September 8, 1898] 



NATURE 



443 



bushels per acre — an increase of 24 '5 bushels. In other words, 

 22 "86 lbs. of nitrate of soda produce an increase of one bushel 

 of wheat. 



At this rate, to increase the world's crop of wheat by 7*3 

 bushels, about i^ cwt. of nitrate of soda must annually be 

 applied to each acre. The amount required to raise the 

 world's crop on 163,000,000 acres from the present supply of 

 2,070,000.000 bushels to the required 3,260,000,000 bushels 

 will be 12 million tons distributed in varying amounts over the 

 wheat-growing countries of the world. The countries which 

 produce more than the average of 127 bushels will require less, 

 and those below the average will require more ; but, broadly 

 speaking, about 12,000,000 tons annually of nitrate of soda will 

 be required, in addition to the 1} million tons already absorbed 

 by the world. 



It is difficult to get trustworthy estimates of the amount of 

 nitrate surviving in the nitre beds. Common rumour declares 

 the supply to be inexhaustible, but cautious local authorities 

 state that at the present rate of export, of over one million tons 

 per annum, the raw material *' caliche," containing from 25 to 

 50 per cent, nitrate, will be exhausted in from twenty to thirty 

 years. 



Dr. Newton, who has spent years on the nitrate fields, tells 

 me there is a lower class material, containing a small proportion 

 of nitrate, which cannot at present be used, but which may 

 ultimately be manufactured at a profit. Apart from a few of 

 the more scientific manufacturers, no one is sanguine enough to 

 think this debatable material will ever be worth working. If 

 we assume a liberal estimate for nitrate obtained from the lower 

 grade deposit, and say that it will equal in quantity that from 

 the richer quality, the supply may last, possibly, fifty years, at 

 the rate of a million tons a year ; but at the rate required to 

 augment the world's supply of wheat to the point demanded 

 thirty years hence, it will not last more than four years. 



I have passed in review all the wheat-growing countries of the 

 world, with the exception of those whose united supplies are so 

 small as to make little appreciable difference to the argument. 

 The situation may be summed up briefly thus : — The world's 

 demand for wheat — the leading bread-stuft" — increases in a 

 crescendo ratio year by year. Gradually all the wheat-bearing 

 land on the globe is appropriated to wheat-growing, until we 

 are within measurable distance of using the last available acre. 

 We must then rely on nitrogenous manures to increase the 

 fertility of the land under wheat, so as to raise the yield from 

 the world's low average — 127 bushels per acre— to a higher 

 average. To do this efficiently and feed the bread-eaters for a 

 few years will exhaust all the available store of nitrate of soda. 

 Yox years past we have been spending fixed nitrogen at a 

 culpably extravagant rate, heedless of the fact that it is fixed with 

 extreme slowness and difficulty, while its liberation in the free 

 state takes place always with rapidity and sometimes with 

 explosive violence. 



Some years ago Mr. Stanley Jevons uttered a note of warning 

 as to the near exhaustion of our British coalfields. But the 

 exhaustion of the world's stock of fixed nitrogen is a matter of 

 far greater importance. It means not only a catastrophe little 

 short of starvation for the wheat-eaters, but indirectly, scarcity 

 for those who exist on inferior grains, together with a lower 

 standard of living for meat-eaters, scarcity of mutton and beef, 

 and even the extinction of gunpowder ! 



There is a gleam of light amid this darkness of despondency. 

 In its free state nitrogen is one of the most abundant and 

 pervading bodies on the face of the earth. Every square yard 

 of the earth's surface has nitrogen gas pressing down on it to 

 the extent of about seven tons — but this is in \\\^ free state, and 

 wheat demands it fixed. To convey this idea in an object- 

 lesson, I may tell you that, previous to its destruction by fire, 

 Colston Hall, measuring 146 feet by 80 feet by 70 feet, con- 

 tained 27 tons weight of nitrogen in its atmosphere ; it also 

 contained one-third of a ton of argon. In the free gaseous 

 state this nitrogen is worthless ; combined in the form of nitrate 

 of soda it would be worth about 2000/. 



For years past attempts have been made to effect the fixation 

 of atmospheric nitrogen, and some of the processes have met 

 with sufficient partial success to warrant experimentalists in 

 pushing their trials still further ; but I think I am right in 

 saying that no process has yet been brought to the notice of 

 scientific or commercial men which can be considered successful 

 either as regards cost or yield of product. It is possible, by 

 several methods, to fix a certain amount of atmospheric nitrogen ; 



NO. 1506, VOL. 58] 



but to the best of my knowledge no process has hitherto con- 

 verted more than a small amount, and this at a cost largely in 

 excess of the present market value of fixed nitrogen. 



