BUREAU OF CHEMISTRY. 359. 



Much work was done in perfecting the type samples for naval 

 stores. Like rosin, turpentine is graded on the primary markets on 

 its color, and preliminary standards for the various grades of tur- 

 pentine have been prepared. Several sets of these standards are now 

 in the hands of the trade for trial and comment. In order to make 

 sure that the standard rosin types, which are now, under the naval 

 stores act, the United States rosin standards, are kept in perfect con- 

 dition, all sets have been recalled from the depositories, thoroughly 

 overhauled, calibrated, and redeposited. This work must be done 

 every year. 



Demonstrations were made of improved processes for preparing 

 rosin and turpentine. The bulk of the naval stores produced in this 

 country is made at smaller places, owned in many instances by 

 farmers in the Southern States. The naval stores industry is thus 

 largely a plantation industry, where the possibilities for financial 

 loss through wasteful methods of operation, insufficient and incor- 

 rectly designed equipment, poor location of i3lant, and faulty han- 

 dling of the finished products are numerous. Most of the dem- 

 onstration work is done in the field by an experienced naval stores 

 man, who visits the naval stores places and demonstrates better 

 methods of production and the elimination of wastes as adapted 

 specialh^ to the still under consideration. 



COLOR, MEDICINAL, AND TECHNICAL INVESTIGATIONS. 



The Bureau of Chemistry maintains a laboratory and a small ex- 

 perimental factory at the Arlington Experimental Farm to do the 

 work authorized in the appropriation act as follows, " For investiga- 

 tions and experiments in the utilization, for coloring, medicinal, 

 and technical purposes, of raw materials grown or produced in the 

 United States." 



INVESTIGATION OF COLOR SUBSTANCES. 



The investigation of color substances is directed along lines which 

 will help the manufacturer of dyes and intermediates to acquire 

 better control of factory processes and to improve the quality of 

 the products. This is accomplished by undertaking exhaustive 

 studies on the physical and chemical properties of the crudes, inter- 

 mediates, and dyes, and on those basic reactions which have a bear- 

 ing on the whole industry. Special emphasis is placed on the 

 development of new or improved methods of analysis for the de- 

 tection and determination of the intermediates. The laboratory is 

 well equipped with apparatus for production and tests on a semi- 

 manufacturing scale, with which uniform batches of the substances 

 studied may be obtained, and with which new processes may be 

 studied on a larger scale than is possible in an ordinary laboratory. 

 Cooperation not only with manufacturers but also with users of 

 dyestuffs is encouraged to the fullest extent. Upon occasion the 

 laboratory will produce special dyes which are needed for impor- 

 tant work and which are not obtainable elsewhere, until a manu- 

 facturer can be interested in their production. The function of 

 this laboratory is to aid in a stimulative, noncompetitive way the 

 development of the American dye industry. 



During the year the work included the standardization of bio- 

 logical stains used to identify disease organisms. The chemical 

 78007— AGR 1923 24 



