INSECTS AFFECTING HOUSEHOLD GOODS 235 



and freed of insects in preparation for the reception of more 

 grain." 



The heating of grain was one of the earliest means known 

 of combating grain insects, but has been little used in this 

 country. Recently, however, Prof. Geo. A. Dean (52), has 

 shown that by super-heating mills they may be rid of insect 

 pests much more quickly and cheaply than by fumigation, 

 and with no risk from fire or from cyanide poisoning. His 

 experiments show that if the temperature surrounding an 

 insect be maintained above 120 F., with a normal amount 

 of moisture, that in a very few minutes it will be killed. 

 This promises to become one of the most practicable methods 

 of cleaning mills and may be used for small quantities of 

 grain, where there are facilities for heating it or placing it in 

 a superheated room. 



