No. 6. 



A Method for destroying Weevils, Moths, Sfc. 



179 



For the Farmers' Cabinet. 



A 3Iethod for Destroying Weevils, Moths 

 aud other insects injurious to Wheat. 



JNIr. Editor, — Having read in your No- 

 vember Number your article on insects de- 

 stroying- corn and wheat, and Dr. Harris's 

 letter on the same subject; it brought to my 

 mind an article which I had read in the 

 Atinales de Roville, an excellent book from 

 the pen of the late Matiiieu de Dombasle. 

 Although, in m}^ opinion, it is useful to us 

 farmers to be able to identify the enemy, 

 still WG are not much benefited, unless fur- 

 nished with a means of destroying him. I 

 have therefore translated and herewith send 

 you the abovementioned article. If you 

 think it may be of any use, you may insert 

 the whole, or part of it in your paper. B. 

 Dec. 12th, 1846. 



" A multitude of means for destroying in- 

 sects that devour wheat in granaries, have 

 been suggested at different times; but it 

 must be acknowledged that we are still in 

 want of an easy and economical process, 

 which should fulfil with certainty the in- 

 tended object, without presenting objections 

 of a nature precluding its constant and habit- 

 ual use. I have some hope of these requi- 

 sites being found united in the method I am 

 going to describe, which has been communi- 

 cated to me by an enlightened and trustwor- 

 thy farmer who lives in my neighbourhood, 

 and who has been completely successful in 

 its application. 



" The idea must have occurred frequently 

 of applying sulpliurous acid gas — the vapour 

 which escapes from burning brimstone — to 

 the destruction of insects injurious to grain; 

 we know, indeed, with what promptitude 

 this gas occasions the death of all insects 

 exposed to it: the only difficulty might be 

 in finding a simple and easy way of tho- 

 roughly penetrating with this gas the mass 

 of infested grain. Should there be merely 

 brimstone burned in the room where the 

 grain is stored, it is probable that only the 

 surface of the heap would be penetrated at 

 a very inconsiderable depth: it would be- 

 sides require the production of an enormous 

 quantity of gas, as the whole contents of the 

 granary must be filled with it, to obtain 

 even such an incomplete effect. The above 

 mentioned farmer has contrived an ingeni- 

 ous way of applying the gas, which I think 

 will answer every purpose with ease and 

 economy. He proceeds as follows: — he 

 makes use of two empty casks, containing 

 each two or three hectolitres,* which are 



An hectolitre is equal to 23 gallons English mea- 



placed on two joists ten or twelve feet long, 

 laid on the floor as they are usually disposed 

 in a wine cellar. This apparatus should be 

 placed in the granary so as to have sufficient 

 space to circulate all round. The casks 

 have an opening a little larger than a com- 

 mon bung-hole. Through this opening the 

 cask is filled with sulphurous gas, by burn- 

 ing a brimstone match, in the same wav as 

 coopers do for wine casks.f The wheat is 

 then by means of a funnel poured into the 

 cask until completely full, and it takes the 

 place of the gas. While the match is burn- 

 ing in one cask, the other is filled with grain 

 and being rolled to the extremity of the 

 joists, which ought to be raised one foot 

 above the floor ; tiie wheat is poured out on 

 the floor, when it is raked in a heap to one 

 side. Two men working in this way, may, 

 in a few hours, saturate with sulphurous eras 

 a considerable quantity of grain; for this 

 operation is about as speedy as that of mea- 

 suring wheat. 



" It is easily understood that, in this pro- 

 cess the grains of wheat separating from 

 each other when falling through an atmos- 

 phere of sulphurous gas, are impregnated 

 with it all over, and that it is impossible for 

 one single grain in the whole not to be 

 reached by it. The air which fills the in- 

 terstices between the grains is so impreg- 

 nated with this gas, that no insect can pos- 

 sibly live many seconds in it. 



" This method seems to me to insure the 

 destruction of all insects that may be con- 

 tained in wheat, whether they are in ihe 

 state of larva or in the state of perfect in- 

 sect ; but I am not as certain that the eggs 

 shall lose the faculty of hatching. This 

 question will demand new researches. At 

 any rate, admitting that the eggs might 

 withstand the action of the gas, the per- 

 formance of this process is so easy and re- 

 quires €o little expense, that even if it had 

 to be repeated when new insects should 

 have hatched, the inconvenience would be 

 trifling; and the evil would be cut in the 

 root by destroying at once a whole genera- 

 tion, as no new eggs could be produced. 



"To take off the smell that the grain 

 might have contracted by this operation, it 

 will be sufficient to stir two or three times 

 in the space of a few days, the heap of sul- 

 phurated v.heat, acid sulphurous gas being 

 eminently volatile; and the farmer who 



fThis operation is performed by fastening the match 

 at the end of a wire which is introduced at the bung- 

 hnlc. The match must be placed as low as may be 

 without danger of setting fire to the cask. The floor 

 of granaries in France are generally laid with bricks. 

 On board floors some precautions should be used. 



