January 24, 19 18] 



NATURE 



407 



are obtained when the phosphates are treated with 

 sulphuric acid. But this requires pyrites from 

 Spain, which is no longer easy to get, and in 

 any case the resulting sulphuric acid is also 

 needed for making explosives. Other sources 

 of sulphur are, therefore, being exploited, in par- 

 ticular the pyrites and the pyrrhotic deposits of the 

 Eastern States and the sulphur deposits of Louisi- 

 ana and Texas. 



The nitrogen problem is extremely urgent. 

 Chilean nitrates are largely used for making ex- 

 plosives, and are practically unobtainable for 

 agricultural purposes. Prior to the war the 

 largest source of fertiliser nitrogen in the 

 United States had been the various organic 

 products, such as tankage, fish scrap, and cotton- 

 seed meal, produced in the country. With the 

 coming of the war, however, other demands have 

 been put upon most of these, and their prices have 

 risen ; thus cotton-seed meal is now used as animal 

 food. 



Coal is a satisfactory source of nitrogen, one 

 ton of American coal containing on an average 

 20 lb. of nitrogen. The proportion actually re- 

 covered,, however, is only small, correspo"nding in 

 191 3 with 3 per cent, of the total quantity of coal 

 mined, but a higher recovery is said to be obtained 

 to-day. In 1913 about 12 per cent, of the coal (or 

 69,000,000 tons) was made into coke, but three- 

 quarters of this was done in the old bee-hive 

 oven, and only a quarter in the more modern 

 ovens from which recovery of the nitrogen is pos- 

 sible. This proportion, however, is steadily in- 

 creasing. 



All these methods are essentially transitory; 

 they come to an end in that indefinite time when 

 coal and nitrate of soda are both exhausted. The 

 permanent, never-failing supply is the atmosphere. 

 Already calcium nitrate, cyanamide, and ammonia 

 are produced synthetically, but of these only 

 cyanamide is as yet made in North America, and 

 that only on the Canadian side of Niagara. The 

 need, however, is fully recognised, and the work 

 is being vigorously pushed forward. The sum of 

 twenty million dollars was appropriated in 1916 

 for the construction of the plant, and although the 

 scheme is not yet in working order, we mav be 

 sure that it will materialise. The peculiar and 'pro- 

 found importance of these synthetic processes as 

 the central feature of the war is fully recognised, 

 and, as the author of the Bulletin justly remarks : 

 "It is significant that war was declared directly 

 after the successful development of the Haber and 

 cyanamide processes in Germany." 



The dependence of the civilised world on 

 Stassfurt for its necessary potash was accepted 

 as a natural and fundamental fact prior to the 

 war, and very little was done to obviate it. Potass- 

 ium is extremely common ; only seven other 

 ■elements are more abundant, and it is calculated 

 that there is more potash in the earth's crust than 

 water. But, unfortunately, workable deposits are 

 rare, and only the one at Stassfurt is actually 

 worked to any notable extent. For some time 

 before the war the United States Government 

 NO. 2517, VOL. 100] 



recognised the drawbacks of the position, and 

 caused a systematic search to be made for potash 

 within its own borders. A limited amount of 

 potash can be obtained from the wood-ashes of 

 the lumber industry in Michigan and Wiscon- 

 sin. Another source is the mineral alunite, a 

 potassium aluminium sulphate occurring in 

 moderate-sized deposits in Utah. Another, again, 

 is kelp produced from the giant seaweed of the 

 Pacific coast from Lower California to Alaska. 

 A more important source is the flue-dust obtained 

 from Portland cement works and from blast- 

 furnaces. Still more important from the point of 

 view of immediate production are the alkali lakes 

 of the West, which at present yield most of the 

 American supply : Jesse Lake, in western 

 Nebraska, supposed to derive its potash from the 

 i forests burnt on the adjacent plains ; Searles Lake, 

 in California, reputed to contain great quantities 

 j of potash, though there are so many other salts 

 ; as well that the extraction is by no means simple ; 

 Owen's Lake, also in California, several lakes in 

 I Oregon and elsewhere. In addition, there are salt 

 [ beds in Texas, Oklahoma, and other places where 

 j some of the underlying strata were formed in arid 

 I climates. 



There are still other possibilities which have 



! not yet come to anything, though they are not 



I without promise for the future : felspar, which 



I occurs in scattered and rather small deposits; 



I leucite, forming a conspicuous component in a 



rock mass of considerable size in Wyoming ; seri- 



cite, which forms extensive beds in Georgia ; and 



greensand, found widespread in the Atlantic 



coastal plain, especially in New Jersey. All these 



are open to exploitation. 



But what will be the future of these new fer- 

 tiliser industries, assuming they mature? Will 

 they disappear after the war, choked by the com- 

 petition of German products, or will they be kept 

 ahve by artificial support? This is a political 

 question scarcely less important than the chemical - 

 and engineering problems involved, and one which 

 we may be sure will receive serious and systematic 

 consideration. E. J. Russell. 



WHAT DETERMINES STATURE ?i 

 T\ R. C. B. DAVENPORT has collected data 

 '-^ in regard to human stature, and analysed 

 them by modern methods of studying heredity. 

 Some of the data refer to 2354 children of 

 parents whose height is recorded, but the pre- 

 cision of this recording was very unequal. The 

 other data refer to the inheritance of stature in 

 families, and these, while less numerous, are more 

 uniformly precise. 



For the class of people dealt with, it appears 

 that nutrition is not of much importance in deter- 

 mining stature. It is improbable that insufficient 

 or improper food counts for much in determining 

 eventual height; "temporary starvation has little 

 or no effect on the end result. So, likewise, 



1 Bulletin No. i8, " Inhrritance of Suture." Pp. 313-80+33 tables and 

 19 figs. (Eugenics Record Office, Cold Spring Harbour, N.Y., 1917.) Price 



