ON THP: NlTllOUEN INDUSTRY. 419 



Several new types of electrolytic cell have been worked out by inventors 

 in this country and in Switzerland, Italy, and America. Under present 

 conditions, with the high price of coke, hydrogen produced in bulk 

 from cheap hydro-electric power will compete easily with that obtained 

 by other methods. 



The cyanamide process, stated by many authorities to be obsolete 

 or, at any rate, obsolescent, had at the end of the War an aggregate 

 capacity in tons of nitrogen distinctly greater than that of any other 

 fixation method. It is true that since the Armistice many of the plants 

 have been closed. The largest of these, capable of producing about 

 200,000 tons annually, was erected during 1918 by the American 

 Government at Muscle Shoals, in Alabama. The American nitrogen 

 programme, including expenditure on unfinished plant, scrapped at the 

 time of the Armistice, cost no less than $140,000,000, Muscle Shoals 

 alone, exclusive of the hydro-electric scheme now being procee<led witli, 

 having cost nearly twice as much as Gretna. At present it is still 

 uncertain whether the Government will lease it to Henrv Ford or some 

 other private interest, or will keep it and the Sheffield pbnt in reserve. 



There has been no new development of outstanding importance in 

 the manufacture of cyanamide itself, although detailed improvements 

 have been n:iade ; but even under the present difficult conditions 

 cyanamide is still almost certainly the cheapest fonn of combined 

 nitrogen. In Germany, notwithstanding the recent big synthetic 

 ammonia development, plans are on foot to double the capacity of the 

 great cyanamide plants at Piesteritz. Cyanamide is an unsatisfactory 

 fertdiser for many soils. Examining an old sample of cyanamide, I found 

 that the nitrogen had practically changed over to dicyandiamide. Many 

 efforts have been made within the last few years to convert cyanamide 

 cheaply into some other nitrogen compound, but as yet with small 

 success. An American company is now manufacturing from cvanamide 

 a concentrated mixed fertiliser in the form of mono-ammonium phos- 

 phate, sold as " ammophos." This would appear to be a promising 

 material, but too costly for many applications. During the last year 

 independent investigators working in Sweden and Switzerland have 

 succeeded in perfecting processes whereby free cyanamide is prepared 

 by the action of carbonic acid on calcium cyanamide, and is subse- 

 quently converted into urea. In the Swiss process, excess of the 

 sulphuric acid employed in the second part of the transformation is 

 used to act on phosphate rock, which is changed to mono-calcium 

 phosphate, the final product being a neutral body known as phosphazote, 

 having its nitrogen content as urea and its phosphorus in the water- 

 soluble form, usually with 11-12 per cent, nitrogen and 11-12 per cent, 

 available P0O5. The cost of manufacture is said to be bv no means 

 high, and the substance has no deleterious action on the skin or on the 

 bags in which it is packed. It has been manufactured on a fair scale 

 for about six months, the product going mostly to France for vine 

 culture. These two processes, which are apparently in course of rapid 

 development, may prove to be a means, of rehabilitating cyanamide as 

 a product of fixation. 



1922 F F 



