484 



ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



on the .study of the conipo.sition of I'libber goods, with a view to draw- 

 ing up specifications for this chiss of material, and an investigation 

 of paint materials has been begun, including the preparation for some 

 extensive paint tests. 



As to the bulk of the work accomplished, the number of samples 

 examined for the various government departments showed a very 

 great increase over that of the preceding years, being the greatest 

 ever examined in an}^ one year since the establishment of the labora- 

 tory. The attached table shows the distribution of this work, ac- 

 cording to the character of the material examined and the department 

 for which the examinations were made. The character of the samples 

 varies greatly, but the larger number was under the classes of colors, 

 paints, and varnishes, and oils, fats, greases, and waxes. The greatest 

 increase in any one class of samples examined was in typewriter rib- 

 bons, of which 595 were tested as compared with 73 in the previous 

 year. The total number of samples examined during this year is 

 2,829. which does not include more than 3,000 pieces of apparatus 

 tested for the Bureau of Chemistry. This work is done under the 

 supervision .of P. H. Walker. 



Xumhrr of samijlcs of contract supplies analyzed. 



o Including Bureau of Engraving and Printing. 



b Including Bureau of Chemistry. 



NITROGEN DETERMINATIONS. 



A section in charge of T. C. Trescot is devoted entirely to nitrogen 

 work, which is especially important in the administration of the 

 food law, since the value and quality of a j^roduct frequently depend 

 largely on the nitrogen content, as in the case of dairy products and 

 cattle foods. Another important application of these data occurs in 

 the research work on cereals and the examination of the excreta of 

 animals, referred by the Pharmacological Laboratory of the Drug 

 Division in the course of experiments on metabolism. In all 10,.500 

 such determinations were made on .samples referred from the various 

 laboratories of this Bureau and from the Bureau of Plant Industry. 



