242 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



cement plants have been collected and analyzed, and the bureau seeg 

 in this field the opportunity to produce much of the potash needed 

 in the agriculture of the country. Work is being done on the avail- 

 ability of the potash found in blast furnace and cement-plant fluo 

 dust. ^ 



During the fiscal year ended June 30, 1918, the kelp plant at Sum- 

 morland, Calif., in charge of Dr. J. W. Turrentine, was in partial 

 o[;eration. The close of that year found this organization ap- 

 proaching the end of its first year of operation. It was struggling 

 with many problems and difficulties, some of inherent origin and 

 some resulting from the national condition of a state of war. In 

 spite of these, however, the experiments and the investigations were 

 behig actively prosecuted with a view to the determination of by- 

 products, the elaboration of processes for their recovery, the perfect- 

 ing of processes already installed, and the establishment of complete 

 cost and efficiency data regarding all features. These problems were 

 under full development. Organization and production had been 

 brought to a point where over considerable periods operating ex- 

 penses were approximately equaled by proceeds from sale of the 

 products dry kelp and kelp ash. 



At the beginning of the new year, the problem demanding most 

 inuuediate solution was that of the large-scale leaching of kelp char. 

 This had to be done mechanically and by a nonintermittent process. 

 Processes devised by other concerns were either entire failures or 

 cumbrous and highly inefficient. Following plans drawn up in 

 this office and data established by experimentation here, a lixiviator 

 was constructed and installed and put into operation which repre- 

 sented the immediate and complete solution of this problem. 



Following this, the evaporator equipment, already tested by inter- 

 mittent operation, was put into steady use, and high-grade potasli 

 salts became a daily product. Centrifugal and rotary, counter- 

 current, hot-air dryers were installed to reduce the potash salts to the 

 desired moisture content, and a material of high potash content and 

 of a satisfactory physical condition was thus established as a daily 

 product. 



As in every other operation, a considerable period of time was con- 

 sumed in training our operating crew in the details of producing 

 potash salts and in studying the best method of operation of the 

 apparatus installed. Although the evaporator and crystallizer have 

 been in successful operation for half a year, the refinements of opera- 

 tion yielding potassium chloride of the highest degree of purity have 

 not yet been introduced. This being a matter of no immediate ur- 

 gency, it has been permitted to await a more favorable opportunity. 



As a part of the problem of determining the various factors that 

 influence iodine with respect to its concentration and condition in the 

 various stages of its course from the wet, raw kelp to the mother 

 liquor from which iodine is precipitated, Prof. Merle Randall, of the 

 Department of Chemistry of the University of California, is making 

 a complete study of the composition of solutions; and, on the basis 

 of the results to be obtained, it should be possible easily to introduce 

 those modifications in process which will result in a grade of product 

 so high as to commend itself to the chemical trade and demand a cor- 



