REVIEWS. 
67 
was opened up ; and it is this field which Dr. Radcliffe has laboured at so 
energetically and well. For example, he has found that a single inch of the 
frog’s sciatic nerve exposed a current of electricity to a resistance equal to 
40,000 B.A. (British Association) units, or as much as “ eight times that of 
the whole Atlantic cable.” But it is with the new and wonderfully exact 
instrument devised by Sir W. Thomson that his most remarkable researches 
were conducted, and we may quote a few lines to show this. 
“ Seeking for tensional phenomena of animal electricity in muscle and 
nerve by means of the new quadrant electrometer, I soon found that the 
sides and ends of the fibres were charged differently — the former positively, 
the latter negatively — and that these evidences of charge disappeared in a 
great measure during action. I soon found the evidences of the charge for 
which I had searched before almost in vain ; but I found more than I 
expected. Expecting to find a single charge, I found a double charge ; and 
what to think of this state of things I could not at all see at first. The facts 
would not chime in with preconceived conceptions, and the end was, that the 
conceptions had to be modified to suit the facts.” 
The idea previously held by the writer was quite the opposite of this, for 
it conceived that the muscular fibres were charged with one kind of elec- 
tricity during rest, and that in this way the molecules were kept in a state 
of mutual repulsion. But this idea was impossible to reconcile with a 
belief that there was a double charge of electricity in each muscle, and this 
latter was unquestionably a fact. Here, then, a new series of views forced 
themselves on Dr. Radcliffe’s attention, viz. that the natural electricity 
present in the muscle produced the state of muscular relaxation and elonga- 
tion in a different way from what he formerly supposed ; that the tissues 
presented a great resistance to electricity; that the sheaths acted as di- 
electrics ; that this being the case, a charge of one kind of electricity on 
the outsides induced a charge of the opposite kind on the insides of the 
muscle, and the electric antagonism of the sides and ends was accounted for 
by the induced inside charge being conducted to the ends by the contents ; 
and, finally, that the fibres might be kept in a state of relaxation by com- 
pression of the sheaths, u arising from the mutual attraction of the two 
opposite charges, disposed, as in a charged Leyden jar, upon the two surfaces 
of the sheaths.” All these views are borne out by ample experiments, 
which are fully described by the author, but which we have not space for here. 
Dr. Radcliffe has found that all the tensional phenomena of the muscular 
fibre and all the current phenomena also, can be easily imitated upon a 
wooden model of the fibre left bare at the two ends and at the sides, 
sheathed with a coating formed of two layers of tinfoil, separated by a thin 
layer of gutta-percha, if only a charge was supplied to the outer tinfoil 
layer. He also produced experimentally the elongation of the fibre. This 
he did on a narrow band of india-rubber, covered on its two surfaces with a 
thin metallic coating, so as to allow of its being charged in the same 
manner as a Leyden jar. This appears to be a satisfactory model of a 
muscle, for it elongates under the influence of a charge of electric fluid, and, 
on the other hand, it contracts when the charge is discharged from it. This 
rude example seems abundant in favour of the view which the author works 
out so elaborately in the pages of the present work. 
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