INSECTICIDE AND FUNGICIDE BOARD. 369 



titles "The Preparation and Properties of Lead Chlor-arsenate — 

 Artificial Mimetite," and "The Arsenates of Lead," by the American 

 Journal of Science and the Journal of the American Chemical Society. 

 A third paper on this subject is in course of preparation, which will 

 deal further with the chemistry of the arsenates of lead and the 

 arsenates of calcium. A considerable number of new lead arsenates 

 have been prepared and their properties studied, and this study is 

 now being extended to the arsenates of calcium. 



A method has been perfected for the determination of arsenic in 

 arsenates and the various insecticidal and fungicidal mixtures con- 

 taining arsenates, and has been published in the Journal of Industrial 

 and Engineering Chemistry under the title "The Reduction of As v 

 to As jii by Cuprous Chloride and the Determination of Arsenic by 

 Distillation as Arsenic Trichloride." 



The investigation started some time ago to discover a chemical 

 method of determining stems in insect powder and establish standards 

 ior insect powder, has been continued and has been extended during 

 the past year to include a study of the process of manufacturing 

 fnsect powder and the composition of the raw material, as well as 

 the finished insect powder prepared under known conditions. It is 

 hoped that from a study of the numerous figures that have now 

 been obtained, satisfactory standards for insect powder can soon 

 be established, which will be of great service in recognizing adult- 

 eration or misbranding of this class of goods. 



In cooperation with the Bureaus of Entomology and Plant Industry, 

 the entomologists and plant pathologists of the Board have under- 

 taken an investigation of the comparative merits of dust and liquid 

 sprays in the control of insects and diseases. Especial attention will 

 be given to tests of finely ground sulphur in combination with 

 arsenate of lead, with a diluent, as finely ground lime or gypsum. 

 A number of investigations have been carried out by the entomologists 

 of the Board to obtain information necessary in connection with the 

 enforcement of the act, as for example, a study of the action of 

 various chemicals on soil insects; further investigations were made 

 of the value of different pyre thrum powders, tobacco powders, 

 nicotine solutions, etc., when used as sprays, dusts or fumigants. 

 Experiments have been made to determine the action of potassium 

 cyanide and other substances in the control of insects and plant 

 diseases when injected into the tissues of plants. 



The scientists of the Board working under the direction of the 

 Bureau of Animal Industry have made an investigation relative to 

 the amount of sulphur present in normal coal-tar creosote oil, such 

 oils being the basis for the so-called coal-tar creosote dips. Investi- 

 gations relative to the efficacy of certain preparations in the treatment 

 of mange, especially of the demodectic variety, and in the treatment 

 of certain parasitic worm infestations, were of special importance 

 in connection with the enforcement of the law. 



