MISCELLANEOUS 223 



oxide in a suitable apparatus, and force the vapours by means 

 of a pump into the ants' nest. The vapour of arsenious oxide 

 is intensely poisonous, and as it cools it impregnates the 

 workings and their contents with a sublimate, which would 

 be fatal to any insect which might escape the effect of the 

 fumes and afterwards eat of the stores within the nest. An 

 apparatus designed for performing this operation has been 

 constructed. The material supplied with the machine consists 

 of about 11 per cent, of sulphur and 89 per cent, of arsenious 

 oxide, intimately mixed together. Arsenic, generally as 

 sodium arsenite, is the basis of many preparations for the 

 destruction of ants or preserving wood, <fec., from their 

 attacks. 



Another important use of arsenic is for poisoning locusts. 

 The plan adopted is to spray the grass or other vegetation in 

 the neighbourhood of a swarm of " voet-gangers " with a 

 solution containing 



Arsenite of soda . . . . ' . . 1 lb. 

 Sugar . . . . ; . . . 1 lb. 

 Water . . * 8 to 12 gallons 



The grass so sprayed, if consumed by the locusts, soon poisons 

 them, or, if not, it quickly dies and dries. If eaten by cattle 

 or sheep soon after spraying injury might result, but after a 

 few showers of rain the arsenic is to a great extent washed off 

 into the soil. Even if no rain falls the danger of cattle eating 

 the poisoned grass is not great, as after a few days the grass 

 dies and withers, and, except under stress of hunger, would be 

 rejected by the animals. The poisoned insects are often eaten 

 by poultry, locusts, birds, &c,, and though they contain con- 

 siderable quantities of arsenious oxide (in one sample we 

 found 0-219 per cent, in the dried insects) they do not appear 

 to do much harm to the birds. Nevertheless animals should 

 be kept from access to the sprayed locality until after several 

 showers, and the poisoned insects should be supplied in small 

 quantities only, if at all, to poultry, <fec,, as there is undoubtedly 



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