New York Agricultural Experiment Station. 207 



out of doors in the sun on a hot day. In practice, temperatures 

 above 70 degrees Fahr. will be encountered but rarely in New York. 

 The heat generated by the chemical reaction commonly raised the 

 temperature of the disinfection chamber only one or two degrees. 



As regards the influence of temperature, the most instructive 

 experiments are those in which the quantity of potatoes treated 

 equalled 8 lbs. per cubic foot. With this quantity the injury is slight 

 and if temperature is a factor of much importance it should be shown 

 here; but we see no evidence of it. Comparing Experiment No. 53 

 in which the maximum temperature was 42 degrees Fahr. with 

 Experiment No. 74 in which the maximum temperature was 87 

 degrees Fahr. we find that the injury was practically the same in 

 the two experiments notwithstanding the relative humidity was 

 somewhat higher in the latter than in the former. It should be 

 borne in mind, also, that the temperature of the cellar in which 

 the original case of injury occurred was only 45 degrees Fahr. 



In several of the experiments in which the temperature ranged 

 between 40 and 50 degrees pieces of smooth black paper were exposed 

 inside the disinfection chamber. The amount of paraformaldehyde 

 precipitated was sufficient merely to give a faint white-dusty ap- 

 pearance to the paper. In most cases it could be detected only 

 by holding the paper so that the line of vision was nearly parallel 

 with its surface. As no quantitative determinations were made it 

 cannot be stated accurately to what extent such precipitation reduced 

 the quantity of available gas, but some reduction certainly occurred. 

 However, it may be that the loss in gas was offset by the increased 

 adsorption at the lower temperature. It is known that adsorption 

 varies considerably with the temperature. Whatever the explana- 

 tion, the fact remains that severe injury occurred at temperatures 

 between 40 and 50 degrees Fahr. So far as can be determined 

 from our experiments there is no definite relation, within the limits 

 of temperature likely to be used, between the temperature of the 

 disinfection chamber and tuber injury. 



What has been said above on the subject of temperature relates 

 entirely to the temperature of the air in the disinfection chamber. 

 There remains yet to be considered the temperature of the chemicals. 

 In most of our experiments the temperature of the formaldehyde 

 solution at the time of pouring it upon the potassium permanganate 

 crystals was between 60 and 70 degrees Fahr, Probably, the tern- 



