BUREAU OF CHEMISTRY. 273 



standards undor which they were purchased. This work is carried 

 on not only in the various laboratories in \Vashino;ton but also in the 

 laboratories of the branch stations located in the leading trade centers 

 throughout the country. Other work included examination of a great 

 variety of samples for the different Government departments and 

 independent establishments. 



Assistance has been given to the congressional Joint Committee on 

 Printing in the preparation of paper specifications, and to the 

 Public Printer in establishing a testing section at the Government 

 Printing Office for testing paper and otlier supplies. About 50 

 samples of bookbinding leathers were examined for the Govern- 

 ment Printing Office to assist in checking deliveries against stand- 

 ard samples, drawing specifications, and making awards. Informa- 

 tion was supplied to the Navy Department on proposed specifications 

 for pneumatic and hydraulic leathers of high heat resistance. A 

 statement on the composition and adulteration of leather was pre- 

 pared for the Federal Trade Commission. 



COLOR INVESTIGATIONS. 



Investigations to aid in the development of a dye industry in the 

 Ignited States were continued. The practical results obtained in the 

 discovery of processes for the manufacture of certain dye inter- 

 mediates, which enable American manufacturers to make these in- 

 termediates in competition with German manufacturers who at one 

 time monopolized their manufacture, were previously reported. 



Indigo. — Indigo is one of the most important dyes manufactured 

 in the United States. The process at present in use in this country 

 has been not altogether satisfactory, and an investigation was under- 

 taken with a view of substituting an alternative method for the 

 preparation of this dye. A survey was made of the entire process 

 and the results obtained indicate that indigo of good quality can be 

 obtained at a somewhat lower price than is possible by the method 

 now in vogue. Two papers on this work were published. 



Indigo derivative from cymene. — A new dye similar in dyeing 

 properties to indigo has been made from cymene — a waste product 

 obtained in the preparation of paper pulp from certain resinous 

 wood. A paper giving a detailed description for making this ^yo. 

 was published. 



Anthraguinone from aiithracene. — Anthraquinone is an interme- 

 diate used in the preparation of the valuable dye " alizarin." A rela- 

 tively simple method was worked out for the making of anthra- 

 quinone from anthracene, one of the " crudes " obtained from coal tar, 

 using the oxygen of the air instead of the rather expensive chemicals 

 lieretofore used. A public-ser.vice patent was granted on this process. 



T'^7a/ 7xd. — Although this dye is used in only small amounts, it is 

 nevertheless of tremendous importance both in time of peace and in 

 war. It is used by physicians in testing blood volume. The medical 

 men have been unable to secure the dye in this country in satisfactory 

 quality and accordingl}' a complete study of the method of prepara- 

 tion was undertaken. Several batches have already been prepared 

 and submitted to expert medical investigators for examination. 

 Work on this dve is beinir continued. 



