108 
Laundry Soap. 
Experiment 16.—Three applications of strong solutions of lamn 
soap were made with a brush to infested leaves, from the 19th 
the 2*2d July, with the effect to destroy all the bark lice, oc 
sionally, however, with trifling damage to the leases. The effect 
these applications apparently differed but little from those of 
whale oil soap. 
Py rethrum. 
Experiment 17.—Although expecting nothing from the applicat 
of pyrethrum, we made a few experiments with it, commencing J 
19. As they were all entirely inefficient, the results need not 
given further than to say that the fresh pyrethrum powder suspern 
in water in quantities varying from a tablespoonful to the gallon 
to an excessive proportion was applied by brushing and dippi 
without any effect whatever. Pure pyrethrum was also dusted ui 
the leaves without result. 
Carbolic Acid. 
Experiment 18.—July 19, leaves infested with the young bark 
were thoroughly wetted with carbolized water (a teaspoonful of 
pure liquid acid to the gallon) and examined five hours later, 
bark lice were all alive. This experiment was twice repeated, b 
in the laboratory and the field, with only negative results. 
A few additional experiments were made with tobacco water (( 
half pound tobacco to a gallon of water); with hellebore (one ou 
to the gallon); and with a weak solution of caustic soda, in 
cases without any favorable result, every individual.being apparei 
alive in from one to three days after treatment. 
As a general result of the above series of experiments we i 
say that a kerosene emulsion diluted with soap suds to a strer 
of from two and a half to five per cent., was found effective du 
the month of July and did not injure the leaves. This was 
only substance experimented with which gave any promise of 
fulness, with the exception of the whale oil and soaps, which were ^ 
ject to the drawback already mentioned ; that is the liability to in 
the leaves if used in a solution strong enough to destroy the 1 
lice. Possibly if it were washed off shortly after application 
recommended by Dr. Lintner, the injurious result might be 
vented, but this would too greatly increase the trouble and expt 
of the application. 
Washing off the Females and Egg Masses ivith Water. 
From correspondents in Northern Illinois, I learned that lab 
June, the practice became somewhat general of washing off the 
masses and the outworn bodies of the females with jets of w 
from the hydrants, throwing the water into the tree by means < 
hose, but I have not yet been able to learn with what m 
This method was, apparently, usually applied under the mist; 
