NATURE 



169 



THURSDAY, DECEMBER 21 



t899- 



THE COMING WHEAT SCARCITY. 

 The Wheat Problem. Based on remarks made in the 

 Presidential Address to the British Association at 

 Bristol in 1898. Revised, with an answer to various 

 critics. By Sir William Crookes, F.R.S. (London : 

 John Murray, 1899.) 



THIS essay by Sir William Crookes, as will be 

 remembered, called forth much criticism when it 

 was delivered as the Presidential Address at the Bristol 

 meeting of the British Association. Now that it is re- 

 printed with additions, it may demand a more careful 

 review than was possible at the time. The general idea, 

 it may be said, is by no means novel, and it is one which 

 approved itself to commo n sense. The population 

 of the world and of different races in the world in- 

 creases at rates which are more or less ascertainable. 

 The means of supplying its wants, either in the shape 

 of coal, or metals, or food, is also limited, either by 

 the amount of the accumulated stocks, or the means of 

 working them, or the extent of the earth's surface avail- 

 able for producing the food. What more natural then 

 than to calculate, as has been done by Malthus, as to food 

 generally, by other statisticians as to food in particular 

 districts, such as India at the present time, by Jevons as to 

 coal in England, by Prof. Cairnes as to metals generally, 

 and by Prof. Suess, an Austrian geologist and statistician, 

 as to gold specially, that at a given date in future the 

 supply must run short, and then a crisis arrive ? Sir 

 William Crookes applies specially to the study of wheat 

 production this leading idea. The consumers of wheat, 

 he tells us, are a little over 500 millions at the present 

 time, having increased to that figure from about 370 

 millions in 1870, while the quantity of the earth's surface 

 available for wheat is itself limited both by the capacity 

 of the soil and the necessity for cultivating other pro- 

 ducts. He calculates accordingly that by the year 193 1, 

 if population increases as it has done, the supply of wheat 

 will be seriously short, and he suggests that chemistry 

 should come to the rescue by devising means to fix the 

 nitrogen of the atmosphere so as to permit the growth of 

 more wheat on the same soil. 



In all this argument, except as to the last suggestion. 

 Sir William Crookes is plainly on the common ground 

 of men of science and philosophers. He may be right 

 or wrong as to details, such, for instance, as fixing 193 1 

 for the time when the "shortage" of wheat will be felt ; 

 but given the initial hypotheses, there must be in time a 

 deficiency of the supply to meet the demand for wheat— 

 as well as for other food articles, it may be added— if 

 present conditions of growth of population, and growth 

 of wealth per head in that population, continue. 



But at this point I fear the main commendation of Sir 

 William Crookes' essay must stop. His attempt to give 

 precision to the prospect as regards wheat (and the 

 whole gist of his paper is to emphasise the precision of 

 the forecast) appears to me rather to fail, while he does 

 not handle statistical data in the skilled, scientific 

 manner we should expect from a man of his eminence 

 NO. 1573, VOL. 61] 



even in a field which he does not usually cultivate. 

 Above all, instead of confii^ing himself to the forecast 

 that a certain position will be arrived at at a future date, 

 if present conditions continue, the conclusion to which 

 expert statisticians now confine themselves, he assumes 

 the continuance of the conditions, and argues for practical 

 measures to meet the apprehended difficulty. In other 

 words, although the general idea of the essay is sound, 

 the execution appears to be somewhat wanting, and the 

 result is not altogether what we should expect from a 

 man of science so distinguished as Sir William Crookes. 

 To take first the last point mentioned, the failure to 

 recognise the necessary limitation of all such specu- 

 lations in consequence of the assumption that must be 

 made that present conditions continue unaltered. I hold 

 this to be a capital error on the part of Sir William 

 Crookes. There has been much experience of these 

 discussions since the time of Malthus, and the whole 

 effect of the experience is that, as yet, we are either too 

 far away from the limits when shortness of supply of 

 food and raw materials, which men of science and philo- 

 sophers anticipate, will be felt, to engage in a precise 

 discussion, or that we know too little as to the ultimate 

 causes of existing conditions to be able to predict 

 whether they will be soon changed or not. The fore- 

 casts of Malthus regarding England and the older 

 countries of Europe that the supply of food would run 

 short have not yet come true, because an outlet in the 

 shape of emigration to new countries has been provided, 

 with the double effect that the multitudes who were 

 expected by Malthus to live in the old countries and 

 press on the narrow supplies there are now largely 

 settled in new countries, and are not only growing food 

 for themselves, but for some of the multitudes remaining 

 in the old countries as well, this last condition being 

 rendered possible by the entirely new developments of 

 means of communication which have taken place since 

 Malthus wrote. Since Malthus wrote, also, there has 

 been a general and vast improvement in the art of 

 cultivating the soil. Similarly, as regards coal, the 

 growth of the demand has by no means continued at 

 the rate which Jevons found in existence when he wrote, 

 while the influence of the price of coal as a factor in 

 production has diminished in consequence of the greater 

 effectiveness of the machinery which coal is used to 

 drive. The scarcity of the supply of gold, which the 

 Austrian geologist anticipated, seems also to be deferred 

 indefinitely by the discoveries in the Transvaal, Western 

 Australia, and the Klondyke ; while as to the demand 

 for gold, it is equally plain that nothing is more uncertain 

 than the continuance of the present condition of an over- 

 whelming desire by military governments to secure and 

 lock up enormous sums of gold. Experience is thus 

 altogether against making precise forecasts on the lines 

 laid down by Malthus. Consequently, when a new 

 authority takes up a similar subject, we should expect 

 him to be wide-awake to such considerations, as have 

 been found so important in like cases. The conclusions 

 should always be stated with an " if" — a big "if" — and 

 there should be no attempt at precision in the forecasts, 

 against which there are so many 'chances that they will 

 not, in fact, be realised. The man of science should be 



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