[84] REPOKT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 
inflammation and inflammation of the neighboring lymphatic glands ; no case, how- 
ever, to my knowledge, has ever been known to result seriously. Third, as to animals : # 
I know nothing of any serious accident to them. 
15. The best method yet tried is the application of the Paris green suspended in 
water, 1 pound to 40 gallons. The Paris green being the arsenite of copper, it is not 
soluble in water, and when the two are mixed the Paris green is only suspended ; 
hence it is necessary to keep the mixture constantly agitated, otherwise some portions 
will be stronger than others, and will in that case be apt to injure the plant. 
The mode of applying it differs according to the means of the planter using the poi- 
son. Many persons 'make brooms of the Mayweed (Antlumis eotula), which are handy 
and very convenient ; others use the common garden watering-pot with the perforated 
nozzle, which is expeditious, efficacious, and at the same time inexpensive. The.best 
mode yet found is with the fountain-pump; with this the work can be accomplished 
with neatness and dispatch without wetting the clothes of the one applying it. The 
poison must be applied just after the worms are hatched and begin to "crawl, other- 
wise it will be too late. It requires careful looking to find the worms at this stage of 
their existence. Four or five days after the butterfly emerges from the chrysalides 
she begins to lay her eggs, on the under side of the leaf, and after about the same time 
the eggs begin to hatch ; then look carefully under the leaf in the locality where you 
expected to find them, and almost to a certainty they are there. In order to better 
find them every planter should provide himself with a small magnifying glass, which 
will cost him only about twenty-five cents. This summer I had in my office one leaf 
from the cotton plant, and on it there were ten worms and in it at least one thousand 
holes, yet on handing it to several persons they failed to see either caterpillars or holes 
until they were pointed out to them. 
By request I received the following letter from one of our largest planters : 
Natchitoches, La., September 26, 1^79. 
Dear Sir : In 18761 experimented with arsenic to destroy caterpillars, with the fol- 
lowing result : I took one pound of 16 ounces of commercial arsenic, which cost 
about 25 cents per pound, dissolved it by boiling in 8 gallons of water ; after it was 
dissolved replaced the quantity of water lost by evaporation ; with this 8 gallons I 
went to work. 1st. Put 2 gallons of the solution in a pork-barrel of water, say 33 gal- 
lons, sprinkled two rows of cotton ; result of this application was death to both cotton 
and worms. 2d. I then used 1^ gallons to the barrel of water ; same result to the 
worms, cotton badly scalded. 3d. I then took one gallon of the solution and put it in a 
barrel of water ; this time my splution seemed to be a little too strong, but (lid no per- 
ceptible injury to the plant ; the leaves retained their color except in places. A fourth 
application of three-quarters of a gallon of the solution to a barrel of water was tried 
and found of sufficient strength to kill the worms and not damage the plant. These 
experiments were made at the same time Paris green was applied to the balance of 
the cotton on the plantation, none, however, being used when the arsenic was ap- 
plied. The rows in which the last two applications were made (i. e., 1 gallon and £ 
gallon to the barrel of water) the cotton lived and bloomed about three weeks, at 
which time the worms destroyed all of the cotton on the plantation. 
Respectfully, 
H. B. WALMSLEY. 
Dr. George E. Gillespie. 
The Paris green has been sold in this market for $1 per pound, but it can now be 
bought for from 25 to 35 cents per pound. It is calculated that three-quarters of a 
pound will poison an acre; however, if the application is made just before a rain, it 
will be necessary to repeat it. Most planters think that $1 per acre will cover all the 
necessary expenses. 
Respectfully, 
GEO. E. GILLESPIE, M. D. 
C. V. Riley, Chief U. S. E. C. 
Jackson, Miss., September — , 1879. 
In answer to some of the questions of your circular No. 7: 
4. W;irni, wei, and cloudy weather favors the appearance and reproduction of the 
Cotton Caterpillar. 
5. Never have known them to appear in the spring when June and July have been 
wet : the Lsl August is about the earliest period in this locality. 
0, In cotton of the Largest growth without regard to the situation. 
7. Observation has led me to believe that the worm in none ofits forms lives through 
•HI winters in this locality, and also form an opinion in direct variance with science 
us taught in the schools. I have attempted to arrest their increase when only a few 
