February, '17] 



HEADLEE: HUMIDITY AND METABOLISM 



37 



ounce bottle furnished with beans and weevils as described in the 

 first experiment suspended from the inside of each lid. In jar No. 1 

 .01 cc. of concentrated sulphuric acid (sp. gr. 1.83) was placed, in jar 

 No. 2, .03 cc, in jar No. 3 .05 cc, in jar No. 4 .1 cc, in jar No. 5 .25 

 cc, in jar No. 6 .5 cc, in jar No. 7 1 cc, in jar No. 8 5 cc, in jar No. 9 

 10 cc, and in jar No. 10 nothing whatever. The lids were set in place 

 and clamped down on rubber gaskets. 



The experiment was started August 30, 1916, and discontinued 

 December 12, 1916. 



Table Showing the Effect of a Dry Atmosphere on the Bean Weevil 



Thus we see that in a sealed chamber about 5 cc. of concentrated 

 sulphuric acid per 1,000 cc of air prevents reproduction when a limited 

 number of beans is used. The amount will have to be increased in 

 proportion to the moisture which the bean can give off. 



The next step was to determine whether the viability of the beans 

 had been injured by the exposure to dry air, and a germination test 

 was undertaken with the following results. The period of exposure 

 was 92 days. 



Table Showing the Effect of Dry Air on Vlabilitt of Bean Seed 



It thus appears that prolonged exposure of 92 days results in injury. 

 It should be remembered that the period required for sterilization 

 does not exceed 30 days, and that in view of the small amount of harm 

 of even the prolonged exposure, a period of the necessary length would 

 not injure the viability in the least. 



