SOILS FERTILIZERS. 517 



luauures do not lose potash in dry climates, no loss of this constituent heiug 

 observed in these experiments during the first 15 months. That this was not 

 due to insolubility of the potash in water was shown by experiments in which 

 air-dried sheep manure lost 43.7 per cent of potash, 22.6 per cent of phosphoric 

 acid, and 39 per cent of nitrogen when washed with water. In the series of 

 samples examined the potash, calculated on the basis of dry matter m the 

 manure, increased from an average of 4.4 per cent in fresh manure to 6.3 per 

 cent in one-year-old samples, remaining at this figure for several years. The 

 phosphoric acid remained at about 1 per cent of the dry matter irrespective 

 of the age of the manure. 



There was a large loss of nitrogen during the first 2 years, mainly as a 

 result of escape of free ammonia. Nitrogen as nitrates varied widely. Some 

 of the older manures carried large amounts of nitrates while others of the 

 same age contained almost none. The percentages of carbon and hydrogen in 

 the manures were practically constant and were apparently not affected by age. 



With the exception of insoluble ash, which increased with age, and free 

 ammonia and nitrogen, which decreased with age, there was remarkable uni- 

 formity in composition, indicating that under the conditions of these experi- 

 ments the manure was broken down by bacterial life at about the same rate 

 that leaching carried away the soluble salts. 



Recent investigations on the loss of nitrogen from manure, Vogel (Illus. 

 Landw. Ztg., 31 (1911), No. 40, pp. 3SD, 390).— The results of several recent in- 

 vestigations on this subject are briefly summarized. 



The theoretical basis for the use of commercial fertilizers, F. K. Cameron 

 (Jour. Indus, and Engin. Chem., 3 (1911), No. 3. pp. 188-191). — "In this paper 

 it is pointed out that: (1) Crop production is the result of many factors, 

 natural and artificial, and these factors are all mutually dependent. (2) No 

 simple theory of fertilizer action can satisfactorily account for the known 

 facts. (3) With intensive methods of cultivation, fertilizers are effective on all 

 kinds of soils, and are the more efficient on the naturally better soils. (4) 

 Other materials than those containing the traditional plant foods may yet 

 become valuable fertilizers, if they satisfy commercial requirements." 



Applied electrochemistry, M. deK. Thompson (New York, 1911, pp. XII + 

 329, figs. 137). — The portion of this book of special agricultural interest is the 

 chapter on fixation of atmospheric nitrogen, which describes the preparation 

 of calcium cyanamid, the oxidation of the nitrogen of the air, and the syn- 

 thesis of ammonia, the three general methods of fixing atmospheric nitrogen 

 now in operation. 



Recent progress in the fixation of atmospheric nitrogen, .J. B. C. Kershaw 

 (Elect. World, 57 (1911), No. 17, pp. 1035-1038, figs. 5).— It is stated that there 

 was considerable progress during 1910 in the industrial development of fur- 

 naces and processes for the fixation of atmospheric nitrogen, " It is estimated 

 that 100,000 horsepower is already applied to these processes of manufacture, 

 and that by the end of 1911 this total will be more than doubled." Several 

 of the newer manufacturing plants are described and the efliciency of the 

 different processes is discussed. 



The industrial fixation of atmospheric nitrogen, E. Lamt (Sog. Ingen. Civ. 

 France Bui., 1910, No. 7, pp. 61-86, figs. 6; abs. in Metallurg. and Chem. Engin., 

 9 (1911), No. 2, pp. 99-104, figs. 2; Ztschr. Elektrochem., 17 (1911), No. 11, p. 

 IfSJf). — The principal processes employed in the fixation of atmospheric nitrogen 

 are discussed, particularly the Pauling process as in operation at Notre-Dame 

 de Briangon, France. 



Hydro-electric plants in Norway and their application, A. Scott-Hansen 

 (Abs. in Mark Lane Express, 105 (1911), No. 4154, p. 635; Chem. Trade Jour., 



