NA TURE 



421 



THURSDAY, FEBRUARY 10, 1910. 



THE NUTRITION OF PLANTS. 

 Artificial Manures, their Chemical Selection and 

 Scientific Application to Agriculture. By M. 

 Georges Ville. Translated and edited by Sir 

 William Crookes, F.R.S. New edition, revised by 

 Sir William Crookes, F.R.S. , and Prof. John 

 Percival. Pp. xxxviii + 347. (London : Longmans, 

 Green and Co., 1909.) Price los. 6d. net. 



SIR WILLLA.M CROOKES and Prof. Percival have 

 revised and re-issued the lectures given by 

 Georges Ville at the experimental farm at Vincennes 

 during 1867 and 1874-5, ^"d originally translated by 

 Sir William in 1870. 



"It is only just;^ he says in introducing 

 the volume, " that its claims to be regarded 

 as a classic and its author's right to the title 

 of pioneer should not be forgotten when many of 

 Prof. Ville's views are so generally adopted that 

 his prescience and acumen are likely to be underrated 

 and his priority unrecognised." 



Ville was an ardent supporter of Liebig's views on 

 the nutrition of plants. He was one of the brilliant 

 band of men who at that time were developing and 

 spreading the new ideas ; several of the lectures deal 

 with his experiments showing that a full crop can be 

 obtained by supplying the proper food-stuffs in 

 inorganic combination. It is difficult for us now to 

 realise the astonishment with which the older farmers 

 saw crops raised solely by the aid of "chemical" 

 manures without the dung which had always been sup- 

 posed essential. Lawes and Gilbert showed that it 

 was not ; they also falsified the prediction of many of 

 their critics that chemical manures would soon exhaust 

 their land and leave it sterile. Ville went even further, 

 and maintained that artificial manures were un- 

 questionably more remunerative, and afforded, indeed, 

 the only means of keeping up the fertility of the soil. 

 A man who only used dung, he said, must exhaust his 

 land. This is the characteristic note of a great part 

 of the book. 



The chemical manures were compounded on a 

 definite plan. For each crop one of the three 

 constituents nitrogen, potash, and phosphoric acid 

 was found to be more necessary than the rest, and 

 was therefore called the dominant constituent. Thus 

 nitrogen was the dominant constituent for cereals and 

 beetroot ; potash for potatoes and vines ; calcic phos- 

 phate for the sugar-cane; there was no dominant, 

 however, for flax. An excess of the dominant 

 constituent was always added to the crop manure. 



Great stress was laid on the fundamental 

 differences in nitrogen nutrition between legu- 

 minous plants and cereals ; nitrogenous manures 

 are not necessary for the leguminosae, whilst 

 they are for other plants. M. Ville had played 

 a very prominent part in the great contro- 

 versy that continued during many years as to 

 the source of nitrogen in plants. It seems to have 

 been begun by Priestley, who stated that a plant of 

 Epilobium hirsntum, placed in a small vessel, absorbed 

 NO. 2102, VOL. 82] 



during the course of a month seven-eighths of the air 

 present. He therefore concluded that plants 

 assimilated nitrogen, but this view was soon con- 

 troverted by Ingenhousz, de Saussure, and others, and 

 was for a time disposed of by the classical experiments 

 of Boussingault. Ville, however, revived it, and his 

 experiments, begun in 1849 and described in two very 

 beautiful volumes, " Recherches experimentales sur la 

 Vegetation " (1853 and 1S57), appeared to show that 

 all the plants examined, rape, wheat, barley and maize, 

 actually did take some of their nitrogen from the air. 

 Somewhat later, Lawes, Gilbert and Pugh repeated 

 the experiments but failed to confirm the result. 

 They even used his experimental vessels, which are stilt 

 to be found among the treasures of the Rothamsted 

 laboratory. 



It is not our intention to discuss this discrepancy in 

 the light of subsequent discoveries ; we need only point 

 out that Ville was perfectly correct so far as the 

 leguminosae are concerned, and that his error with 

 regard to other plants did not lead him astray in 

 making up his manures. 



No value was placed upon soil analysis; 'at the 

 present time the most laborious analysis is not able 

 to throw light upon the most vital and essential 

 question of practical agriculture." The deficiencies of 

 the soil are determined by trials with the plants them- 

 selves. Plots are directed to be laid out in the field 

 as follows : — 



(i) With the normal (i.e. complete) manure; (2) 

 normal manure without nitrogen compounds; (3) 

 normal manure without phosphates ; (4) normal 

 manure without potassium compounds; (5) normal 

 manure without calcium compounds; (6) unmanured. 



This is substantially the- scheme now adopted in 

 almost every county in England. Under his super- 

 vision large numbers of such experiments were 

 carried out in France. Some of the results are 

 astonishing. In one case a plot receiving 32 tons of 

 farmyard manure per acre gave a crop of 14 bushels 

 per acre whilst a neighbouring plot receiving half a' 

 ton of chemical manure per acre yielded 36 bushels. 

 There was a loss of about 19/. in the former case and 

 a gain of about 17L in the latter. 



Ville's main thesis that crops can be grown with 

 chemical manures had already been demonstrated by 

 Lawes and Gilbert, with whose names it will for ever 

 be associated in England, and is now a commonplacei 

 in practical agriculture. His view that chemical 

 manures are in all circumstances better than dung has 

 not survived. He made no allowance for the won- 

 derful effect of the organic matter present in the dungi 

 in improving the texture and water-holding capacity 

 of the soil — an effect not shown at all, or even shown 

 in an adverse sense, by artificial manures. When we 

 remember how large a part of the farmer's labour is 

 devoted to cultivation it is easy to understand his 

 preference for dung. Indeed, on many soils addition 

 of organic matter is absolutely indispensable. Further, 

 it may be doubted whether we possess even yet the 

 data necessary for working out the relative costs of 

 farmyard and artificial manures in the complex, 

 conditions of modern farming, with its inter- 



