BUREAU OF CHEMISITRY. 465 



and tliis saving has been due largely to the adoption of suggestions 

 offered by this laboratory. 



TURPENTINE AND ROSIN. 



The results of the examination of 300 samples of commercial tur- 

 pentines, collected all over the country, have been published (Bulle- 

 tin 135). They show but little adulteration on the part of the pro- 

 ducer, while samples collected from dealers show from 13 to 18 per cent 

 of the samples to be adulterated with mineral oils present in amounts 

 varying from 2 to 3 per cent to 60 or 70 per cent. The average 

 amount of mineral oil in a barrel of adulterated turpentine was 3 

 gallons, equal to a depreciation in value of at least $1.50 per barrel. 



The results of the study of the production, refining, uses, and value 

 of wood turpentine have been compiled (Bulletin 144). The work 

 shows how the number, quality, and value of the products obtained 

 in the distillation of wood can be increased, how the quality of the 

 products may be improved, and the cost of production decreased, 

 rroperly refined wood turpentine has been found to be a suitable 

 paint and varnish thinner for all but the highest grade varnishes, and 

 it may be safely used by the workman in well-ventilated places. The 

 production of wood turpentine together mth other products of the 

 chemical treatment of waste wood, either by means of destructive 

 processes or by solvent processes, as previously outlined, is one of 

 the most promising chemical industries. 



The work on the grading of rosin has now reached the point where 

 the results can be presented. It shows that the misgrading of rosin 

 is largely due to the practice of cutting the grading samples too large, 

 as well as to the fact that the type samples rapidly bleach out, thus 

 becoming lighter in color than they should be. The quantity of rosin 

 which is misgraded from these causes is large, and the loss occasioned 

 thereby is always at the expense of the farmer who produces the rosin. 

 It is calculated on the basis of the work so far done that in the 

 neighborhood of 400,000 barrels of rosin are misgraded annually from 

 the above-mentioned causes alone. Work is being continued on the 

 preparation of more durable and serviceable rosin type samples, with 

 encouraging results. 



MISCELLANEOUS WORK. 



The work of testing deliveries of paper, textiles, leather, turpentine, 

 rosin, and other materials for the several Federal departments 

 requires much of the time of the laboratory force. Considerable 

 research is required in connection with this work, much useful 

 information has been acquired from it, and several improvements in 

 testing appaiatus have been devised. Specifications to insure the 

 delivery of materials suitable for specific purposes have been pre- 

 pared at the request of other departments. 



Miscellaneous samples, including fertiliz&rs, phosphates, wastes, 

 and various industrial materials have bean examined at the request of 

 other departments and of other bureaus of this department and the 

 laboratory has cooperated in the study of methods for the examina- 

 tion of leather and tanning materials. An extended study of the 

 fluorin in phosphate powders and of iron and alumina in phosphates 

 is in progress. 



231G5°— AGE 1911 30 



