144 Royal Society : — 



and iron, but with lead, on which sulphuric acid has no action, the 

 current is insensible. In both these liquids copper and platina are 

 negative to aluminum, and notwithstanding the apparent absence 

 of chemical action on the latter metal, weak currents are pro- 

 duced. 



• It is rather remarkable, that a metal, the atomic number of which 

 is so small, and the specific gravity of which is so low, should occupy 

 such a position in the electromotive scale as to be more negative 

 than zinc in the series. 



May 3. — Charles Wheatstone, Esq., V.P., in the Chair. 



" An Experimental Inquiry into the nature of the metamorphosis 

 of Saccharine Matter, as a normal process of the animal ceconomy." 

 By Dr. Pavy. 



The author begins by observing, that the saccharine matter met 

 with in the animal ceconomy is derived from two sources — from the 

 vegetable kingdom, and from the liver of the animal itself; in each 

 case being poured into the general circulation through the hepatic 

 veins. The liver not only enjoys the power of forming sugar, but 

 it likewise exerts (as shown by the experiments of Bernard) some 

 modifying influence over that which is traversing its capillaries and 

 which has been absorbed from the food, by which it is transformed 

 from vegetable into animal sugar, and thus rendered more apt for 

 serving in the processes of animal life. 



The sugar poured into the general circulation through the hepatic 

 veins is conveyed to the cai)illaries of the lungs, where it in great part 

 disappears, but never entirely so, according to very numerous analyses 

 which the author has made on this subject. If the blood be traced 

 onwards from the arteries through the systemic capillaries into the 

 veins, the small amount of sugar which impregnates arterial blood 

 will be found to be still undergoing a process of destruction ; and 

 what appears exceedingly interesting, this process of destruction is 

 not carried on with equal activity in the different parts of the 

 system at large. In tlie capillaries of the chylo-poietic viscera, the 

 destruction is so complete, that the blood in the portal vein may be 

 entirely free from saccharine principle, when the blood returning 

 from other parts, as that contained in the femoral or jugular veins, 

 remains slightly impregnated. This curious fact has a bearing that 

 will be presently adverted to, with reference to the views to be 

 advanced concerning the nature of the metamorphosis of sugar in 

 the animal ceconomy. 



The principal seat of destruction of saccharine matter in the 

 animal system being located in the respiratory organs, seems at first 

 sight to support the theory of Liebig — that sugar is one of those sub- 

 stances which undergoes a process of combustion, l)y its direct com- 

 bination with oxj'gen and its resolution into water and carbonic acid. 

 Some experiments on tlie temporary obstruction of the respiration 

 and the examination of arterial blood before and after the operation, 

 led the author to call in question this view, as he observed that 

 notwithstanding the supply of oxygen was cut off to such an extent 



