BUREAU OF CHEMISTRY. 



595 



The investigation of paint materials and the work of inaugurat- 

 ing a very comprehensive series of white-paint tests in cooperation 

 with the American Society of Testing Materials and the Bureau of 

 Standards have progressed well. It is believed that the actual ex- 

 posure will be started on the Arlington farm early in the coming 

 fiscal year. 



Work has been continued on platinum laboratory utensils and on 

 enamel-ware cooking utensils. The methods of testing inks and 

 typewriter ribbons have been given much study and. it is believed, 

 have been considerably improved. 



Publications from this laboratory during the year have covered 

 the subjects of the refractive index of beeswax (Bureau of Chem- 

 istry Circular 86), the fluorescent test for mineral and rosin oils 

 (Circular 84), the calcium-carbid method for determining moisture 

 (Circular 97), and the use of paint on the farm (Farmers' Bulletin 

 474). 



Two thousand four hundred and forty-two samples have been 

 examined for the various Government departments. The attached 

 table shows the distribution of the work according to the material 

 examined and the departments for which the examinations were 

 made. In addition to the samples reported in the table, over 1,800 

 pieces of apparatus were examined for the Bureau of Chemistry. 



Number and distribution of samples of contract supplies analyzed in 1912. 



' Including Bureau of Engraving and Printing. 



* Including Bureau of Chemistry. 



• Including National Museum and National Zoological Park. 



INVESTIGATIONS OF THE LEATHER AND PAPER LABORATORY. 



Leather. 



The work on sole leather mentioned in the last year's report has 

 been extended to embrace a number of other samples of more recent 

 production, and the results have been prepared for publication. Much 

 work has been done on bookbinding, carriage, automobile, and furni- 

 ture leathers, showing that (lie same harmful practices which are 

 prevalent in the tanning of sole and other heavy leathers exist among 



