BUREAU OF CHEMISTRY, ' 279 



An idea of the scope of the color work of the bureau can, perhaps, 

 be gained best by examininof the list of its researches published or 

 prepared for publication during the 3'ear. A few of these papers are 

 mentioned elsewhere in this report. The others are: The Melting 

 Point of Pure Phthalic Anhydride. The System : Phthalic Anhy- 

 dride — Phthalic Acid; The System: Naphthalene — Phthalic Anhy- 

 dride; The Vapor Pressui-e of Phthalic Anhydride; The Fusion of 

 Sodium />-Cymene sulfonate with Sodium Hydroxide for the Pro- 

 duction of Carvacrol; The Fusion of Sodium Benzene m-Disul- 

 phonate Avith Sodium Hydroxide for the Production of Resorcinol; 

 A Synthesis of Thymol from yj-Cymene; The Preparation of 2- 

 Chloro-5, 6-Dinitrocymene ; Purification of Benzoic Acid by Frac- 

 tional Condensation; The Crystallograph)^ and Optical Properties 

 of the Photographic Sensitizing Dye, Pinaverdol; The Absorption 

 Spectra of the Nitric Esters of Glycerol; Some Aspects of the Be- 

 havior of Charcoal with Respect to Chlorine; The Production of 

 Hydrochloric Acid from Chlorine and Water; The use of Catalysts 

 in Sulfonation of Aromatic Compounds; Synthesis of s-Xylidine. 



LEATHER AND TANNING. 



Publications entitled Notes on the Determination of Water Solu- 

 bles in Leather, and Kaolin for Tannin Analysis have been issued. 

 Reports have been made before technical societies upon waterproof- 

 ing leather, upon a method for testing materials for increasing the 

 water resistance of sole leather, and upon the relative absorption of 

 oils and greases hj wet and dry leather. Articles on the effect of 

 humidity on the strength and stretch of leather, on the value of 

 pahnetto and willow bark as sources of tannin and Farmers' Bulle- 

 tin 1188, The Care of Leather, have been prepared for publication. 



Eighteen hundred pairs of Army shoes have been made up from 

 specially selected leather and material. The shoes have been put in 

 service at Camp Funston, Fort Bliss, and Columbus, N. Mex., and 

 have been constantly under the inspection of a member of the leather 

 and paper laboratory. Most of these service tests are nearing com- 

 pletion. A portion of the leather has been cut up into taps for half- 

 soling. Taps have been numbered and paired off according to con- 

 trasting features. Arrangements have been made to repair shoes of 

 policemen, letter-carriers, and civilians with these taps. The records 

 of the Avear of these tapped shoes are being kept under the super- 

 vision of the laboratory. In this way it is hoped to obtain data sup- 

 plementing the results from the Army tests. In cooperation with the 

 American Leather Chemists' Association much work was done on the 

 following subjects: The determination of water solubles in leather, 

 the sampling and preparation of leather for analysis, moisture in 

 leather, Epsom salts in leather, the determination of oils and greases 

 in leather. 



Among other results it was learned that relative humidity mate- 

 rially affects the tensile strength of leather so that a study is now 

 being made to determine the necessity of testing under controlled 

 conditions of temperature and humidity. This point is of impor- 

 tance since it has been ignored in all work on the strength of leather 

 published in this country, and so far as known has been considered 



