272 INSECTS 



with about a dozen members. In 1907 there were 

 enrolled among the active and associated members, 

 most of them in official positions, no less than 211 

 names; and that does not include all of them. Of 

 foreign associates interested in the same line of work 

 there are forty-five, and that includes most of those in 

 official positions. In 1888 there were less than half a 

 dozen makers of pumps or machinery suitable for 

 insecticide work, while nozzles were difficult to obtain 

 and poor. At present there are numerous makers of 

 machinery and each of them presents a long line of 

 pumps, nozzles and fittings for applying insecticides 

 and fungicides. On the Pacific Coast the problems 

 were somewhat different from those of the Atlantic 

 Coast and the line of development in the production of 

 insecticides and spraying machinery was also different. 

 Fumigation with hydrocyanic acid gas, the lime and 

 sulphur and resin-washes are Pacific Coast contribu- 

 tions; the development of the arsenical sprays and the 

 mineral oil preparations are to be credited to the Atlan- 

 tic Coast, or at least to the territory east of the Rocky 

 Mountains, for much of the pioneer work with insecti- 

 cides was done in Illinois and Missouri, by Walsh 

 and Riley. 



In 1889, every ounce of kerosene emulsion was 

 home-made, and Paris green, London purple, helle- 

 bore, tobacco and pyrethrum were practically the only 

 insecticides on the market. There was whale oil soap 

 also, but expensive and an unknown quantity as to 

 its ingredients. Now there are a large number of 

 manufacturers throughout the country, producing com- 

 mercially every preparation that has proved useful in 

 the hands of experimenters, and chemists everywhere 

 are seeking to improve and cheapen the known combi- 

 nations or to devise new and more effective ones. Mis- 



