CHAP. XVIII.] PESTS OF STORED PRODUI rs 165 



•ugh drying should be sufficient to kill off .ill insect life and the 

 subsequent storage to maintain it free ol pests. It must be remem- 

 bered that, in drying grain in the sun, it must be spread out evenly 

 and thinly so that every grain may be exposed to the sun's rays and 

 heat ; it is of little use to pile grain up in heaps, as the individual 

 grains at the bottom of the pile will posed to the sun, so 



that the insects in them will not be killed and will subsequently 

 int'eet the rest. For the storage of grain in villages, the use of 

 large glazed earthenware jars, which can be tightly closed with a 

 stopper and this thickly and tightly luted with clay, will he found 

 . > i n is thoroughly dried in the sun before 

 placing it in the jars and scaling it up, which will normally be done 

 in dry weather, not only should it remain free from insect attack, 

 but danger of damage by mould should be eliminated to a large 

 extent. 



Fumigation, which is only recommended in the case of godowns 

 or stores on a fairly large scale, maj be accomplished by the aid 

 either of Carbon Bisulphide or Hydrocyanic Acid gas. Both are 

 dangerous and poisonous substances and should only be used under 

 strict and competent supervision. The former is inflammable and 

 violently explosive; the latter is inert in these respects. 



Carbon Bisulphide is a heavy, colourless, oily liquid, which 

 rapidly evaporates into a colourless gas heavier than air, both 

 liquid and gas exhaling an extremely unpleasant and characteristic 

 smell, and being poisonous if inhaled. The liquid is inflammable 

 and the gas is violently explosive when mixed with air in the 

 present e of tire. The liquid must be kept in stoppered (not corked) 

 bottles and should not be exposed to direct sunlight or stored in 

 any place where it is liable to be heated or to leak or to be upset or 

 spilt. Carbon Bisulphide must never be opened or taken near 

 a light or fire of any sort, not even a lighted pipe, cheroot or 

 cigarette, nor should it ever 1> used ma place to which 



unauthorized persons may h. For fumigation it is 



simply poured on to the grain to be treated at the rate of about one 

 ounce for every fifteen cubic feet or, in the case oi large bins 

 full of grain, about one-and-a-half pounds of fluid to each 

 ton of grain. As the gas is heavier than air, if the liquid is poured 

 ■ the grain, it will s,,ak down ami through it. After twenty-four 

 hours, during which no light or tire must be allowed anywhere near 

 the place where the treatment is being carried out. itaclc 



may be opened, again in the complete absence of lire in any shape, 

 any gas which may be present allowed to escape, and the grain 

 removed and at on< 1 red to permanent storage. It mi; 



clearly understood that treatment by fumigation in this way will 



