34 INJURIOUS INSECTS OF 1904. 



Effect of the Gas on Hiunan Beings: This liquid can be safely 

 handled by workmen in the mill if they will take the precaution to 

 go at once into the open air when they feel any bad effects from 

 inhaling the gas. The mill, during this process, should be tightly 

 closed to make the work more effective, and in consequence is 

 filled with fumes. If these fumes are inhaled by the men for some 

 length of time without the precaution above mentioned of going 

 frequently to the fresh air, temporary nausea and sickness may 

 result, while prolonged exposure to dense fumes in a tight room 

 might result very seriously. Nature, however, gives one warning 

 in plenty of time to avoid danger. Then, too, in a case which came 

 under the writer's observation, men working with the stuff became 

 more or less immune, and one individual was hardly affected at all. 



As is evident, the treatment of a mill in this way should be in 

 charge of a reliable and. competent man of intelligence, one fully 

 posted as to the nature of the chemical his men are handling. 



Methods Which Have Been Tried and Found Ineffective or Less 

 Desirable than the Preceding. 



Fumigation ivith Bisulphide of Carbon: Although this has been 

 the common practice in the past, and is generally recommended in 

 cases of attack of this insect, actual experience with its use does 

 not bear out the recommendation, in that it does not appear to kill 

 the moths or worms under the conditions which prevail in almost 

 every mill. It may be effective against other insect pests with 

 which flour mills are troubled, thus giving rise, from published re- 

 port, that it is effective also against the Mediterranean Flour Moth, 

 but we know of at least three instances where it was tried in large 

 mills and proved valueless. 



The process consists in placing pans of carbon bisulphide on 

 the different floors, using a definite amount of the liquid (about 

 one part to every one thousand parts of atmosphere), first making 

 the room as tight as possible, opening up all spouts, spindles and 

 other apparatus in which the moth or its larva is found. The chief 

 obstacle here is the almost utter impossibility of making the large 

 rooms air tight. Then, too, as evidenced by the testimony of a 

 Pennsylvania miller a few years ago: "When placed in plates it 



