iso Royal Society of London. 
On the 13th the right honourable Sir Joseph Banks, Bart. 
president, in the chair, the reading of the Jecture on mns- 
cular motion was resumed. Mr. Peirson entered into along 
and rather amusing detail of the relative beat and pulsations 
of animals in different latitudes, with a view tu ascertain 
their effects on the muscles. In this country, he observed, 
horses pulsate 36 times in a minute, cows 48, and men 72; 
in Lapland and the northern provinces of Russia, men pul- 
sate only from 45 to 50 times in a minute.’ From these ob- 
servations on pulsation, however, no positive conclusion 
relative to its effects on muscular power could be drawn. It 
appeared, indeed, that all excess either of heat or cold is 
nimediately followed by a sensible diminution of this pow- 
er; and a fellow of this society is so affected by swimming 
in water only 10 minutes, that it occasions such a prostration 
of muscular power, as cannot be completely re-established 
in 24 hours after. Mr. P. made numerous experiments on 
the muscles of frogs, in all of which he found the muscular 
irritability completely destroyed by plunging them in water 
at the temperature of 96°: electricity, after such immersions, 
sometimes gave slight symptoms of excitability, but no hu- 
man effort could ever again restore the muscular fibre to 
ite proper tone and vigour. Cold produced precisely similar 
effects on the muscular fibre, by instantly destroying its ir- 
ritability. Here Mr. P. observed that great care was necessary 
in applying warm water to the surtace of bodies recently 
immersed i water in cases of suspended respiration, as the 
heat might be equally as bad as the cold, with regard to its 
effects on the muscular fibre, which he considered in some 
degree the organ of life. Blood, he alleged, was essential 
to life only as a necessary stimulus to muscular irritability ; 
and the abstraction of blood occasioned death, not from. de- 
stroying the continuity of that fluid, but from the want of 
its great stimulating powers to the muscles. The effects of 
Jaurel water and the vegetable poisons were next examined. 
A small quantity of laurel water was thrown into the sto- 
mach of a frog: it occasioned instant death, and on exa- 
mining the stomach, it was found that the muscular mo- 
tion of this most important organ was totally destroyed. 
a The 
