EFFECT OF ETHER AND CHLOROFORM ON FISHES. 247 



VI. SUMMARY AND CONCLUSIONS. 



1. The behavior of bullhead and sucker in gradient tank to 

 chloroform was usually indefinite and followed no rule. 



2. Bullheads exhibit a peculiar nosing reaction in ether con- 

 centration (in gradient tank) between .3 and .4 c.c. per liter 

 but not above or below these limits (except as noted). Such 

 definite and remarkable changes in behavior may be determining 

 factors in use of fish for standardization of poisons. 



3. Concentrations of about .07 c.c. (106.89 mg.) per liter 

 chloroform or of 3.69 c.c. (2,656.8 mg.) ether can kill standard 

 sunfish in an hour. 



4. In ether during third stage of anaesthesia the fish usually 

 lies belly up at the surface while in chloroform it tends to lie on 

 its side at the bottom of the bottle. 



5. Toxicity ratio between chloroform and ether {53:1 (by 

 wt.) for man and 20 : I (by wt.) for the sunfish. Such con- 

 stants may be of critical value in comparing the relative usefulness 

 of different animals for standardization uses. It may not be the 

 animal nearest man as regards toxicity ratio which is most valu- 

 able for standardization. For one where the toxicity ratio is far 

 greater, and hence an animal far more susceptible, may be most 

 accurate in perceiving and reacting to, or in dying from, the poison 

 demanding measurement. Nearness or likeness to man is of little 

 account and precision of reaction or death the paramount issue. 



6. Ether anaesthetizes the sunfish while chloroform acts more 

 as a poison, being, in a certain way, intermediate between ether 

 and the violently irritating coal-tar derivatives studied above and 

 in Shelford's work. 



I take this opportunity to express my thanks to Professor Vic- 

 tor Shelford, of the University of Illinois, for the courteous help 

 and kindly encouragement which made this paper possible. 



VII. BIBLIOGRAPHY. 

 Chase, C. S. 



'16 Physiological methods of drug standardization. J. Amer. Pharm. Assn. 



v. 4, p. 1289. 

 Eckler, C. R. 



'12 Experiments with the cat method for testing digitalis and its allies. J. 



Amer. Pharm. Assn., v. I, p. 715. 



Eggleston, Chas. 



'13 Biological standardization of the digitalis bodies by cat method of Hatcher. 

 Am. J. Pharm., v. 85, p. 99. 