The fixation of atmospheric nitrogen therefore is one of the 

 great discoveries awaiting the ingenuity of chemists. It is cer- 

 tainly deeply important in its practical bearings on the future 

 welfare and happiness of the civilised races of mankind. This 

 unfulfilled problem, which so far has eluded the strenuous 

 attempts of those who have tried to wrest the secret from nature,, 

 differs materially from other chemical discoveries which are in 

 the air, so to speak, but are not yet matured. The fixation of 

 nitrogen is vital to the progress of civilised humanity. Other 

 discoveries minister to our increased intellectual comfort, 

 luxury, or convenience ; they serve to make life easier, to hasten 

 the acquisition of wealth, or to save time, health, or worry. 

 The fixation of nitrogen is a question of the not far distant 

 future. Unless we can class it among certainties to come the 

 great Caucasian race will cease to be foremost in the world, and 

 will be squeezed out of existence by races to whom wheaten 

 bread is not the staff" of life. 



Let me see if it is not possible even now to solve the 

 momentous problem. As far back as 1892 I exhibited, at one 

 of the soirees of the Royal Society, an experiment on " The 

 Flame of Burning Nitrogen." I showed that nitrogen is a 

 combustible gas, and the reason why when once ignited the 

 flame does not spread through the atmosphere and deluge the 

 world in a sea of nitric acid is that its igniting point is higher 

 than the temperature of its flame — not, therefore, hot enough to 

 set fire to the adjacent mixture. But by passing a strong, 

 induction current between terminals the air takes fire and con- 

 tinues to burn with a powerful flame, producing nitrous and 

 nitric acids. This inconsiderable experiment may not unlikely 

 lead to the development of a mighty industry destined to solve 

 the great food problem. With the object of burning out nitrogen 

 from air so as to leave argon behind, Lord Rayleigh fitted up 

 apparatus for performing the operation on a larger scale, and 

 succeeded in effecting the union of 29*4 grammes of mixed 

 nitrogen and oxygen at an expenditure of one horse-power. 

 Following these figures it would require one Board of Trade 

 unit to lorm 74 grammes of nitrate of soda, and therefore 

 14,000 units to form one ton. To generate electricity in the 

 ordinary way with steam engines and dynamos, it is now 

 possible with a steady load night and day, and engines working, 

 at maximum efficiency, to produce current at a cost of one-third ot 

 a penny per Board of Trade unit. At this rate one ton of nitrate 

 of soda would cost 26/. But electricity from coal and steam 

 engines is too costly for large industrial purposes ; at Niagara, 

 where water power is used, electricity can be sold at a profit for 

 one-seventeenth of a penny per Board of Trade unit. At this 

 rate nitrate of soda would cost not more than 5/. per ton. Bui 

 the limit of cost is not yet reached, and it must be remembered 

 that the initial data are derived from small scale experiments, in 

 which the object was not economy, but rather to demonstrate 

 the practicability of the combustion method, and to utilise it for 

 isolating argon. Even now electric nitrate at 5/. a ton com- 

 pares favourably with Chili nitrate at 7/. \os. a ton ; and all 

 experience shows that when the road has been pointed out by a 

 small laboratory experiment, the industrial operations that may 

 follow are always conducted at a cost considerably lower than, 

 could be anticipated from the laboratory figures. 



Before we decide that electric nitrate is a commercial possi- 

 bility, a final question must be mooted. We are dealing with 

 wholesale figures, and must take care that we are not simply 

 shifting difficulties a little further back without really diminish- 

 ing them. We start with a shortage of wheat, and the natural 

 remedy is to put more land under cultivation. As the land can- 

 not be stretched, and there is so much of it and no more, the 

 object is to render the available area more productive by a dress- 

 ing with nitrate of soda. But nitrate of soda is limited in 

 quantity, and will soon be exhausted. Human ingenuity can 

 contend even with these apparently hopeless difficulties. Nitrate 

 can be produced artificially by the combustion of the atmosphere. 

 Here we come to finality in one direction ; our stores are in- 

 exhaustible. But how about electricity? Can we generate 

 enough energy to produce 12,000,000 tons of nitrate of soda 

 annually? A preliminary calculation shows that there need be 

 no fear on that score ; Niagara alone is capable of supplying 

 the required electric energy without much lessening its mighty 

 flow. 



The future can take care of itself. The artificial production 



