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Dr. F. W. Pavy on the Physiology of [June 21, 



IV. " The Physiology of Sugar in relation to the Blood. — No. 2." 

 By F. W. Pavy, M.D., F.R.S. Received June 21, 1877. 



In my communication read at the last Meeting of the Society I 

 described a gravimetric process of analysis adapted for the quantitative 

 determination of sugar in blood and such like organic products. This 

 process, after a little practice, is easy of application, and with proper 

 care in manipulation admits of great accuracy being attained. I purpose, 

 in this communication, giving results obtained by its means, showing — 



(1) The amount of sugar existing naturally in the blood ; 



(2) The comparative states of arterial and venous blood ; 



(3) The spontaneous change ensuing after the removal of blood from 

 the system. 



From the rapid and marked manner in which the amount of sugar in 

 the blood becomes influenced by altered states of the system, it is neces- 

 sary that certain precautions should be strictly observed in order to obtain 

 a representation of the natural condition. From what I have said upon 

 former occasions it will be evident that if the blood is collected for 

 examination during life, the animal must be at the time in a perfectly 

 natural or tranquil state, and, if after death, the opportunity must not be 

 given for the post mortem change occurring in the liver to exert its influ- 

 ence upon the contents of the circulatory system. 



Subjoined are given three series of results illustrative of the amount 

 of sugar existing naturally in the blood of the dog, sheep, and bullock. 

 In two of the series six and in the other seven observations are supplied, 

 and it is hardly necessary to remark that they represent observations taken 

 just as they happened to present themselves. In every observation two 

 separate analyses of the sample of blood were made. The results obtained 

 in each are stated, and the mean taken as representing the amount of 

 sugar present. 



The blood from the dog (in Observations 1 to 6) was obtained by pithing 

 the animal and instantly inserting a scalpel into the chest and freely 

 incising the heart and large vessels. The chest was then quickly opened 

 and the blood dipped out and treated for analysis before coagulation had 

 occurred. In Observation 7 the blood was obtained by division of the 

 jugular vein instantaneously after the process of pithing. So quickly 

 does sugar in quantity find its way from the liver into the blood after 

 pithing has been performed, that it is necessary the steps of the opera- 

 tion of collection should be carried out with the utmost speed. 



The blood from the sheep was obtained from animals slaughtered for 

 consumption as food, the mode of killing being that commonly practised, 

 viz. passing a knife through the neck and dividing the vessels. % The 

 results represent the condition of the first portion of the blood that 



