222 CJilorine Oas, a Rat Exterminator. [May, 



finely pulverized black oxycle of manganese, and poured over it a suitable 

 quantity of strong hydro-chloric-muriatic-acid. The floor-hoard was 

 then replaced. The efiPect of the chemical mixture of the black oxyde of 

 manganese and hydrochloric acid is to disengage in the cold that most 

 powerful, deodorizing, fumigating gas, chlorine. In common with all 

 gases, it gradually diffuses itself through the air, but having a greater 

 weight than atmospheric air, it accumulates at the lowest levels. The 

 tendency of the gas liberated, therefore, was to penetrate every space 

 between the wulls and ceiling, and it at last found exit in the cellar. 



It may be here stated that the quantity of gas so liberated can exert 

 no injurious effect upon the house or its inmates ; indeed the result is 

 rather beneficial than otherwise upon the general health. 



The chemical arrangement described had not been long in opera- 

 tion, when it became evident that something unusual was occurring in 

 ratdom. *' All night long, it would seem," says the narrator, " as if Bed- 

 lam had broken loose between the partitions of my house." Toward morn- 

 ing all had become quiet — the rats had vamosed, big and little, and for a 

 period of nearly three months not one was heard or seen on the premises." 

 We may add that, while the application of this remedy is exceedingly 

 simple, the materials for evolving the gas are very cheap ; indeed the 

 whole cost would be quite trifling. And for the purpose of making the 

 mode of obtaining this gas more plain we subjoin the following directions 

 for the benefit of those who may desire to prove its practical efficacy as 

 a rat exterminator ; 



Take one proportion of powdered black oxyde of manganese, and two 

 or three proportions of hydrochloric acid — generally called muriatic 

 acid — and mix them in an earthen or glass dish, and set the dish in 

 such position that the gas, evolved by the chemical action of this mix- 

 ture, may be directed to the quarters infested. 



The materials above mentioned may be found at almost any drug 

 store ; and whosoever has at any time inhaled a full draught of this gas, 

 will not be surprised that rats would turn in disgust from the domicil 

 through which it is, for the time being, diffused. 



We may remark that the gas will be evolved from this mixture when 

 cold, but if it is desired to liberate the gas more freely, a little heat may 

 be applied. As the editor of the Journal intimates, this gas is in no 

 wise injurious to the healthfulness of the house, as it is frequently 

 emploved to give sweetness and purity to the sick-room, and for purifying 

 damp and foul cellars ; and if it will furthermore aid us in expelling 

 rats from our dwellings and barns, its utility will be much more 

 generally appreciated. 



