[34] REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 
No. I, thrown against the under sides of the leaves at the rate of 2 pounds of dry 
arsenic to the acre ; No. 2, same quantity thrown promiscuously over the plants, the 
upper sides of the leaves getting the larger share, of course, and No. 3, applied in the 
same manner as No. 2, at the rate of 1 pound to the acre. Nos. 1 and 2 destroyed all 
the worms, hut burned the leaves of the plants badly. No. 3 showed only a partial 
clearing out of the worms, while the leaves of the plants were more or less scorched. 
A permanent solution was made by adding to 5 gallons of water 5 pounds of arsenic 
and 1 pound of sal soda, and boiling over a fire in a common iron pot until all the ar- 
senic was dissolved. This makes a solution of arsenic that will keep for any length 
of time without the slightest precipitation. 
Of this solution 1 quart was put into 40 gallons of water, which was then sprinkled 
over the cotton-plants in the usual way. It destroyed the worms, which were in 
strong force when the application was made, leaving the plants uninjured to any ex- 
tent worth naming. Several similar tests were made, all with uniform success. 
Forty gallons were found amply sufficient to go over an acre of cotton of ordinary 
growth. 
Here we have a remedy with which we can save our crop from the Cotton Worm 
at a cost of 1£ cent per acre, rating the price of arsenic at 4 cents per pound and that 
of sal soda at 5 cents, which would be very high for the latter. This, it seems to me, 
is whittling the matter of cost down to a point decidedly fine. Of course, there must 
be added to the cost of the drugs the further cost of preparation and application. 
The cost of application can be no greater than that of applying any other liquid rem- 
edy ; indeed, it should not be so great as in the case of some of them, owing to the 
fact that the liquid is a perfect solution, and, therefore, will not require the agitation 
necessary to keep insoluble poisons in suspension. The cost of preparing the satu- 
rated solution might be put down as a very small item against arsenic, but I think 
this is more than offset by the advantages of having a perfect solution at the applica- 
tion ; then, since the saturated solution will keep an indefinite length of time, it may 
be prepared at odd spells, when there is nothing else in particular to do. 
I am aware that a strong prejudice exists against the use of arsenic as an insecti- 
cide, the prejudice growing out of the mere fact, doubtless, that arsenic is well known 
by name as a deadly poison. Many persons who use London purple or Paris green 
upon their cotton without hesitation could not be induced to use " arsenic" under any 
consideration. They would tell us that to tamper with so virulent a poison as arseuic 
is extremely dangerous, while there is no particular danger attending the use of 
either of the other two articles named. Nothing could be more foolish ! I grant that 
it would not do to use a solution of arsenic for drinking purposes, nor for shortening 
one's biscuit, neither would it do any better to so use the water holding in suspension 
an insect-destroying quantity of either London purple or Paris green. The three 
poisons are really one and the same thing after all, the agent in both London purple 
and Paris green, qualifying them to destroy Cotton Worms, being arsenic and nothing 
else. Remove the arsenic from them and they would be no more effectual as insecti- 
cides than powdered chalk or common road dust. They are all deadly poisons alike, 
taken into the stomach — keep them out of that organ, and there is no danger in any 
of them. 
The planter who uses arsenic as an insecticide, preparing it in advance as suggested, 
should have a good whisky or oil barrel for containing his solution until wanted. 
This might be painted some bright color to strongly distinguish it from all other 
barrels on the place, and it would be well to have the word " arsenic " or "poison" 
painted (not daubed) in large plain letters upon its side. With such precaution as 
this, and keeping the barrel well bunged and out of the way of small children and 
live stock, there could certainly be no attendant danger. 
The rule which I have given for preparing the second solution might not hold good 
in every instance on account of variation in the quality of arsenic, due, possibly, to 
adulteration. A good and safe way to set this thing right — one that every planter 
will understand — is to make small tests in advance of the general application as fol- 
lows: 
With some small vessel, as a tablespoon, put together IliO measures of water aud 
one measure of the saturated solution. This gives you the proportion of one quart 
of saturated solution to forty gallons of water. Sprinkle this thoroughly over an 
average hill of cotton, and wait a day or so for results. If no sign is left upon the 
plants the solution is not strong enough, aud you must repeat the experiment with a 
little larger proportion of the saturated solution. If, on the other hand, the plants 
show the leaves considerably scorched and damaged, the solution is too strong, and 
you must repeat with a reduced proportion of the saturated solution, measuring with 
great care, however, so that you will be able to come exactly at the extent or addi- 
tion or reduction when you make your diluted solution on a larger scale. If, afte r 
your application, you find the leaves showing only an extremely slight, mark of 
scorch — an occasional leaf curled a little at the edge, perhaps, and a small browniwh 
