THE NATIONAL NURSERYMAN 
179 
After the buds are dried they are placed in the fumigating 
box which will clear the bud sticks of all injurious insect pests. 
The fumigation of buds, when properly done, is a most effi¬ 
cient and practicable way of keeping nursery stock free from 
injurious insects. 
The fumigating box is 4 ft. long, 2 ft. wide and 2>^ ft. 
high, inside measurements. The walls of the box consists of 
three thicknesses of lumber, each layer running in a different 
direction. The spaces between the boards are filled with a 
preparation of tar, which helps to keep the box air-tight. 
Ordinary building paper is placed between each layer of 
boards. Around the edges of the lid there are several layers 
of canvas which helps to keep out the air. The chemicals 
which is not dangerous. As soon as the cyanide is dropped 
in the acid and water, there is a bubbling and sizzling similar 
to that produced by a piece of red hot iron in cold water. 
The result of this chemical action is hydrocyanic acid gas, 
which is known in liquid fonn as prussic acid. Hydrocyanic 
acid gas has an odor somewhat similar to that of peach pits, 
but do not try to test it because if some of the gas is inhaled it 
will cause instant death. Plants are less injured by a short 
exposure to a relative large amount of gas than by a long 
exposure to a relative small amount, and also that a stronger 
dose in shorter time is more destructive to the insects affecting 
the tree. The resisting power of a tree is dependent largely 
upon the open and closed condition of the breathing pores, the 
used for generating hydrocyanic acid gas used in fumigation 
are: 
1. Fused cyanide of potassium. 
2. Sulphuric acid. 
3. Water. 
Cyanide should be guaranteed 98-99 per cent, which is 
practicably chemically pure. Do not use cyanide much 
below this strength. The best grade of commercial sulphuric 
acid, with a specific gravity of at least 1.83, should be used. 
A grade known as “chamber” acid used ordinarily in the 
manufacture of fertilizers will not do, and under no circum¬ 
stances should it be employed. Water from any source will 
suffice, the only requisite being that it should be clean. In 
combining the chemicals, first measure the acid in the glass 
beaker marked “ounces” on the side, and put it in any con¬ 
tainer such as an earthenware crock. Second, measure water 
in the same beaker and pour it on the acid. Third, drop in 
the cyanide, wrapper and all, close the door quickly and leave 
the desired length of time. When water is poured into the 
vessel with sulphuric acid, some heat and fumes are given off. 
peculiarit,ies of the cell contents and the temperature of the 
enclosures (box). Use from 0.05 to .1 or .105 grams of 
cyanide of potassium per cubic foot of the air space enclosed. 
Expose about half an hour. 
Immediately after the fumigation is over, the buds are 
taken out and sprinkled with water. Then the buds are 
wrapped in bundles with wet sacks. Much precaution must 
be taken here, because if the buds are not dampened and 
cooled quickly they are likely to spoil. The buds are put 
into the ice box which contains about 700 lbs. of ice. The 
buds generally remain here from one to twelve hours or more 
in order that most of the heat might be removed. The bud 
sticks “plump up” while in the ice box, but there is no danger 
of them water-logging as in the case of the “Bucket Method.” 
The lower the temperature the better the success with the 
buds. Always keep the box full of ice. Buds can be kept a 
week or more by this method without any signs of damage, 
but with the other methods it was impossible to keep the 
buds in good shape for any length of time. 
The ice box is 5 ft. long, 3 ft. wide and 3 ft. deep, inside 
measurements. On the outside of this box there are two 
