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 
