154 
Stock Sohition 
Hard soap (preferably "Ivory" or "Tak-a-nap") i pound 
Soft water i .gallon 
Crude carbolic acid i pint 
Dissolve finely sliaved soap in boiling water, add the carbolic 
acid, and churn as for kerosene emulsion. For use, one part of the 
stock solution is diluted with thirty to forty parts of water. 
Hellebore Decoction 
For use against root-maggots, this decoction is prepared by steep- 
ing two ounces of white hellebore in one gallon of hot water for .^o 
minutes. For insects infesting the foliage, one ounce of hellebore 
to two gallons of water is suf^cient. Hellebore very soon loses its 
insecticidal properties by exposure to the air, and care should be 
taken to obtain only such as is known to be fresh. 
Insect Powder (Pyrethrum. or Buhach) 
P3Tethrum, or insect powder, as this insecticide is commonly 
called, is of special value for killing certain kinds of insects, and it 
has the advantage of being harmless to human beings and the higher 
animals. On the other hand, its expense prohibits its use on a com- 
mercial scale, and it quickly loses its virtue when exposed to the air. 
If used in a dry form it should be mixed with twice its weight of 
common flour, and kept in a tightly closed vessel for 24 hours before 
using. It may be applied with a dust sprayer or some sifting appa- 
ratus. A decoction of pyrethrum may be made by mixing one ounce 
of the powder with enough water to form a thin j)aste and allowing 
it to stand several hours, after which sufficient water should be added 
to make two gallons. This is less effective than the dry powder. 
In purchasing pyrethrum, only hermetically sealed cans of it are 
safe, for the reason already given, but if they can not be obtained 
care must be taken to buy only an absolutely fresh article. 
Tobacco Decoction and Nicotine Preparations 
Tobacco decoction, altho not so effective as some of the above- 
mentioned contact insecticides, is still usedby many for killing soft- 
bodied insects, such as plant-lice. It is prepared by steeping tobacco 
stems in hot water at the rate of one pound to two to three gallons. 
More reliable than the above are \'arious commercial prepara- 
tions which likewise have nicotine as their active principle. (See 
page 159.) 
