56 INSECTS INJURIOUS IN 1902. 
effective remedy is treatment with hydrocyanic gas, but this is so 
dangerous an agent, being fatally poisonous to human beings, that 
the Entomologist would only advise its use under most extreme 
precautions. Cir. 46, Second Series from the United States De- 
partment of Agriculture, Division of Entomology, describes this 
process in detail. Another gas, also poisonous, but not so deadly, 
bisulphide of carbon, can be effectively used where the insect in- 
fests small rooms which may be completely sealed. An Italian 
worker says that one part of the liquid bisulphide to every 10,000 
parts of atmosphere, will kill all and every insect the gas comes 
in contact with. The writer has practically corroborated this in 
some work, as yet unpublished; but it should be noted that to do 
this the liquid must be of the best quality, and not the cheapest 
grade, which leaves a residue upon evaporation. 
The Department cf Agriculture recommends one part. of 
bisulphide to every 1,000 cubic feet of room space to kill Roaches. 
Another remedy suggested is burning Pyrethrum in a closed 
room. The writer has used a phosphorous paste with fairly 
good results, placing small bits of the paste about the sink in the 
kitchen and other places frequented by this pest. . 
Firms which sell bakers’ supplies generally carry in stock a 
patent powder, said to be extremely effective in this direction. 
A family known to the Entomologist have driven Roaches away — 
or exterminated them by the persistent use of powdered borax in 
the kitchen. This was dusted in all cracks and crevices about 
the room daily (particularly in the evening) for two weeks, care 
being taken to use it liberally along the entire length of mop 
board wherever there was a crack large enough to hide a Roach, 
and its use was persisted in for some time after all insects had 
apparently disappeared. 
This insect at one time was called Blatta germanica; see 
Fig. 49. 
CARPET BEETLES, CARPET “MOTHS: BUBEAEG 
MOTHS. 
Anthrenus scrophulariae, Linn. 
Attagenus piceus, Oliv. 
Specimens of both thé above carpet pests have been sent to 
