( 756 ) 
[December, 
CORRESPONDENCE. 
*,* The Editor does not hold himself responsible for statements of fadts or 
opinions expressed in Correspondence, or in Articles bearing the signature 
of their respective authors. 
ELECTRICITY AND THE ANIMAL. 
I have read with great interest your remarks on Dr. Stone’s 
paper on “ EleCtricity and Health,” which was read before the 
Society of Telegraph Engineers at the Health Exhibition ; and 
also those on the experiments stated to have been made with 
artificial incubation, in the presence and absence of magnets. 
At the meeting at the Healtheries I pointed out that probably 
the discrepancy in the measurements of the eleCtrical resistance 
of Dr. Stone’s 7 feet of clinical clerk, when measured with high 
and low tension currents, and more particularly the great apparent 
fall in the resistance when measured by means of the alternating 
current, might very probably arise from an opposing electro- 
motive force being measured as resistance. 
I pointed out that in every part of the animal body we have 
an artery and a vein running side by side. When we pass an 
eleCtric current through a portion of the body — say through a 
limb — the current passes along the two blood-vessels in the same 
diredtion with reference to the limb itself ; but it must be remem- 
bered that, looking upon these vessels, in comparison with their 
surroundings, as conductors, each would create its own magnetic 
field in concentric circles round it. so long as the current was 
passing through it. 
In each, however, the fluid blood — which is here the conductor 
— is, we know, in rapid motion, so that we may expedt to have 
developed in each, seeing that it is a conductor moving in a 
magnetic field, an opposing eledtro-motive force, which I suggest 
is measured as resistance. 
This supposition is borne out by the fadt that with the alter- 
nating current, which we know creates but a comparatively feeble 
magnetic field, the measured resistance is strikingly reduced. 
I believe I am corredt in stating that we have no other case 
of a body altering its eledtrical resistance, without — either first 
or at the same time — altering some other physical condition, and 
therefore, it appears to me, we are bound to look further for a 
solution, and not to accept at once mere experimental faCts, 
which do not agree, as proof of physical conditions in the animal 
body which do not exist in other bodies. 
It may, of course, be objected that the magnetic field so ere- 
