Bulletin gi May, 1902 



NEW HAMPSHIRE COLLEGE 



AGRICULTURAL EXPERIMENT STATION 



Killing Woodchucks with Carbon Bisulphide 



BY CLARENCE M. WEED 



Much damage is done to various crops every year bv the 

 common woodchuck or ground hog. Many ways of exter- 

 minating these animals have been devised, but on the whole 

 the simplest and most satisfactory method is that of the use of 

 bisulphide of carbon, an inflammable liquid which on expo- 

 sure to air volatizes into a vapor that is very destructive to an- 

 imal life. 



This substance has been in use for several years for destroy- 

 ing ground squirrels in the Western states, and has also been 

 largelv used for killing: insects in mills and factories. It has 

 often been recommended and utilized to destroy woodchucks, 

 but its merits for this purpose do not seem to be very gener- 

 ally appreciated. 



It is the purpose of this brief loulletin to record a series of 

 experiments, covering several seasons, in the use of carbon 

 bisulphide as a v/oodchuck exterminator. The experiments 

 have been carried on with the help of Messrs. A. F. Conradi, 

 W. F. Fiske, and R. A. Cushman, as well as of Mr. Percy 

 A. Campbell, who has reported the results of his work in an- 

 other part of the state. 



One special advantage of carbon bisulphide is that its vapor 

 is more than twice as heavv as air, so that in a woodchuck 

 burrow it will follow along the hole until it reaches the bot- 

 tom, crowding the air above it to the top. As the animal is 

 likely to be in the lower part of the burrow it is almost cer- 

 tain to inhale the poisonous vapor and be killed. 



THE SERIES OF EXPERIMENTS 



Our first experiments in the use of bisulphide of carbon for 

 killing woodchucks were made in 1897 when Mr. Fiske 



