Thomas. — Effects of Certain Oils Upon Brook Trout 129 



creosotes, dark spots covering half of the body were observed. 

 In one or two cases the action of one or more fins was inhibited, 

 and in general the nervous system appeared to be greatly affected. 

 Fish in solutions of creosote would at times live for days with 

 apparent loss of motor control. They would remain on their 

 sides or backs practically motionless except for gill movements. 

 At times the fish would quiver over the whole body, but were 

 unable to swim or control their movements. When taken from 

 solutions of the creosotes and put into pure water the fish would 

 in many instances regain normal movements and to all appearances 

 recover. The effect of the creosotes and like materials is so 

 marked that behavior due to their presence cannot easily be 

 mistaken. 



The toxicity of creosote solutions may be seen from the fol- 

 lowing experiments in which fractional distillates of commercial 

 creosote were used. One fish was used in each experiment. 



FRACTION DISTILLING UP TO 205° C. 



* A 1% solution was obtained by shaking 1 cc of the creosote with 99 cc 

 of water. 



