BUKEAU OF CHEMISTRY. 593 



Besides making analyses of insecticides and fungicides for other 

 bureaus of the department when requested, this laboratory is also 

 charged with the chemical examination of insecticide and fungicide 

 samples (other than cattle dips and related products) for the Insecti- 

 cide and Fungicide Board in connection with the enforcement of the 

 insecticide act of 1910. 



During the year 405 samples were analyzed, many at the request of 

 other bureaus, as follows: 



Bureau of Entomology 40 



Bureau of Plaut Indiictry 25 



Other laboratories and divisions of the Bureau of Clieuiistry and miscel- 

 laneous 22 



Insecticide and Fungicide Board : 



Domestic samples, official 259 



Domestic samples, unoflicial 34 



Foreign or import samples 25 



318 



Total 405 



Of the 259 official samples examined for the Insecticide and Fungi- 

 cide Board, each representing interstate shipments of insecticides 

 and fungicides. 131, or a little over 50 per cent, were recommended 

 for prosecution, due to their being adulterated or misbranded, or both, 

 under the insecticide act of 1910. Of the 25 foreign or import samples 

 14, or 56 per cent, were recommended to be detained at the port of 

 entry for the same reason. 



Numerous other products were examined, such as vegetables, fruits, 

 foliage, and plants which had been treated with insecticides and fungi- 

 cides, fruits, hops, and other materials used in the preparation of 

 foods which may have been affected as a result of tlie application of 

 insecticides, etc. An investigation relative to the toxic effect on fruit 

 trees of certain elements, notably copper and arsenic which may accu- 

 mulate in the soil as the result of using compounds containing these 

 substances as sprays, has been under way for two years. The chemical 

 work in connection with this investigation is now practically com- 

 pleted. A study of the solubility of Paris green in water is being 

 carried on for the Insecticide and Fungicide Board in cooperation 

 with members of the Bureau of Plant Industry and Entomology. 



Methods for the analysis of lime-sulphur solution, Bordeaux mix- 

 ture, Bordeaux lead arsenate paste, and various insecticides used for 

 household pests have been given especial attention and accurate meth- 

 ods of analysis have boon developed. About 300 to 400 individual 

 determinations of the constituents of some of the common insecticides 

 have been made in collaboration with other chemists of the Associa- 

 tion of Official Agricultural Chemists during the course of a study 

 of improved methods of analysis of these products. 



Orchard tests with numerous insecticidal materials have been con- 

 tinued during the year to determine the cause of the injurious effects 

 of such materials on foliage and to discover some way of overcoming 

 the difficulty or some new effective compound tlial may be used on 

 such tender foliage as the peach without causing injury. 



Cattle Food and Orain Ikvestioation LAnoRATour. 



The laboratory considered during the year a total of 1.2.1,T sam- 

 ples, requiring approximately 7,800 separate determinations and in- 



70481°— AQB 1912 38 



