HARVESTING AND STORAGE 497 



granary from the standpoint of insect ravages should be built chap. 

 at some distance from the other buildings and made as nearly XI. 

 vermin proof as possible, the doors should fit tightly, the 

 windows covered with wire gauze, the floors, walls and ceilings 

 should be smooth, so as not to afford any lurking place for 

 insects, and it would be well to have them oiled, painted or 

 white-washed ; a coat of coal tar has been strongly recommended 

 for the latter purpose. 



" You are, undoubtedly, already aware that kiln-dried 

 mealies are but little attacked by weevils ; however, this method 

 has many disadvantages. 



" If the mealies have already been attacked by weevils, the 

 following methods may be employed, which will depend largely 

 upon the means at hand, as well as other conditions. The 

 grain is put into some air-tight bin or barrel, such as may be 

 at hand, and carbon bisulphide is applied. This chemical is 

 a colourless liquid with a strong, disagreeable odour, vaporizes 

 rapidly, is highly inflammable, explosive and poisonous. The 

 vapour is about two and a half times heavier than air and, 

 consequently, the liquid should be placed at the top of the 

 bin. For large masses of grain, from I lb. to \\ lbs. is used 

 to a ton of grain ; for smaller masses, I oz. is sufficient for 

 100 lbs. of infested matter. The bins are rendered as air- 

 tight as possible, and the liquid poured in into an open dish, 

 which is placed upon the grain. The infested grain is gener- 

 ally subjected to this treatment for 24 hours, but may be 

 exposed much longer without harming it for milling purposes ; 

 if not exposed for more than 36 hours, its germinating 

 power will not be impaired nor is it rendered unfit for feeding 

 purposes. 



"The greatest care should always be taken with this 

 chemical, as the vapour is explosive and a lighted pipe or 

 cigarette may be sufficient to cause a disastrous explosion. 

 I am quite sure that you will find carbon bisulphide the best 

 method for the purpose, as it is largely used in other countries 

 with universal success." 



469. Rats and Mice in Maize Stores. — Rats and mice are 

 as troublesome in South Africa as in other grain-producing 

 countries. Numerous remedial measures have been recom- 

 mended from time to time, in the Agricultural Journals of the 

 several Colonies, but perhaps none of them is more efficacious 

 than the old-fashioned cat or a good trap. 



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