458 



ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



leaves little or no time for systematic research. The largest part of 

 the work of the laboratory has been the testing of miscellaneous 

 contract supplies and the preparation and modification of specifica- 

 tions. Work has been continued on the study of the composition of 

 rubber goods with a view to drawing up specifications for tnis class of 

 material, but the results so far obtained are not such as to justify 



Eroposing a specification. The investigation of paint materials has 

 een continued and a number of exposure tests has been begun. 

 Work has also been done on authentic samples of linseed oil, made 

 from domestic seed in cooperation with the American Society for 

 Testing Materials, and a specification for raw linseed oil made from 

 domestic seed has been adopted which it is believed is fair to both 

 producei' and consumer. Plans have been perfected, also, in cooper- 

 ation witli the American Society for Testing Materials, for a very 

 comprehensive series of white-paint tests. Considerable progress 

 has been made on the study of enamel-ware cooking utensils. The 

 quality of platinum laboratory utensils is of the utmost importance 

 to the chemist, and the great advance in the price of platinum in 

 recent years has been accompanied by a more or less marked deteri- 

 oration in the quality. Tliis laboratory has obtained very valuable 

 information concerning the properties of the different grades of 

 platinum, and while the work is not complete, the information is such 

 as to safeguard the interests of the bureau in issuing specifications for 

 and testing deliveries of platinum ware. As another result of this 

 study serious effort is bemg made by several manufacturers to im- 

 prove materially the quality of their ware. 



The laboratory made analyses of 2,309 samples for the various 

 departments. The attached table shows the distribution of this 

 work according to the material examined and the departments for 

 which the examinations were made. In addition to the samples 

 reported in the attached table over 4,200 pieces of apparatus were 

 examined for the Bureau of Chemistry. 



Number and distribution of samples of contract supplies analyzed in 1911. 



» Including Bureau of Engraving and Printing. 



s Including Bureau of Chemistry, 



