8 June, ^907. 



New Sources of Available Nitrogen. 



331 



Lime Nitrogen or Calcium Cyanamide. — For the last seven or eight 

 years there has been manufactured by the Cyanid Gesellschaft, at Berlin, 

 a compound called " lime nitrogen " calcium cyanamide. It is prepared 

 by passing deoxidised air into an electric furnace filled with calcium 

 carbide. The carbide absorbs the nitrogen forming a fine black powder 

 ■ — calcium cyanamide — which contains from 19-20 per cent, of nitrogen, or 

 almost as much as sulphate of ammonia. 



Reviewing the experiments conducted by Dr. Haselhoff at jNlarburg, 

 Professor Wagner, Darmstadt, and A. D. Hall at Rothamsted, it would 

 seem that the manurial properties of lime nitrogen are of the highest 

 order, though in its present form its use can never become so cosmo- 

 politan as that of either nitrate of soda or sulphate of ammonia. 

 Tested side by side with the latter on barley and mangolds, Hall found that 

 the nitrogen in the cyanamide to be practically equal to that in the 

 ammonia salt, though the latter would appear to come more rapidlv into 

 use. The c\ anamide has first to be decomposed into ammonia and car- 

 bonate of lime. 



The actual figures obtained from the field experiments conducted in 

 England, Scotland and Germany are here given in tabulated form: — 



I. Barley test (N. D. Hall)— 



Manure. 

 Sulphate of Ammonia, 200 lbs. 

 " Lime Nitrogen/' 210 lbs. 



II. Rye test (Dr. Haselhoff) — 



Manure. 

 Unmanured 

 Nitrate of Soda 

 " Lime Nitrogen " 



III. Oat test (J. Hendrick) — 



Manure. 

 Unmanured 



Superphosphate, 2 cwt. . . . 

 Potassium Chloride, i cwt. 

 Nitrate of Soda, 142 lbs. 

 Superphosphate, 2 cwt. ... 

 Potassium Chloride, i cwt. 

 " Lime Nitrogen," i cwt. 



IV. IVIangold test (A. D. Hall)— 



The conclusions to be drawn from the Marburg experiments are that 

 the lime nitrogen interferes with the germination of the seed, but when 



