188 THE HOUSE FLY— DISEASE CARRIER 



saucers with a piece of bread in each. The bread 

 soaked up the solution until it was saturated, and was 

 left over night. The next morning a large number of 

 dead flies were found in the neighborhood of the sau- 

 cers, and were removed. The next day many more 

 dead flies were found, and very few could be found in 

 the shop. 



On February 15th, he placed some formalin mixture 

 in a petri dish on one of the meat shelves of a private 

 meat market. Flies were very abundant. He had no 

 bread to put in, and so went down to a corner grocery 

 about one square away to get some. He was absent 

 ten minutes, and on returning found about one hundred 

 dead flies on the table where the solution had been 

 placed. The next day he examined the place in the 

 morning, and found hundreds of dead flies lying 

 around, and the numbers in the room were reduced 

 very materially. The test was conducted under fa- 

 vorable conditions, and gave excellent results. Other 

 experiments by Mr. Barber produced similar results. 



Pyrethrum and Carbolic Acid 



The fly-fighting committee of the American Civic 

 Association recommend the burning of pyrethrum 

 powder and also the dropping of twenty drops of car- 

 bolic acid upon a hot shovel, stating that the vapor kills 

 the flies. The Secretary of the Association, Mr. Wat- 

 rous, informs the writer that correspondents have com- 

 plained that neither the pyrethrum nor the carbolic 

 acid was in the least effective. I have never tried the 



