‘270 Scientific Intelligence. 
SCIENTIFIC INTELLIGENCE. 
js CHEMISTRY AND PHYSICS. 
1. Som . Haperiinents in Electro-physiology ; by Prof. Marrevect, in 
a letter to ‘Dr Faraday, dated May 1, 1856, (Phil. Mag. [4], xi, 461.)— 
I think Ihave already told you that for some time past I have been 
making experiments in electro-physiology. Allow me now to communi- 
cate to you the results of my work. 
I have lately succeeded in demonstrating ee measuring the phenome- 
non which I have called muscular respira This respiration, whic 
consists in the absorption of oxygen and ra £ esksilation of carbonic acid 
and azote by living muscles, and of which I have determined the princi- 
pal eaten and intensity compared with that of the general i 
of an ai been studied particularly on muscles in contraction 
have pared that this respiration increases considerably in the ant “of con- 
traction, and have measured this increase. 
A muscle which contracts, absorbs, while in contraction, a much 
~~ of we and exhales a much greater quantity of carbonic “acid 
han does the same muscle in a state of repose. part of the 
Mabon: acid ochidee in the air, the muscle imbibes the other part, which 
puts a stop to successive respiration and produces asphyay of the muscle. 
Thus a muscle soon ceases to contract under the influence of an electro- 
magnetic machine when it is enclosed in a small space of air; this cessa- 
tion takes place after alonger interval of time if the muscle is in the open 
air, and much more slowly still if there be a solution of potash at the 
bottom of the recipient in which the muscle is suspended. Muse Seas hick 
have been kept long in vacuum or in hydrogen are nevertheless capable, 
though in a less degree, of exhaling carbonic = while in contraction ; 
this proves clearly that the oxygen which furnishes the carbonic acid ex- 
which gives rise to heat, is also represented by a certain quantity of vis 
viva, or by an equivalent of mechanical work. I have therefore been able 
causes of this slight difference: these two numbers are therefore suffi- 
ciently in accordance with each other 
Ihave completed these researches by: some new studies on induced contrac- 
tion, that is to say, on the phenomenon of the irritation of a nerve in con- 
tact with a muscle in contraction. A great number of experiments latel: 
b 
