J. Trowbridge—Electro-motive action of Liquids. 343 
the muscular currents. It will be seen that when we experi- 
ment with the muscle itself, we have a vessel containing fresh 
blood, with all its chemical properties active, separated by the 
sheath of the muscle from the clay guards placed upon the 
cushions of the galvanometer. An action must take place 
between the fluids of the muscle and the saline solutions of the 
connecting apparatus, which is extremly difficult to distinguish 
om the muscular current, when we consider that the fluids in 
their natural state in the muscle must exert a more definite 
chemical action than when they are removed and put in an 
artificial test muscle. : 
When membranes are used instead of clay partitions, endos- 
moti¢ action may arise. Graham has shown, however, that the 
membrane must be chemically affected by the separated liquids 
in order that an appreciable action may take. place. This 
source of error can be shunned by using unbaked sculptor’s clay 
kneaded in sulphate of zinc. We cannot affirm conclusively, 
however, even in this case, that the membranous sheath of the 
muscle is not acted upon by the blood and the sulphate of zinc 
in the clay partition. 
pikes (., Ramaret 
YT i eng i: 7” 
pve | \ « MO, Eg BS jp bead 
y Pe, 4 
Ne pe = id - 
er ¥ a sa D ihe 
7 a ee < 
In the following experiments I placed the terminals of the gal- 
vanometer in an oblong vessel filled with sulphate of zine ; an 
filling a Utube with the liquid to be experimented with, 
closed the ends with pieces of bladder prepared with the white 
of an gg, and dipped them in the bath of sulphate of zine. 
