76 Scientific Intelligence. [Jan. 



Article XIII. 



SCIENTIFIC INTELLIGENCE, &C. 



I. — Method of destroying Mice Sfc, in their lurking places. 

 {Ann. de Chirn. xlix. 437.) 



M. Thenard, in 1832, submitted to the Academy of Sciences apian 

 for destroying noxious animals, when they have taken refuge in their 

 hiding places. The instrument of destruction is sulphuretted hydro- 

 gen, which he had remarked to be peculiarly deleterious to animal 

 life. Animals when allowed to breathe the pure gas fall down as if 

 struck with a bullet. Even when considerably diluted with atmos- 

 pheric air, the effects are deadly. A horse dies in less than a minute, 

 in air containing ^ of this gas. A dog of moderate size is speedily 

 killed in air containing ^ while a greenfinch expires in a few seconds 

 in air possessing ?~r of sulphuretted hydrogen. Influenced by these 

 facts, the French chemist proposed the employment of this gas to 

 several individuals for the purpose of extirpating noxious vermin, 

 but his suggestions being treated with indifference, he determined to 

 put the method in practice by his own experiments. 



His first trial was in an apartment infested by rats, which shewed 

 themselves occasionally during the day, and at night were actively 

 engaged in plundering a chest of oats, to which they had access 

 through an aperture of their own formation. The holes by which 

 theji retreated amounting to 18 in number, Thenard adapted to each 

 of them in succession retorts capable of containing half a pint mea- 

 sure, by introducing the beak of the retort and filling up the interval 

 round its neck with plaster. Sulphuret of iron was deposited in the 

 retort, formed from a mixture of iron filings sulphur and water, and 

 dilute sulphuric acid was introduced by means of a tube placed in 

 the tubulure. The sulphuretted hydrogen was disengaged with 

 great rapidity, and in a few minutes not a rat remained alive in the 

 building. His next experiment was in an old abbey where he was 

 equally successful, and having opened up part of the wall he found 

 many dead rats. He recommends the application of this method to the 

 destruction of moles, foxes, and all animals which cannot be extirpated 

 by the usual means. Thenard then gives popular directions for the 

 formation of the materials required to produce the gas. 



Mix 4 parts of iron filings, 3 parts flowers of sulphur in a mortar 

 with a pestle. Place the mixture in a convenient vessel, and 

 moisten it with 4 parts of boiling water, stirring it with a piece of 

 wood or glass. Add gradually afterwards 4 parts more of water, and 

 introduce it into the retort. Pour upon the mixture common oil of 

 vitriol diluted with five times its volume of water, and continue to 

 add it gradually till the effervescence ceases. Should any of the gas 

 escape into the apartment and occasion inconvenience, it may be re- 

 moved by dropping a little sulphuric acid upon bleaching powder. 

 The holes should be closed immediately, to prevent the disagreeable 

 effects of the putrefaction of the carcases of the animals which have 

 thus been destroyed. 



