38 
THE COLORADO EXPERIMENT STATION 
applications for the destruction of scale insects and eggs of the 
brown mite, particularly in dry climates, like that of Colorado. It 
should be used only in the winter or spring, while the trees are 
dormant. The ingredients may be in the following proportions: 
Lump lime (good).20 pounds. 
Sulfur.15 pounds. 
Salt.10 pounds. 
Water.50 gallons. 
Slake the lime, preferably with hot water, in an iron kettle or 
a barrel, and while slaking, slowly add the sulfur and stir it in. 
Then boil over a good fire or by means of a jet of steam in about 
one half the required amount of water (25 gallons) for an hour or 
two, or until a dark red color is obtained. Then add the salt and 
boil for 15 minutes longer, strain, dilute to 50 gallons and apply 
while hot. Many are leaving out the salt and they seem to have 
just as good results. 
22 . PYRETHRUM, BUHACH, OR PERSIAN INSECT POWDER. 
This substance is a vegetable powder and is obtained by pul¬ 
verizing the dried blossoms of plants of the genus Pyrethrum. It 
may be obtained at almost any drug store, and is peculiar in its 
power to kill insects while it is not poisonous to the higher ani¬ 
mals. It may be used either wet or dry. If applied in water, use 
in the proportion of: 
Pyrethrum.1 ounce. 
Water.3 gallons. 
If applied dry, use pure and make a very light application, or 
dilute with flour and apply more freely. 
If thoroughly disseminated in the air of a room it will soon 
bring to the floor all the flies and mosquitoes therein. A good way 
to rid a room of flies is to make a thorough dusting of the powder 
through the room and then close the room tightly for the night. 
Then in the morning sweep up the flies and burn them. If they 
are not destroyed in this way after being stupefied, many will finally 
overcome the action of the powder and live. 
23. TOBACCO. 
Tobacco has long been used in one way or another for the de¬ 
struction of insects. Its chief use seems to be for the destruction 
of lice. When slowly burnt the smoke may be utilized for the 
destruction of lice on plants in greenhouses or window gardens. 
In the form of a fine dust it is often effectual in ridding plants of 
flea-beetles, and in the form of dust or stems is probably the best 
remedy we have for woolly aphis on the roots of apple trees. 
A decoction made by boiling tobocco dust or stems in water in 
