246 



HAROLD D. CLAYBERG. 



obvious and protracted, (b) In the sunfish ether produces good 

 anaesthesia allowing easy recovery, while chloroform poisons 

 rather than anaesthetizes, (c) Honigman 1 states that with man 

 chloroform is approximately three times as strong as ether (by 

 weight). With the sunfish it is about 44 by volume or 20.4 by 

 weight, (d) From previous statements it might be well to add 

 that, if death remain the biologic change used for standard- 

 ization, in certain cases it may be that other killing times may 

 prove more accurate than the 6o-minute standard. 



4. Comparison of Ether and Chloroform with Coal Tar Deriva- 

 tives.- Shelford ('17) has investigated the effect of various coal 

 tar derivatives on standard fish. In comparing these poisons 

 with the drugs previously discussed in this paper the following 

 method was used. The poisons were put up in concentrations 

 twice as strong as would be necessary to kill in an hour with the 

 object of killing the fish in approximately 15 minutes. A 

 specimen of golden shiner (Abramis chrysoleuca] was put into a 

 2-liter bottle of each poison solution and when it was dead a 

 second was inserted. The actions of the fish were noted care- 

 fully. In all cases the opercular movement was greatly increased 

 in amount and rate at the beginning of stage 2 (excitement) and 

 later weakened and decreased. The action of these coal-tar deriv- 

 atives as irritants and poisons was like that of chloroform but dis- 

 tinctly different from that of ether. A large amount of blood 

 appeared to collect at the ventral side of the body toward the end of 

 stage 2. This was notably so in quinoline, less so for aniline and 

 toluene, and observable in the others. No such phenomenon was 

 observed in the parallel chloroform and ether bottles. 



TABLE II. 



1 Cushny, op. cit., p. 163. 



