286 MR. H. F. BAXTER’S EXPERIMENTAL INQUIRY AS TO THE EXISTENCE 
tricles ; no effect. The electrode in contact with the right ventricle was inserted into 
the right bronchus ; effect very slight; blood positive. 
Experiment 6. — Cat. Prussic acid, swallowed. Between right bronchus and left 
ventricle ; the latter positive 5°. Between the two ventricles ; no effect. 
Experiment 7- — Cat. Prussic acid, swallowed. Between left bronchus and the 
axillary vein, which was wounded in opening the chest; no effect. Between left 
bronchus and left ventricle ; the latter positive 3° or 4°. 
There was one circumstance worthy of notice ; when the electrodes were inserted 
into the ventricles, blood did not necessarily escape from the wound upon being 
withdrawn. 
We might relate several other circuits that were formed, viz. between blood on 
each side of the chest, or between blood in the chest and blood in the abdomen; 
but as no definite conclusion could be deduced from them, we think it unnecessary. 
Other experiments might also be related all tending to the same conclusion, viz. that 
when the mucous membrane of the lungs and the blood flowing from the same part are 
formed into a circuit, the arterial blood is positive. 
When considering that the effects might be thought due to catalytic actions, we 
alluded to the changes which occur when venous blood is exposed to the atmosphere, 
to account for its being in a positive state. Flow can we apply the same reasoning 
to arterial blood ? In every case it was not exposed to the air ; but when exposed, 
should we be justified in concluding that it would again undergo the same changes 
which it had immediately undergone in the lungs? 
In concluding our remarks in reference to the electric state of arterial blood, it is 
with some degree of pleasure that we can now look back upon our former failures, 
and which at that time were a source of extreme annoyance, — we allude to our endea- 
vours to obtain evidence of current force by forming a circuit between the portal and 
hepatic veins. Pouillet and Muller had already failed to obtain any effect by in- 
serting the electrodes into corresponding arteries and veins*. Not only were we 
looking in the wrong quarter for our current, but we now find that the arterial and 
venous blood are both in the same electric state, and thus accounting for onr 
failures. 
In the following experiments a resistance was added to the circuit. A glass tube, 
* We do not deny, but think it highly probable, that with delicate g-alvanometers some effect might occur. 
Assuming that a slight effect were obtained, it would then become a question whether the effects were not due 
to the changes which occur at the electrodes, rather than at the points of nutrition or secretion. The physical 
philosopher has an undoubted right to call upon the physiologist to point out the anion and cation in hi.s cir- 
cuit, or some adequate cause for the current. The fact is, the vagueness associated with the term current has 
misled physiologists. We are firmly convinced, that, without extreme care, a delicate galvanometer would only 
lead to confusion ; there is no difficulty in obtaining an effect upon the needle ; if anything, we obtain more 
than we want : the great point is to account for it when obtained, i. e, to show with what class of phenomeua 
the effects may be referred. 
