on muscular Motion , 
25 
treatment. The same experiment was made on the muscular 
fibres of lamb and beef, twelve hours after the animals had 
been killed, with the like results. Neither vinegar, nor water 
saturated with muriate of soda, nor strong ardent spirit, nor 
olive oil, had any such effect upon the muscular fibres. 
The amphibia, and coleopterous insects, become torpid at 
34,°. At 3 6° they move slowly, and with difficulty ; and, at a 
lower temperature their muscles cease to be irritable. The 
muscles of warm-blooded animals are similarly affected by cold. 
The hinder limbs of a frog were skinned and exposed to 
cold at 30°, and the muscles were kept frozen for eight hours, 
but on thawing them, they were perfectly irritable. 
The same process was employed in the temperature of 20°, 
and the muscles kept frozen for twelve hours, but that did not 
destroy the irritability. 
In the heat of too 0 , the muscles of cold-blooded animals fall 
into the contractions of death ; and at 110°, all those of warm 
blood, as far as these experiments have been extended. The 
muscles of warm-blooded animals, which always contain more 
red particles in their substance than those of cold blood, are 
sooner deprived of their irritability, even although their relative 
temperatures are preserved ; and respiration in the former 
tribe is more essential to life than in the latter. 
Many substances accelerate the cessation of irritability in 
muscles when applied to their naked fibrils, such as all the 
narcotic vegetable poisons, muriate of soda, and the bile of 
animals ; but they do not produce any other apparent change 
in muscles, than that of the last contraction. Discharges of 
electricity passed through muscles, destroy their irritability, 
but leave them apparently inflated with small bubbles of gas ; 
MDCCCV. E 
