422 Dr. F. W. Pavy. Research bearing on the [June 16, 



investigation, which is calculated to lead to an extension of knowledge, 

 appears in view. Until a definite purpose to work up to, suggested by 

 something or other which has been extricated from the realm of dark- 

 ness is attained, engagement in the laboratory operations of research 

 is unsatisfactory employment. For some time, I persevered in con- 

 ducting general analytical examinations of the blood and liver, hoping 

 that, through the results obtained, light might appear in some direction 

 or other, but they failed to lead to any useful acquirement of know- 

 ledge. Later on, from information supplied by a collateral course of 

 inquiry, I was induced to conduct examinations by another method of 

 procedure, which was not likely to have been hit upon accidentally ; 

 and through these a new field has been opened out, which, if I judge 

 rightly, has given signs of proving productive of an important addi- 

 tion to our knowledge. 



It would scarcely occur to a person, unless forced upon him by what 

 he had otherwise observed, to think it necessary in relation to the 

 matter under consideration, to preserve the coagulated residue of 

 blood and submit it to examination. It will be seen, however, from 

 what has to be stated, that besides a certain amount of glucose, which 

 may be removed by alcohol, blood contains a principle which agrees 

 with Bernardin (glycogen) in being insoluble in alcohol, and converti- 

 ble into glucose by exposure to the influence of sulphuric acid and 

 heat. Some of this principle is dissolved out by water under aqueous 

 extraction, but the remainder clings to the coagulated residue, which 

 has to be subjected to special treatment in order that it may be brought 

 into view. Thus, unless a special mode of examination is adopted 

 which is not likely to suggest itself accidentally to the mind, the 

 principle in question incorporated with the coagulated residue will 

 remain concealed from observation. 



In conducting a full or detailed examination of blood, the first step 

 to be undertaken is the separation of the glucose which it contains 

 for quantitative examination. Let 25 to 50 cub. centims. of defibri- 

 nated blood be poured into five or six times their volume of spirit. 

 The glucose being soluble in alcohol is susceptible of extraction by 

 this liquid. It is held, however, more tenaciously by the coagulated 

 matter than might be expected, and hence to effect a complete re- 

 moval several washings and pressings are required. At first I was 

 deceived through not fully realising this fact, and thought I had 

 obtained evidence of the presence of glucose, of a maltose-like body 

 giving a greater cupric oxide reducing action after being subjected to 

 the converting influence of sulphuric acid and heat than before, and 

 of a substance agreeing with Bernardin (glycogen) in blood. The 

 first I found in the alcoholic extract, the second in the aqueous extract, 

 and the third in the solid residue. The maltose-like body, I have 

 since ascertained, has no real existence. The cupric oxide reducing 



