THE UTILISATION OF THE NITROGEN OF THE AIR. 183 
22. The Utilisation of the Nitrogen of the Air. 
By ALEXANDER LAUDER, D.Sc., Honorary Consulting Chemist to the 
Society. 
In a paper recently published in the TZyransactions of the 
Society (Vol. XIX. Part II. p. 245), Dr A. W. Borthwick gives a 
striking account of the progress which has been made in recent 
years in Germany, Belgium, and other continental countries in 
the application of artificial manures in forestry. The work 
described there can hardly be said to have passed much beyond 
the experimental stage, yet the results so far obtained certainly 
suggest that considerable use may be made in the future of 
artificial fertilisers in forestry. In this connection, therefore, I 
have thought that the recent attempts which have been made to 
utilise the nitrogen of the air for manurial purposes might be of 
sufficient general interest to justify a short description in the 
Transactions. 
It is now a matter of common knowledge that nitrogen is a 
constituent of all plants, and that unless an adequate supply of 
this element is available, the production of healthy vegetation is 
impossible. This element, nitrogen, exists in large quantities in 
the air, of which it forms about four-fifths of its bulk. 
Comparatively few plants, however, are able to utilise the 
nitrogen of the air directly, but can only make use of it when it 
is in combination with certain other elements, as we have it in 
nitrates, and, in consequence, the enormous stores of nitrogen 
existing in the atmosphere are of little use directly for fertilising 
purposes. For the supply of nitrogen to plants, then, we are 
limited to such suitable compounds of nitrogen as exist already 
formed in nature, or to such as we can prepare artificially. At 
present we have three main sources of supply, viz.—(1) 
farm-yard manure and other forms of organic nitrogen; (2) 
sulphate of ammonia; (3) nitrate of soda. Of these, only the 
sulphate of ammonia, obtained in the distillation of coal for 
gas or coke, may be said to be prepared artificially. When we 
consider the enormous annual waste of nitrogen in sewage, as 
well as the inevitable loss of nitrogen which takes place in the 
preparation of farm-yard manure, we see that we are gradually 
using up our stock of nitrogen compounds suitable for manuring, 
The nitrate deposits at Chili are by no means inexhaustible, 
and, together with this steady diminution in our supply of 
