C 34 3 
lefs than I have generally feen the hearts of frogs 
<c make, in that time, when their thorax was opened 
cc without decollation.” — (See Whytt’s Exp. on 
living and dying animals. Eff. Ph. and Litt. vol. II. 
p. 282. — alto Whytt’s Phyf. Effays.) 
II. “ Some young gentlemen having hanged a 
“ cat, till flie was quite dead, opened the thorax, 
“ and obferved only a tumultuous motion in the 
“ heart j which foon ceafed, but was renewed by 
“ pricking it with a fharp inftrument } after this, 
“ by fqueezing the cardine nerves downwards, or 
“ otherwife irritating them, the heart was made to 
u perform two or three pulfations, which it con- 
“ tinued to do for a conliderable time whenever the 
cardine nerves were thus ilimulated.” (Whytt’s 
Vital Motions, p. 355.) I relate thefe experiments in 
the words of their excellent author, as they were 
made with no view to the dodfrine I fhall endeavour 
to fhew they enforce and fupport. 
III. Animals are killed fome fooner, others, efpe- 
cially of the cold kind, (as frogs and tortoifes, pro- 
bably on account of the largenefs of their fpinal 
marrow) much later, by cutting through the fpinal 
marrow near its origin, by which the chief commu- 
nication of the cardine nerves with the brain is cut 
off. 
The cutting through the intercofhl or great Sym- 
pathetic nerves, or the tying ligatures upon them, 
is alio fooner or later ever fatal to the animal the ex- 
periment has been tried upon ; by finally deflroying 
the motion of the heart, and inliantly wonderfully 
weakening and diiturbing its motions. See Vieuffens. 
‘ ' • Thefe 
