Chemicals for making insecticides used in the fight against crop pests and diseases have been made scarce by the war, both because of demands for them by war industries and the cutting off of foreign sources, says James R. Hile of the Acme White Lead and Color Works, Detroit, Mieh.-Arsenic, for instance, is hit both ways. About half of our arsenic in normal times came from Syveden, Belgium and Japan, all nofv shut off by the war, and great quantities are needed in the manufacture of khaki cloth, blankets, etc., and in glassmaking. It is also used in production of weed killers to replace chlorates now absorbed by the powder mills. Rotenone, an important organic insecticide, came largely from the East Indies, with about 40 percent coming from South America. Although the South American supply can be stepped up to perhaps 60 percent, it still leaves a severe lack. The principal source of pyrethrum was Japan, but the British African colony of Kenya can replace this loss if enough shipping space can be made available.