TOBACCO SMOKE. 
|! ■ 
\\e difficulty of reaching all the worms in a cabbage head by any 
jication of a powder or liquid, after the head is pretty well 
n, and especially after the worms have commenced to penetrate 
tade it desirable to find some vapor which might be easily ap- 
in a way to reach all the insects with destructive effect Ex¬ 
tents were consequently made—first with tobacco smoke. Three 
age worms were confined under a bell-jar, and exposed to the 
;e of a cigar for ten minutes. A full-grown worm was scarcely 
-11 affected. Both the smaller ones, a little over half an inch in 
h, were nearly lifeless, when removed from the jar. In a few 
i s, however, they had entirely recovered, and were apparently 
jured by their experience. Five individuals were next selected, 
ing from half an inch in length to full-grown specimens, and 
exposed to the smoke as before, for ten minutes, under a glass 
All except one of the largest were badly affected, the three 
; ler being apparently nearly dead. In an hour and a half the 
!i larger ones were crawling about, but two of the others were 
rently killed. In two hours more, however, all were crawling 
jt except one, and that showed evident signs of life, and prob- 
would have recovered in time. No experiments were tried with 
||r exposure, because, even if successful, it would be found im- 
jicable to apply tobacco smoke for a longer time in the field. 
SULPHUR. 
r some reason which I do not now remember, I thought it 
i while to try a single experiment with the fumes of sulphur, 
proved to be sufficient. The record is brief and conclusive:— 
sed two minutes; plant killed, worms uninjured. 
■ 
BISULPHIDE OF CARBON. 
e vapor of bisulphide of carbon was also used, not with any 
: 3tation of a practical application to cabbage plants, but to 
I ier test the hardiness of the worms. Two nearly full grown 
mens were placed under a bell jar of about a gallon capacity, 
about half a cubic inch of sponge was saturated with the fluid 
placed under the shade with the worms. The effects were ap- 
it in less than a minute, and in five minutes both the worms 
rolling about, disgorging a green fluid. When the shade was 
ved at the end of ten minutes the worms were not dead, 
sompletely torpid. In three-quarters of an hour they showed 
signs of life, and in four hours were evidently slowly recover- 
In three hours more they had completely regained their 
, ity and crawled away. Again, three worms, one half grown, 
die others of full size, were exposed under a smaller jar for 
i' ame length of time. When the glass was removed, none of 
showed any sign of life. In three-quarters of an hour, liow- 
the young one was crawling about and the old began to move, 
in two hours longer, all had recovered and disappeared. 
