CHAP. IV. §. V. DUEING EESPIEATION. 47 



dition, and that this state or condition is partly 

 produced and maintained by the various secretions 

 that take place in the animal body. How far the 

 fluidity of the blood, and the vitality of the blood, as 

 it is called, are dependent upon this electric state or 

 condition, are questions which must necessarily 

 arise in our minds. The particles of the blood, 

 also, must under these circumstances exist in a state 

 of self-repulsion : and may not this fact, it may be 

 asked, tend to explain some of the phenomena 

 connected with the circulation of the blood in parts 

 not dependent upon the vis a tergo action of the 

 heart, and also those connected with the coagula- 

 tion of the blood when taken from the living 

 animal ? Before concluding this Section let me 

 just observe, that a clue has now been obtained to 

 the non-appearance of any effect upon the galva- 

 nometer when the two electrodes are inserted into 

 an artery and a vein, a point previously established by 

 the experiments of Podillet and Mtjllee^. As the 

 blood in the two vessels is in the same electric state, 

 no effect could occur upon the needle ; thus proving 

 the fact, well established by Faeaday, that in order 

 to obtain cdeeent fobce, the circuit form must be 

 given to the arrangement, i. e. that the electrodes must 

 he brought into contact, or by means of some conducting 

 mass, with the anion and cation originating the power\ 

 There are one or two points which must now be 

 noticed. It may be supposed, first, that the effects 



' Loc, cit. ' Experimental Researches, vol. ii. p. 5] . 



