818 General Notes. [October, 
method is apparently more expensive than the other, but the ex- 
tract is in either case more expensive than the other preparations, 
though very conveniently preserved and handled. 
The extract may be greatly diluted with water and then applied 
by means of any atomizer. Professcr E. A. Smith of Tuscaloosa, 
Ala., found that, diluted with water, at the rate of one part of the 
extract to 15 of water, and sprayed on the leaves, it kills cotton 
worms that have come in contact with the solution in a few min- 
utes. The mixture in the proportion of one part of the extract 
to 20 parts of water was equally efficacious, and even at the rate 
of 1 to 40 it killed two-thirds of the worms upon which it was 
sprayed in 15 or 20 minutes, and the remainder were subsequently 
disabled. In still weaker solution or at the rate of 1 to 50 it loses 
in efficacy, but still kills some of the worms and disables others. 
Professor Smith experimented with the extract obtained by dis- 
tillation, and another series of experiments with the same method 
was carried on last year by Professor R. W. Jones of Oxford, 
Miss. He diluted his extract with twenty times its volume of 
water and applied it by means of an atomizer on the cotton worm 
and the boll worm with perfect success. Mr. E. A. Schwarz tried, 
worms. . 
4. Pyrethrum in simple water solution—So far as our ate 
ments go, this method is by far the simplest, most economica 
and efficient. The bulk of the powder is most easily dissolved in 
water, to which it at once imparts the insecticide power. No con- 
stant stirring is necessary and the liquid is to be applied in per 
same manner as the diluted extract. The finer the spray 10 whic 
the fluid is applied the more economical is its use and the greater 
the chance of reaching every insect on the plant. Experiments 
with Pyrethrum in this form show that 200 grains of the power 
stirred up in two gallons of water is amply sufficient to kill ee 
cotton worms, except a very few full-grown ones, but that te 
same mixture is not sufficiently strong for many other insects. 
the boll worm, the larva of the Zerias nicippe and such species 
are protected by dense, long hairs. Young cotton worms can , 
killed by 25 grains of the powder stirred up in two quarts © 
water, 
The Pyrethrum water is most efficacious when firs 
loses power the longer it is kept. The powder gives the w a 
a light greenish color which, after several hours, changes % 
1Vide American ’ Ke 
* From one tok cing et Red po Fags aia was made, each drop of the 
! a ct 
extract representing one grain of the powder. The actual cost of making the extra 
was 50 cent 
t made and 
ater 
