48 CUERENT FOECE CHAP. IV. §. V. 



that have been obtained may arise from thermo- 

 electric actions, since Bboquerel" and Beesohet 

 have ascertained the existence of a difference in 

 temperature between the arterial and venous blood 

 by means of a galvanometer ; secondly, that they 

 may also arise from the actions that take place upon 

 the surface of the platinum electrodes. We will 

 now notice these objections. 



First, as to catalytic actions, or the combining power 

 of platinum. There are strong experimental reasons 

 for believing, that when blood escapes from a woimd, 

 it enters into combination with the oxygen of the 

 atmosphere ; when a plate of platinum therefore is 

 in contact with the blood, actions similar to those 

 which occur in the gas-battery take place. We have 

 a right to suppose that similar actions would occiur 

 at the other electrode, namely, that in contact with 

 the bile; still, it might not necessarily follow that 

 the latter would counteract the effects of the former. 

 Judging then from the direction of the current, the 

 effects may be fairly supposed to be due to the 

 actions which occur between the atmosphere and 

 the blood, or, in other words, to catalytic actions. 



There can be no doubt that the effects observed^ 

 are partly due to catalytic actions ; and we may even 

 go further and say, that they must be so as a necessary 

 consequence. Just now it was necessary to suppose 

 the, blood to be acid — ^to contain an anion — to account 

 for the effect ; now we are obliged to suppose it to 

 " Loc. cit. torn. vii. p. 30. 



