INSECTS AND DISEASES 45 
This formula answers for 2000 cubic feet of space. 
For a larger or smaller house, increase or de- 
crease the amounts proportionately. Never 
forget, however, that this gas is a deadly poison 
in the most minute quantity, and handle it 
accordingly. 
Green fly, aphis, leaf-hoppers, and other small 
insects bother vines a little, mainly in the spring, 
especially if the weather happens to be very dry. 
All plants are liable to attacks by these insects, 
but those most often found to suffer are the 
climbing roses, English ivy, ampelopsis, honey- 
suckle, and all annual vines. 
The two main remedies for these pests are kero- 
sene or soap emulsions and some sort of tobacco 
solution. Tobacco is used in the greenhouse 
both in the form of a powder or as a decoction, 
when steeped in water. In the latter condi- 
tion it is especially effective on tender insects 
and is very convenient to use. When mixing 
it, always add a little dissolved soap, to make the 
mixture stick on the foliage better. If a little 
care is taken to get the solution into the very 
heart of the new growth, where the aphides are 
usually found in the greatest numbers, they will 
usually be done away with. Use a weak solution 
a couple of times in early spring. 
