1120 Place the required amounts of acid and water in a glazed earthen ware jar, observing the usual precautions in the mixing. Complete all other preparations and be ready to make a hurried exit. Have the cyanid wrapped in a paper and drop it in the jar and instantly leave the room. Keep the quarters closed at least one hour. If several rooms are to be treated some ar rangement with slings should be devised for lowering the cyanid into the acid from the outside.
Both cyanid and are also employed for the destruction of rodents. In maritime quarantine the exhaust gas from gaso line engines or the funnel gas from burning coal are also em ployed, due to the large content of carbon monoxide present. For small rooms or infrequent treatment it is not practical.
Another substance of great value for this purpose is carbon bisulphid, but whose wide employment is limited owing to its inflammable and explosive qualities. Carbon bisulphid volati lizes rapidly and is fully as explosive as ether. The gas is heavier than air. It is best adapted to the treatment of clothes rather than rooms and is preferably employed in small air tight closets or chests. It should be allowed to volatilize in the pro portion of one pound per roo cubic feet. The container from
which it evaporates should be placed at the top of the enclosed space. It should be allowed to act for io to 12 hours.
Insect powders have some value, particularly those composed wholly or in part of dried pyrethrum flowers. These are burnt, or diffused through the air as a powder. The vapor or dust stupefies the insects so they fall to the floor and may be removed by sweeping. Pyrethrum is not injurious to man.
The body louse, because of its intimate relationship to man, cannot be altogether controlled by fumigation unless the clothing of all infected individuals is fumigated at the same time. For the delousing of clothing and bedding, physical agents give better results than fumigants, although in emer gency work circumstances will largely control ones' efforts. Streaming steam will kill both adult lice and nits in 20 minutes and dry heat for 20 to 3o minutes at 6o degrees C. will also destroy adults or nits. Simultaneous attention must be paid to lice on the person, particularly in the hair. The old standby of kerosene and vinegar is probably best for this purpose.