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



material ; but the larger portion remains incorporated with, the solid 

 residue and is susceptible of being brought into view by boiling with 

 potash and subsequent precipitation with spirit. 



Bernardin (glycogen) added to blood behaves in a similar way. It 

 is carried down, in great part, by the precipitated matter when coagu- 

 lation is induced, and afterwards so tenaciously held that only the 

 minor portion is removed by washing with water. The proportion 

 dissolved out by water has varied considerably in different instances, 

 and I have been led to question whether, in some cases, it may not be 

 held to a more fixed extent than in others. I was at first much 

 puzzled to know what had become of the substance, and it seemed, 

 until I recognised it in the coagulated residue, that contact with blood 

 led to an immediate extensive disappearance. To recover it, the 

 coagulated matter requires to be subjected to disintegration by boiling 

 with a caustic alkali. In some experiments, a notable amount of 

 Bernardin has still remained unaccounted for, but, in some others, it 

 has been nearly all recovered. For instance, in two recent experi- 

 ments, after half an hour's exposure to a temperature of from 100° to 

 110° F., the following results were obtained : Bernardin equivalent to 

 0*112 grm. of glucose was in each case added, and Bernardin equiva- 

 lent to 0*105 grm. of glucose in each case recovered. In another 

 experiment Bernardin equivalent to 0'294 grm. of glucose was added, 

 and Bernardin equivalent to 0*269 grm. of glucose recovered. I con- 

 sider that further observations upon this subject require to be under- 

 taken. 



It is known that precipitates have a tendency to carry down other 

 substances with them, and this principle, it may be suggested, 

 accounts for what has been adverted to above. I am inclined to think, 

 however, from a review of all the evidence before me, that there is 

 something more than this at the foundation of what occurs. The 

 question may be raised whether there is not some feeble combination 

 existing, and whether this may not have a bearing of considerable 

 physiological importance. Subjoined are results touching the point 

 under consideration. 



A weighed quantity of liver from a recently killed dog was reduced 

 to a pulp and thoroughly extracted with alcohol for the removal of 

 glucose. The coagulated residue from the alcoholic washing was then 

 extracted with repeated washings of boiling water till the washings 

 came away clear instead of lactescent as at first. The washings were 

 collected and the Bernardin (glycogen) estimated by conversion into 

 glucose and calculation from the glucose found. After being thus 

 washed the liver residue was kept in a moist condition till the follow- 

 ing day, when the process of washing and estimation of the extracted 

 Bernardin was again performed. The process was subsequently re- 

 peated in a similar way ; and, finally, the liver residue which had been 



