes the blood to assume an extent of saccharine impregnation which does not naturally belong to it during life, and which had faded to be recognized in its true light. I gave analyses which show that what was formerly taken as representing he natural condition of the blood of the right side of the heart furnished from .50 to .94 per cent., or, as it is more convenient to state it, 5.0 to 9.4 per 1000 of sugar, the blood from the carotid artery of the same animals, collected during life, having contained what I described as a trace of sugar. Other analyses, three in number, were given, representing the true condition of the blood belonging to the right side of the heart during life, and the results indicated from .47 to .73 per 1000 as the amount of sugar. Bernard has recently published some communications entitled “Critiques expérimentales sur la glycémaie,” in the Comptes Rendus de I’Académie des Sciences de Paris. His statements are founded upon a method of analysis which is not only strikingly devoid of precision as a quantitative analytical process, but in itself of a nature calculated to give rise to a fallacious result.