158 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 4 



the heating of this mill, and in this case with a few alterations in the 

 arrangement of the steam pipes, and with some additional radiating 

 surface, this would be the most efficient, convenient, and least ex- 

 pensive method. To fumigate with hydrocyanic acid gas, requires 

 from two to three days, and this long shut-down, with the additional 

 <;ost of material, is a large item of expense besides being dangerous 

 to the life of the operator, while with the heat, since it can be applied 

 from Sunday morning until Monday morning, there is no loss of time, 

 very little expense, and no danger to the life of the operator. 



President Sanderson: Any discussion? 



Mr. Washburn: You do not mention anything about the eggs 

 of Ephestia. 



Mr. Dean: This mill was not infested with the Mediterranean 

 flour moth. 



Mr. Washburn: But you do not know whether you can free a mill 

 of eggs by this method. 



Mr. Dean: Since this mill showed no live insects three weeks later, 

 I believe all eggs were killed in the upper stories. 



Mr. Washburn: Then there are enough eggs in the lower story to 

 restock the entire mill. 



Mr. Dean: The point is this. Professor Washburn, if those pipes 

 had gone down to the lower floor we could have had as high temper- 

 atures there as on the upper floors. 



Mr. Washburn: Have you tried it in the winter time in Kansas? 



Mr. Dean: No. In the second experiment the temperature was 

 77° outside. 



Mr. Washburn: My point is this, with the method of piping in a 

 mill, that in the winter it would be hard to get the temperatures 

 required in the lower stories. 



Mr. Dean: All the mills would have to put in more radiation, but 

 that would cost less than shutting down for fumigation two or three 

 days. 



Mr. Washburn: In fumigating with hydrocyanic acid gas they 

 only shut down from Saturday night to Sunday morning. They do it 

 when they are cleaning the mill, and part of the cleaning process 

 with many millers is fumigating with hydrocyanic acid gas. 



. A Member: I find that the employees in mills undertake fumiga- 

 tion with hesitancy. 



Mr. Dean: I have heard men state that they would quit the job 

 before they would touch it. In the case of fumigation the mill has 



