PYRETHRUM AS USED AGAINST THE COTTON WORM. 173 
Krperiment 2, August 27. — The same mixture applied with the bellows while going 
slowly between the rows. A large proportion (estimated at two-thirds) of all the 
worms on the plants were affected, but most of them had recovered the next morning. 
Experiment August 27. — The same mixture applied with the hand. I had seen 
this method in use in Texas, where flour and Paris green were used, and convinced 
myself that it was an excellent and very economical method of applying dry powders 
to high plants. I found, however, to-day that it requires some practice to distribute 
the mixture evenly and economically. The result was about the same as in Experi- 
ment No. 2. The mixture is evidently too weak if applied in moderate quantity. 
I:\rjx rimmt 4, September 4. — Pyrethrum 1 part, mixed with 10 parts of flour, applied 
immediately after preparing, by means of the bellows. Comparatively few worms on 
the plants, and no very young ones. Again, about two-thirds of the worms affected', 
of which none or very few recovered. This mixture is evidently strong enough to 
kill all fhe worms with which it comes in contact, though it was distributed in small 
quantity. 
Experiment 5, Septe mb er 4.— Pyrethrum I part, mixed with 15 parts of Hour, applied 
with the bellows, in part thickly, i. c, walking very slowly and using the bellows 
freely, and in part, very slightly applied. In the former ease the mixture is as efficient 
ns that mentioned in Experiment 4, about two-thirds of the worms being killed; in 
the Latter case a great proportion of the worms recovered. 
F.rpcruncnt f>, Septembers. — Finely-sifted wood-ashes were substituted for the flonr; 
ratio, 1 part pyrethrum to 10 parts of ashes. Applied with the bellows. Eflfect the 
same as in Experiment 4. The mixture is much lighter than flour, and spreads more, 
but for this reason is not useful in windy weather; moreover, the preparation of the 
wood-ashes is somewhat troublesome, as they must be sifted through a very line sieve. 
Kxpaimtnt 7, September 21.— Finely-sifted prairie soil was substituted for the Hour ; 
1 p:irt of pyrethrum to 10 parts of soil. The mixture could not be applied by means 
of the bellows, as it is too heavy; neither can it be applied by means of the sieve, as 
the two materials separate at once, the powder coming to the surface. It was finally 
applied by throwing it with the hand, but it is evident that even then it is inferior 
to Hour and ashes, owing to its weight, which prevents its spreading and Hying about 
like the much lii.er and. Lighter flonr. Otherwise, the mixture acts as powerfully as 
that of pyrethrum and Hour mixed at the same rate. 
Experiment B, September 81. — The same mixture as in experiment No. 1 applied after 
it was left standing in a tight glass jar ever since August 27. Applied in moderate 
quantity by means of the bellows. Worms very plentiful and mostly small. Again, 
about two-thirds of the worms were affected, of which only a small proportion, if any, 
recovered. The mixture is evidently by far stronger now than when freshly prepared, 
ami would undoubtedly be strong enough for average-sized worms. 
Experim ent 9, September 96. — A small remnant of the mixture used In experiment 
No. 8, which had been diluted, September 81, with abont one-half the amonntof Hour, 
was applied by means of the bellows. Worms very plentiful, and of all sizes. When 
applied thickly the mixture still kills the small worms ; the larger ones that were 
affected had, with few exceptions, all recovered the next day. When applied slightly, 
even a portion of the smaller ones recovered; very small worms were, however, still 
destroyed. 
N. B. — Full-grown worms are not taken into consideration in these experiments, as 
they usually recover, unless they get a very large dose of the mixture. A number of 
trials in and out doors proved that for newly-hatched worms a mixture of one part of 
pyrethrum to 20 parts of flour applied slightly and immediately after preparing is 
amply sufficient. In these experiments, I used both the Califoniian buhach and im- 
ported insect powder (furnished to the Commission by Messrs. Lehn & Fink), with- 
out noticing any difference in efficacy between the two. 
Prof. E. W. Jones obtained very similar results. He writes, "One 
part of Pyrethrum to 20 parts of wheat flour, thoroughly mixed and 
