1875.] Dr. F. W. Pavy on the Production of Glycosuria. 57 



and found to give no reaction with the copper test, while that collected 

 at its termination was freely charged with sugar. Urine was again col- 

 lected half an hour later, and sufficient having been obtained for a 

 quantitative analysis, sugar was found to be present to the extent of 20 

 grains to the fluid ounce. 



In another experiment, conducted in a similar manner, I tied the coeliac 

 axis and obtained a similar result. The urine collected a quarter of an 

 hour after the process of inhalation was highly charged with sugar. 



In each of the above experiments the perfect deligation of the arteries 

 was verified by dissection after death ; and with the amount of blood 

 allowed to reach the portal vein so diminished, the liver must have re- 

 ceived very much less than its ordinary supply. I consider the conclusion 

 to be warranted that it is by virtue of its presence in the blood (and 

 probably through the combination which possesses the same physical 

 properties as oxy-haemoglobin) that carbonic oxide determines the escape 

 of sugar from the liver and thence the production of glycosuria. 



The fundamental point of physiological interest brought forward in 

 this communication is that the passage of oxygenated blood through the 

 liver excites the transformation of its amyloid substance into sugar. 

 Although I abstain at present from committing myself to any settled 

 conclusion regarding the precise modus operandi, yet the evidence before 

 me leads me to think that the effect is due to the action of the oxidized 

 blood as a ferment, and not to the direct influence of oxygen ; and under 

 this view the inhalation of carbonic oxide may lead to the result observed, 

 by the compound with haemoglobin, which possesses corresponding phy- 

 sical properties to oxy-haemoglobin, acting in a similar way. I am inclined 

 also to think that the production of sugar is only one part of the event 

 occurring. 



It is a noteworthy fact that in the puff-ball and carbonic oxide ex- 

 periments there was a strikingly rapid disappearance of amyloid substance 

 from the liver. Under ordinary circumstances the decoction of the liver 

 is milky, from the presence of amyloid substance, but under the conditions 

 referred to the decoction was found nearly or quite clear. Even in the 

 space of about an hour I have in some instances observed the decoction 

 yielded to possess no sign of milkiness ; and there was other evidence to 

 show that the amyloid substance had disappeared. 



On giving attention to the position where amyloid substance is dis- 

 coverable, it appears to be especially where a limited amount of oxygen 

 exists that it is present. There is no organ in the body supplied with 

 venous blood like the liver, and in correspondence there is no structure 

 which is charged to a similar extent with amyloid substance. During the 

 first portion of intra-uterine life the liver is free from amyloid substance, 

 while the liquor amnii and the fluid of the allantois contain sugar. May 

 this not arise from the oxygenated blood of the umbilical vein causing 

 the amyloid substance, which might otherwise accumulate in the liver, 



