326 EXPERIMENT STATION RECORD. [Vol.38 



iiure alone. The manure had no effect upon the assimilation of phosphoric acid 

 from rock phosphate in these experiments. " 



Acid phosphate v. raw phosphate rock, C. E. Thorne (Mo. Bui. Ohio St a., 

 2 {1911), No. 11, pp. S50-S56, figs. S).- Reviewing the results of fertilizer ex- 

 periments at Strongsville (E. S. R., 36, p. 820) during the past 13 years, in a 

 comparison of the effects of raw rock phosphate and acid phosphate used alone 

 and in combination with lime and other fertilizing materials upon the wheat 

 crop in a rotation of corn, oats, wheat, clover, and timothy, it was found that 

 the 5,000 lbs. of rock phosphate used during the 13 years returned more than 

 three times its cost in increased yields, and that the 960 lbs. of acid phosphate 

 used returned more than ten times its cost. It was concluded, therefore, that 

 " it is not a question whether rock phosphate may be used with profit, but 

 merely one of relative profit. " 



Heactions of the phosphorus of the thickened root of the flat turnip, B. L. 

 PIaktwell, F. S. Hammett, and P. H. Wessels {U. S. Dept. Agr., Jour. Agr. 

 Research, 11 {1911), No. 8, pp. 359-310) .—Previous investigations at the Rhode 

 Island Experiment Station (E. S. R., 29, p. 417) have shown that the percent- 

 age of total phosphorus in flat turnip roots {Brassica rapa) grown in different 

 soils generally varied in the same direction as variations in the amount of phos- 

 phorus available to the plant. Further investigations were undertaken to ascer- 

 tain whether the amount of any portion of the phosphorus of the turnip root 

 might be more nearly correlated than total phosphorus with the relative amount 

 available in soils. 



Preliminary studies indicated that larger amounts of phosphorus could be 

 extracted from fresh than from dried material. Microchemical examinations 

 of turnip roots grown in culture solutions with and without phosphorus and 

 chemical examinations of turnip extracts are discussed, together with results 

 of dialysis of the extracts. The results are summarized as follows : " Coinci- 

 dent with the introduction of phosphorus into a nutrient solution in which tur- 

 nips were growing, the appearance of ' inorganic ' phosphorus and the disappear- 

 ance of starch were traced microscopically in the different tissues ; whereas 

 upon withholding phosphorus the disappearance of inorganic phosphorus and the 

 appearance of starch were similarly observed. About four-fifths of the total 

 phosphorus of fresh turnips was extracted with water. When the latter was 

 acidulated, somewhat less was secured because of partial precipitation. 



" Only a few per cent of the extracted phosphorus failed to pass through 

 dialyzers. Different precipitant^ of inorganic phosphorus were tested as to 

 their ability to recover phosphate added in a standard solution to the dialyzates. 

 The phosphorus in the precipitate formed by adding acetic acid to turnip juice 

 was not in phosphoprotein compounds. There was no phytin in the juice. The 

 presence of a phosphatase was not shown. 



" Although the proportion of inorganic to total phosphorus in turnips was 

 frequently made larger by phosphatic applications to the soil in which they were 

 grown, this was not always shown to be the case by such methods as were used. 

 In most instances the phosphorus in the juice was so largely inorganic and con- 

 stituted so large a proportion of the total that the determination of the latter 

 seemed about as useful as of any portion for furnishing indications regarding 

 the relative amount of soil phosphorus at the disposal of the turnip. " 



A list of references to literature on the subject is given. 



Potash in 1916, H. S. Gale (V. S. Geol. Survey, Min. Resources U. S., 1916, 

 pt. 2, pp. V+13-111, figs. 2). — This report, dealing with the production of 

 potash in 1916 and developments and projects therefor in the United States, 

 states that "the manufacturers of potash salts and potash products in the United 



