(oe) 
jars, it is a good plan to surround each jar by some protection. A 
section cut froma roll of building paper is effective. The paper 
naturally rolls into a tube and is very convenient for this purpose. 
The pieces may be laid together and tied when not in use, so that 
they will keep their shape. When all is ready, go out quickly, close 
the door, and carefully loosen the strings, allowing the bags to settle 
into the acid. The gas will very soon be given off and fill every 
portion of the house. It is colorless and smells and tastes like peach 
pits. A little of it is harmless but too much will cause death. <A 
small quantity will leak out of the house; avoid positions where it 
can be smelled. The time of exposure should be reckoned from the 





Fic. 3.—Violet house prepared for fumigation (original). 
lowering of the cyanide into the jars. When the proper time has 
elapsed, varying for different plants as previously stated, quickly 
open the ventilators from the outside, so that the gas can escape as 
rapidly as possible. It will all be gone from a large house, such as 
described in this circular, in half or three-quarters of an hour, and 
the ventilators may then be closed, if necessary. Next morning the 
material left in the jars should be emptied into a hole and buried. 
It is nothing but sulphate of potash, sulphuric acid, and water, having 
a little hydrocyanic acid gas in solution. The latter will soon disap- 
pear and the sulphuric acid will unite with lime in the soil, forming 
gypsum. 

