REPORT OF THE COMMISSIONER OP AGRICULTURE. 11 



To the juice as it comes from the mill, or the diffusion battery, a large 

 excess of lime is added, aud this is afterwards precipitated by blowiujr 

 tbrough the mixture a current of carbonic acid. The precipitate which 

 falls, carries down with it nearly all the impurities of the juice aud 

 leaves them in a state suitable to easy separation by filtration. The 

 use of this i^rocess entirely prevents the losses from scums, and aflbrds 

 a product in every way superior to that given by the old method. 



It was the intention of the Department to make similar experiments 

 in Louisiana, and preparations for them are nearly finished. But delay 

 in getting a part of the apparatus and the improvements suggested by 

 the experiments in Kansas, rendered it advisable to postpone the work 

 for another year. 



In view of the important results achieved by the experiments in 

 Kansas under the direction of the chemist of this Department, I have 

 thought it advisable to seed him to Europe for the purpose, not only 

 of more thoroughly familiarizing himself with the processes of diffusion 

 aud carbonatation, but also to examine machinery recently designed 

 for cutting up cane, with a view to purchasing such apparatus as is 

 necessary to carry the proposed experiments of another year to a suc- 

 cessful termination. 



FOOD ADULTEIIATION. 



It is highly desirable that some general standard of purity for foods 

 should bo established and that uniform methods of examination for 

 adulterations be agreed upon. As a beginning in this direction the 

 Division of Chemistry has begun a series of investigations in food adul- 

 teration. The work already done has been chiefly with butter and honey, 

 and the general results of the analyses tend to establish an average 

 composition for each of these articlesof food, which, when more definitely 

 described, may serve as a standard of comparison. The work has fur- 

 ther shown the character and extent of the adulterations. 



The work with honey will soon be concluded, but with butter and 

 other dairy products only a beginning has been made. It is proposed 

 to extend this line of investigation until the ends sought for are at- 

 tained. 



MISCELLANEOUS. 



In this categorj' is to be placed a large amount of work done by the 

 division which is so varied as to escape a more particular classification. 



It includes many analyses of waters, assays of minerals, examination 

 of marls, phosphatic rocks, and artificial fertilizers, «S:c. 



Perhaps the most important work of a miscellaneous nature was that 

 done in connection with the Association of Official Agricultural Chem- 

 ists, whose labors have led to the adoption of uniform methods of 

 analysis for commercial fertilizers throughout the United States. 



By invitation of the Depa-rtment the last meeting of the association 

 was held in Washington, and action was taken relating to the enlarge- 



