134 The N.Z. Journal of Science and Technology. [Sept. 
product, and that none of these processes would be able to survive if they 
were dependent entirely upon the sale of nitrogen as a fertilizer. 
Chemical Methods of fixing Atmospheric Nitrogen. 
The principal chemical methods of fixing atmospheric nitrogen in use 
are the Haber, the Hauser, and the Serpek processes, in which the uses of 
electricity are ancillary only, such as heating a catalyser or for exploding 
a mixture of gases. These and other processes similar in character have 
received a great stimulus owing to the demand for explosives for carrying 
on the war, but it is not yet known whether they are working on a sound 
commercial basis. 
The best - known of these processes is the Haber process, by which 
hydrogen and nitrogen are made to combine under great pressure and high 
temperature in the presence of a catalyser, the gases being enclosed in a 
bomb and exploded by means of an electric spark. Germany is relying 
to a great extent on this process to make up for the deficiency caused by 
the interruption of the supply of Chile nitrate. They are now producing 
100,000 tons per annum of nitrogen by this process, compared with 115,000 
tons of nitrogen imported in the form of Chile nitrate prior to the war. 
They are also producing nitrogen by other artificial means which more 
than make up for the deficiency in Chile nitrate. It is not, of course, 
yet known whether this process can compete with Chile nitrate for fertilizer 
purposes. The situation, however, is a very favourable one for cheap 
production owing to the large quantities of by-product hydrogen and 
sulphuric acid available at the principal German chemical-works. 
Another process of fixing atmospheric nitrogen is the Hauser process, 
in which a mixture of coke-oven gas and air is exploded in a bomb by 
means of an electric spark, by which nitric acid is produced. This is also 
said to be carried on on a large scale in Germany since the war, but no 
particulars regarding the production are available. 
Another well-known process is that known as the Serpek process, by 
which atmospheric nitrogen is fixed by combination with aluminium in the 
form of a nitride. No particulars of production are available. Several 
variations of this method exist, but as far as is known at present there 
are none working on a commercial scale. 
None of these processes have been used to any great extent for the 
production of fertilizers, and they have been primarily introduced in 
order to manufacture nitric acid for explosives. It is quite possible, 
however, that improvements have been effected that will make them 
capable of producing nitrates at a price comparable with Chile nitrate, in 
which case there will be introduced further competitions with the calcium- 
carbide process for making cyanamide and the electric-arc process of 
making nitric acid for conversion into calcium nitrate. 
Natural versus Artificial Nitrogenous Products. 
As regards all artificial processes of fixing atmospheric nitrogen, whether 
using electricity or not, it appears that nitric acid and other products are 
more valuable and command a better price per unit of nitrogen than when 
converted into fertilizers, the reason being that the price of nitrogenous 
fertilizers is entirely regulated by the price of Chile saltpetre, or sodium 
nitrate. Any process of fixing atmospheric nitrogen has therefore to 
compete with the natural deposits, which for present purposes are inex¬ 
haustible, and capable of improvement and of reduction in price, whilst 
