14 
ter with the poisonous fumes generated with potassium cyanide and 
sulphuric acid. 
The outfit—The tents are made of blue or brown drilling or 8-ounee 
duck and painted, or oiled with linseed oil, to make them as near air- 
tight as possible. They are placed over the trees by hand or with poles 
in case of small trees, but with trees over 10 feet high some sort of a 
tripod or derrick is used. The outfit for medium-sized trees—tent and 
derrick—will cost from $15 to $25. A tent for trees 26 feet tall by 60 
feet in circumference costs as much as $60. 
The chemicals.—Commercial fused potassium cyanide (costing in bulk 
40 cents per pound), commercial sulphuric acid (at 34 cents per pound), 
and water are used in generating the gas, the proportions being 1 
ounce by weight of the cyanide, slightly more than 1 fluid ounce of 
the acid, and 35 fluid ounces of water to every 150 cubic feet of space 
inclosed. 
The method.—The generator, which may be any glazed earthenware 
vessel of 1 or 2 gallons’ capacity, is placed within the tent under the 
tree and the water, acid and cyanide, the latter broken up, put in in 
the order named, after which the operator withdraws from the tent. 
The tent is allowed to remain on the tree for one-half hour for large 
trees or fifteen minutes for small ones. The treatment is best made 
on cloudy days, early in the morning, late in the evening, or at night. 
Bright, hot sunlight is liable to cause injury to the foliage, which, 
however, may be largely avoided by using tents of dark material or 
painted black. 
Three or four men can operate six tents at once, and the expense 
under such conditions, not counting the cost of the outfit, need not be 
more than 10 cents per tree. 
REMEDIES FOR SUBTERRANEAN INSECTS. 
Almost entire dependence is placed on the caustic washes, or those 
that act externally, for insects living beneath the soil on the roots of 
plants, including both sucking and biting insects, prominent among 
which are the white grubs, maggots in roots of cabbage, radishes, 
onions, ete., cutworms, wire-worms, apple and peach root-lice, the 
grape phylloxera, and many others. 
The insecticide must be one that will go into solution and be carried 
down by water. Of this sort are the kerosene emulsions and resin 
wash, the former preferable, the potash fertilizers, muriate and kainit, 
and bisulphide of carbon. Submersion, wherever the practice of irri- 
gation or the natural conditions make it feasible, has also proven of 
the greatest service against the phylloxera. 
Kerosene emulsion and resin wash.—Either the kerosene and soap 
emulsion or the resin wash, the former diluted 15 times and the latter 
at the strength of the winter mixture, are used to saturate the soil 

