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No. 33.] 315 
depth. The fact that the fibrous roots are almost always most 
numerous in the upper layers of the soil would seem to indicate that 
a dearth of moisture had not existed here. 
Insecticides. 
We made many experiments upon the injurious insects that 
attacked our garden crops the past season, but the results of our work 
may be briefly told. We regard it as unnecessary to detail experi- 
ments that yielded negative results, however much care was used in 
carrying them out.- Our experience leads us to the opinion that a 
special mode of treatment must be adopted for almost every destruct- 
ive insect. 
The Turnip Flea Beetle. 
We made many applications with the view of discovering the most 
efficient preventive for the injury wrought by the turnip fe beetle, 
*Haltica striolata (Ill.). Among those we mention tobacco water, cut 
tobacco leaves, kerosene emulsion, and air-slacked lime. The date 
of each application and the proportions used were noted, and the 
plants upon which the applications were made, examined daily and 
the number of insects found counted and compared with the number 
found upon other plants that had received no applications. We 
summarize our results as follows: 7 
A strong decoction of tobacco proved very efficient when frequently 
applied ; but its strength seemed to volatilize quickly in the sun. 
At least our figures indicated that little, if any, benefit came from 
the application after two days. Our decoction was made by soak- 
- ing tobacco leaves in cold water for twenty-four hours, when the 
water was poured off and applied to the plants by means of the 
garden sprinkler. 
We found the kerosene emulsion diluted with eight parts of soft 
water to be very eflicient, but its effects were little, if any, more lagt- 
ing than those of the tobacco water, and when frequently applied it 
evidently retarded the growth of the plants. 
We will here describe our method of making the kerosene emul- 
sion. Weused the same formula in all our experiments, so that 
whenever we have occasion to refer to it hereafter it may be under- 
stood to be precisely of the proportions noted here. We combined 
one gallon of kerosene oil, one gallon of water, and four pounds of 
common yellow bar soap, heating the mixture and stirring it occa- 
sionally until the mass became homogeneous, then stirring it con- 
stantly until it became thick by cooling. We found this preparation 
to be entirely permanent, and we were able to dilute it to any de- 
sired extent by the addition of rain water without the oil separating 
from the mixture before it could be readily applied to plants. 
Tobacco leaves cut fine, by passing them through a fodder cutter 
when placed about the plants of radish, had a marked effect in 
keeping off the flea beetle, the appearance of the leaves showing the 
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* Phyllotreta striolata (Fabr.). 
