INTRODUCTORY OBSERVATIONS, XXXV 



irritability of the heart is much longer preferved 

 in drowned and ftrangled animals than in thofe 

 that have periihed in gafes. Much light has been 

 thrown on mufcular irritabihty fmce the difcovery 

 of Galvanifm ; for by that means a fpark of life 

 has often been found when it was thought totally 

 extin6l. The lols of irritability depends in a 

 great meafure on the nature of the fluid in which 

 the animal has died. By fome, it will be altoge- 

 ther deftroyed, and others will only weaken its 

 power. Drowning an animal fufpended by the 

 feet, is entirely defi:ru6tive of irritability, alfo the 

 vapour of charcoal and other gafes j but azotic 

 gas and atrtiofpherical air only diminifh, they do 

 not exlinguifii it ; and the heart of an animal^ 

 killed by its own refpiration, beats long after- 

 wards. Thus the difference is very great both 

 in the fuddennefs of death and the effeft upon 

 its body, according to the medium where an ani- 

 mal has perifiied. But it fliould be confideredj 

 with the utmofl attention, whether any of the- 

 charaihleriP.ic lymptoms precede, accompany, or 

 follow death. 



From numerous experiments, it appears that 

 death, in ftagnant rdr or in mephitic gafes, may 

 proceed from uiffocation, from injury of the muf- 

 cular fibre, from affedtions of the nerves, cr all 

 three combined, or perhaps from the cheiaicai 

 d 2 chang-.^ 



