ANIMAL ELl'XTRICITY. — LECTURK H. 



ence between the bit of nerve and the entire organism ; 

 pure water has certainly no such toxic effect on man as 

 it has when directly applied to one of his tissues. 



Of the several materials just alluded to, by far 

 the most interesting and important is the gas, carbon 

 dioxide. It has perhaps been a little unfortunate that 

 I fell into the hands of carbon dioxide so early 

 in the investigation, for its allurements have been so 

 great, the hints it has vouchsafed have been so 

 significant yet so mysterious, that it has crushed out 

 nearly all other claimants upon my time, and pre- 

 vented me from pursuing as extensively as I could 

 wish that superficial survey of a large number of 

 chemical reagents which in the infancy period of 

 an inquiry is the necessary preliminary to further 

 and deeper analysis of the mode of action of a 

 few chosen substances. 



Nevertheless, considering that carbonic acid is 

 one of the two principal disintegration products of 

 all living matter — the vehicle of the respiratory 

 export of carbon from the organism — that it produces 

 with unmistakeable clearness effects that might have 

 been predicted a priori were we only endowed with 

 sufficient imaginative wit ; considering further, that 

 from these data we shall be able to draw inferences 

 as to the existence and nature of physical changes 

 effected within the nerve itself, and put those infer- 

 ences to the test of clear-cut experiment, I cannot 



