1875.] Dr. F. W. Pavy on the Production of Glycosuria. 51 



it maybe expected, a fortiori, that it can decompose one of its own salts. 

 Instances of this are not wanting. 



Magnesium connected with platinum will decompose a magnesium salt, 

 the almost insoluble hydrate of magnesium being found adhering to the 

 negative metal. The deposition of zinc on the plates of an old-fashioned 

 battery, when the battery is pretty well exhausted, is a well-known phe- 

 nomenon. In our experiments with copper and silver in conjunction in 

 a solution of nitrate of copper, we never succeeded in reducing the gal- 

 vanic action to nil by our utmost efforts to exclude all oxygen : and the 

 whole of the present inquiry originated in an experiment described by us 

 before the Physical Society, that mercury and gold in conjunction would 

 decompose mercuric chloride with the deposition not only of the lower 

 chloride, but also of metallic mercury upon the gold. 



[We reserve for further consideration the part played by the water 

 in these decompositions, and the bearing of the experiments on the rival 

 theories of voltaic action. — Nov. 26.] 



II. <c On the Production of Glycosuria by the Effect of Oxygenated 

 Blood on the Liver. " (Supplement to Communication pre- 

 sented June 17th, 1875.) By F. W. Pavy, M.D., F.R.S. 

 Received August 12th, 1875. 



In my former communication I showed that the injection of defibri- 

 nated arterial blood into the portal system occasioned the immediate 

 production of marked glycosuria. In the present supplement to it I 

 purpose treating of the production of glycosuria by other conditions, lead- 

 ing to the portal blood being surcharged with oxygen. There are also cer- 

 tain collateral considerations which I shall afterwards proceed to refer to. 



After noticing the fact which has been mentioned, it occurred to me 

 to try the effect of endeavouring to saturate the blood with oxygen, 

 through the medium of respiration, to an extent beyond the capacity ex- 

 isting in the systemic capillaries for reducing it to its ordinary venous 

 condition. • 



I first directed my efforts to attain the object desired by causing an 

 animal to breathe oxygen instead of air. 



The oxygen employed was obtained from a mixture of chlorate of 

 potash and peroxide of manganese. I constructed a vulcanized india- 

 rubber mouthpiece, to fit tightly over the muzzle of the dog and exclude 

 the entrance of air. This tapered off and was connected with a piece of 

 vulcanized tubing, which passed to a balloon containing the oxygen for 

 use. A valvular arrangement was provided to allow only the oxygen 

 from the balloon to enter the chest during inspiration, and to cause the 



e 2 



