MUSCULAR ELECTRIC CURRENT. 
167 
ratio. He has further studied the influence of different 
gases, and has ascertained that the muscular pile acts 
equally in atmospheric air, in oxygen, in very rarified air, 
in carbonic acid, and in hydrogen.” 
Extensive experiments have been made as to the action 
of an electric current from a battery, when made to traverse 
muscles and nerves. One set of results is stated thus : 
“ The current w hich traverses a motor nerve in a living or 
recently killed animal, and which continues to pass along 
this nerve for a certain time, so modifies its excitability as 
to render it insensible to its passage as long as it traverses 
in the same direction ; but the excitability of the nerve 
recovers under the influence of the same current directed in 
a contrary way : when, then, a nerve has been thus modified 
by the passage of a current, we may restore to it the excita- 
bility it has lost by sending through it for a certain time a 
current, directed in a contrary w 7 ay from that which destroyed 
its excitability It is an ascertained fact, that reyjose 
produces in a living animal, the nerves of wffiich have lost 
their excitability by the action of an electrical current, the 
same effect as the passage of a current through the nerves in 
a contrary direction.” 
“ The relation between the electric current and the unknown 
force of the nervous system. — Is there an electrical current 
in the nerves of a living animal? and can it be applied 
to the explanation of the functions of the nervous system ? 
.... Matteucci has sought unsuccessfully for an electrical 
current in the nerves of a living animal Indeed, 
from what is know n of the properties and law r s of propaga- 
tion of electricity, it seems impossible to conceive the exist- 
ence of an electrical current included in the nerves ; in order 
to admit it, such a disposition in the structure of the nervous 
system as w r ould suffice to form a closed circuit must be 
proved, but this anatomists have not yet done It is 
certain that the nervous force, whatever it may be, is not 
electricity . What relation, then, is there between these two 
forces ? Matteucci’s laborious electro-physiological inquiries 
lead him to the following conclusions : there exists between 
the electrical current and the unknown force of the nervous 
system an analogy, which, if it be not susceptible of the 
same degree of evidence, is, however, of the same kind as that 
existing between heat, light, and electricity The deve- 
lopment of electricity by a crystal of tourmaline w hen heated, 
clearly proves the relation between heat and electricity : a 
similar relation between the nervous force and electricity is 
demonstrated by electric fishes. Electricity is not, however, 
