﻿416 Notices respecting New Books. 



say that even if the war had not given an impetus to the change 

 over from the basic Bessemer and acid open-hearth processes, 

 economic considerations would none the less have demanded the 

 development of the basic open-hearth production of steel from 

 low-grade iron-ores. " This result" (to quote from the preface) 

 " is, of course, distinctly awkward for the agriculturist who sees a 

 valuable fertilizer disappearing, and being replaced by one which 

 is more costly and at first sight seems to be nothing like as 

 good." 



After a review of the various scattered experiments on the use 

 of rock phosphates and basic slags hitherto undertaken, Dr. Scott 

 Robertson describes in detail the Essex experiments carried out 

 in the winters of 1915, 1916, 1918, and 1919 under the auspices 

 of the East Anglian Institute of Agriculture. The soils treated 

 were those of the Chalk, London Clay, and Boulder Clay, and 

 varied considerably in mechanical and chemical composition. The 

 yields of hay and clover were correlated with the rainfall, and it 

 was found that the drier the season, the greater was the increase 

 in production due to the use of phosphates. The botanical 

 results are also given, the crowding-out of the weeds and the 

 covering of bare areas with grass being noteworthy. Dr. Robert- 

 son's main conclusion is that for root crops and late harvests with 

 high rainfall, rock phosphates will prove a suitable substitute for 

 the high-grade Bessemer basic slags. The careful records and 

 correlations were made personally by Dr. Robertson at consider- 

 able inconvenience and discomfort, and under most difficult 

 circumstances. They are therefore the more valuable, and do him 

 the greater credit. 



The latter part of the book is concerned with investigations of 

 the large yields resulting from the use of basic phosphates. From 

 botanical analyses it is evident that the open-hearth fluor-spar 

 slags of low solubility are less effective than the non-fluor-bearing 

 and therefore more highly soluble slags. The effects of the 

 temperature and texture of the soil on the accumulation of 

 nitrates, on the soil bacteria, and on the acidity and lime-require- 

 ment are clearly expounded, and the deductions emphasized by 

 means of abundant statistics. 



Altogether, the work constitutes a most valuable contribution 

 to agricultural knowledge. It is a pity that the publishers 

 cannot retail this book of 112 pages and 8 plates for less than 14s. 



P. G. H. B. 



