432 THE FARMERS' HANDIiOOK. 



Fumigation with Liquid Carbon Bisulphide. — Perhaps of the two methods 

 of fumigation particularised above, treatment with carbon bisulphide is the 

 cheaper and easier. The gas given off by carbon bisulphide is very inflammable, 

 and care should be taken that no tires, lights, or lighted pipes or cigarettes 

 are near when handling the liquid or fumigating, but the substance may be 

 used with perfect safety if proper precautions are observed. Neither carbon 

 bisulphide nor carbon dioxide, if used as directed, will affect the quality of the 

 maize for seed or food. 



The maize may be fumigated in bags under a tarpaulin in lots of twelve to 

 twenty bags at a time, and this method is quite effective, but if an empty 

 galvanised iron water tank is available for use as a receptacle, so much the 

 better. If the grain is to be fumigated in bigs, place about fifteen bags side 

 by side on a tarpaulin or canvas sheet, and into the top of each bag pour 

 one to two fluid ounces of the liquid carbon bisulphide. Fold the sides of 

 the sheet over the bags tightly and so as to overlap, and cover the whole 

 with bags or another tarpaulin to further help keep in the fumes. A 

 " tryer " (sampler) serves as a useful funnel for running in the liquid, the 

 heavy fumes of which sink do » n tn rough the grain. Each lot of bags should 

 be exposed to the fumes for not longer than twenty-four hours. 



Fumigation should be carried out, if possible, on a warm day — say with a 

 tempera' ure of 70 deg. rah , as at a temperature below 60 deg. Fah. the 

 fumes become less effective. The bulk of the weevils will be killed by 

 this process, but the ba^s should be inspected every two months, and if they 

 show signs of reinfestation they should be given further treatment 



The advantage of using an emp r y water >ank as a receptacle for the maize 

 is that it can be made to hold in the fumes far more effectively than a tar- 

 paulin cove>, as th>- lid can be closed very tightly if a ring of rubber tubing 

 or a bag is placed under it and weights pi teed on top. For this reason less 

 of the liquid may be used. One ounce to every four bags of maize (that is, 

 to aboot every fifteen cubic feet of space in the tank) will be sufficient. After 

 twenty four hours' treat men 1 remove the lid temporarily to allow the fumes 

 to escape. 



Commercial carb >n bisulphide costs Is. 6d. per lb. if purchased in small 

 quantities, but it may be purchased more cheaply in 1-gallon tins, and more 

 cheaply still if a number of such tins are bought at a time. One gallon will 

 be easily sufficient to fumigate all the maize grown on the average farm in a 

 season. 



Fumigation with Carbon Dioxide Gas. — If it is desired to fumigate maize 

 by means of carbon dioxide gas it is essential that a galvanised iron tank be 

 used as a container. The yas is passed slow ly in through the top of the tank 

 by means of a rubber tube connected with an ordinary cylinder of the gas, 

 such as is easily procurable from v arious firms. The cylinder should be placed 

 on a weighi g mach ne, and the weight noted, and then 1 lb. of gas allowed 

 to flow into the tank for every 12 bushels of grain. The contents of the tank 

 can e estimated at 1° bu-hels of grain to 100-gallons capacity, so that a 

 500-gallon tank will h Id twenty bags (60 bushels) of shelled maize, and 

 therefore (whether full or not) should have lb of gas. The lid of . the tank 

 can be ieft off, as the carbon dioxide gas is heavier than air, and if it is 

 adm t ed slo ly (at th rate of 1 lb. in three minutes) it will push the 

 air up and out of the n an! ole as it sinks to the bottom. A lighted candle 

 held in the tank above the grain should go out for lack of oxygen. When 



