A METHOD OF FUMIGATING SEED. | | 3 
When this apparatus is used for fumigation, the seeds, contained 
‘in either a cloth bag or an open vessel, are placed in the chamber, and 
the requisite amount of sodium or potassium cyanid in a small 
beaker is so arranged that the neck of the dropping funnel extends 
down into the Wekicer (fig. 1, f). The cover is then clamped on and 
‘the chamber exhausted. In extr acting the air from the chamber, the 
suction is continued until the gauge registers 30 inches or more- 
| that is, the air in the chamber is exhausted until the pressure is the 
/ equivalent of some fraction of an inch of mercury. The suction 
is then cut off by means of the gas cock, and the required quantity 
of diluted acid, which has been previously placed in the bulb of the 
Fig. 2.—Air pump (a) and fumigation chamber (6) used in the experiments described in this bulletin. 
dropping funnel, is allowed to flow slowly upon the cyanid in the 
beaker within the chamber. The hydrocyanic acid is thus prepared 
in the chamber and no trace can get out. After the seeds are exposed 
to the gas for the required time, the stopcock of the dropping fun- 
nel is opened to let the air into the chamber. As the discharge 
pipe of the air pump extends outside the building, the mixture 
of hydrocyanic acid and air can not escape into the room. As 
soon as convenient, the stopper and funnel are removed and, by 
means of the air pump, air is sucked through the chamber, thus 
washing the hydrocyanic acid out of the chamber before the cover 
is taken off and the seeds removed. In the experiments described 
