July 3, 1879] 



NATURE 



217 



properly recommends the consolidation of the land in 

 large farms, and the liberal use of artificial manures. 



The "normal manure" which M. Ville recommends is 

 in its simplest form a mixture of superphosphate, salt- 

 petre, and gypsum, thus supplying nitrogen, phosphoric 

 acid, potash, and lime. Instead of employing the nitrate 

 of potassium, a mixture of nitrate of sodium or sulphate 

 of ammonium with chloride of potassium may be substi- 

 tuted ; the manure then becomes a "normal homologous 

 manure." This normal manure embraces all the chief 

 elements of plant food which it may be necessary to apply 

 to the land. It is unnecessary, however, to apply the 

 entire mixture to every crop. Each crop demands a pre- 

 ponderance of one or other of the constituents of the 

 manure ; this " dominant " constituent is therefore in- 

 creased when the manure is prepared for a particular 

 crop ; or the elements of the whole manure may be dis- 

 tributed through a rotation of crops, each crop receiving 

 the part specially suited to it. Stated thus, we can only 

 approve the recommendations which M. Ville has made ; 

 they are in fact, in their last-named form, precisely carried 

 out by all our best farmers in the present day. Though, 

 however, we have correctly stated the teaching which 

 may be gathered from his book, there are many passages 

 in the lectures which urge the return to the land of all 

 the potash, phosphates, and lime which the crops have 

 removed, a proceeding which is on many soils quite un- 

 necessary, and therefore, very unremunerative. 



M. Ville recommends that each farmer should set aside 

 a small portion of his land to be treated with experi- 

 mental manures. One plot of this ground would receive 

 the normal manure ; a second the same without nitrogen ; 

 a third the same without phosphates ; a fourth the same 

 without potash ; while another plot would be left entirely 

 without manure. By growing crops on these plots the 

 farmer would learn in the most certain manner what ele- 

 ments of plant food were chiefly deficient in his soil in re- 

 lation to the crops he wished to grow. This is excellent 

 advice ; no better could be given. It is only by such 

 experiments that the true condition of the soil can be 

 revealed; and it is only by thus testing the effect of 

 manures before applying them on a large scale that an 

 economic return can reasonably be expected. France is 

 apparently ahead of us in the practical use of such experi- 

 ments. Thanks to the centralisation which places the 

 control of everything in the hands of the Government, 

 field experiments of this description are now in progress 

 in thirty-four farming schools throughout the country, 

 while simpler experiments on the effects of manures have 



I been established in connection with 350 day schools. In 

 England we have but one place at which such experiments 

 are thoroughly carried out, namely, Rothamsted. 

 Are we, then, to credit M. Ville with the discovery of the 

 great effect to be obtained from artificial manures, or of 

 the best mode of applying them ? He claims for himself 

 the honour of having discovered the principles he sets 

 forth, and compares himself with Lavoisier, and his de- 

 tractors with the detractors of that great man, and con- 

 cludes : — " We must allow time to complete the work of 

 justice, and give to every one his proper place." We 

 will in reply simply mention a few dates. The famous 

 field experiments at Rothamsted commenced in 1843 ; in 

 the very first year trials were made of the effects of phos- 



phates, potassium, magnesium, and ammonium salts. 

 These field experiments have been carried on continuously 

 up to the present time, and the effect of every variety of 

 combination of manure has been shown in the fields de- 

 voted to wheat, barley, beans, clover, roots, pasture, and 

 potatoes. That nitrogen should form the "dominant" 

 constituent of a manure for wheat, and phosphates the 

 dominant constituent of a manure for turnips, was clearly 

 proved in the first two or three years of the experi- 

 ments ; and by 1849 Ae character of potash as the proper 

 dominant in the case of beans and clover was also estab- 

 lished. With these experiments M. Ville is well ac- 

 quainted. Our last date shall be taken from his own 

 book. The first field experiments made by M. Ville at 

 Vincennes commenced in i860. 



The book contains several extraordinary statements. 

 It would take too long to discuss M. Ville's views as to 

 the assimilation of the free nitrogen of the air by all 

 crops, but especially by the leguminosae ; immense quan- 

 tities of nitrogen are, according to him, thus acquired. 

 We are curious to know what authority he has for stating 

 that when an animal is fed on hay one-third of the 

 nitrogen is lost "in the act of digestion," and that 

 another third is lost during the fermentation of the 

 animal manure, so that only one-third of the original 

 nitrogen is at last returned as manure to the land. 



We cannot conclude without calling attention to the 

 extremely untrustworthy character of the figures through- 

 out the book. On p. 54 the mould on an acre of soil 

 weighs 400,000 tons ; on p. 180 it weighs 1,600 tons. On 

 p. 353 the weight of resin yielded by an acre of pine trees 

 is given as 4-5 cwts., but immediately after it is stated 

 to be 1,122-1,540 lbs. The quantities of nitrogen to be 

 applied are a complete puzzle. To take a single instance : 

 On p. 238 we are told that to obtain a good crop of beet 

 we must apply 70 lbs. of nitrogen per acre. On p. 357 

 the quantity has risen to 176 lbs. On pp. 367 and 368 

 the formulae for the beet manures are given ; each formula 

 is stated to contain 187 lbs. of nitrogen; but on looking 

 at the ingredients only 83 and 85 lbs. of nitrogen are 

 found to be contained by the ammonium salts and nitrates 

 employed. Finally, on p. 374 we are told that the nitrogen 

 applied to beet should amount to 70-88 lbs. per acre. 

 What are we to believe ? 



Both the old and new chemical notations are employed 

 in the course of the book. R- W, 



OUR BOOK SHELF 

 Lecture on the Gault. By F. G. H. Price. (Taylor and 



Francis, 1879.) 

 This pamphlet contains considerably more than a lecture, 

 embodying a list of the French and English works upon 

 the Gault, which have come under the author's notice, 

 and nearly forty pages of tables of fossils. 



The description of the gault at Folkestone has been 

 amplified from that read by the author before the Geo- 

 logical Society. ' He maintains his subdivision of the gault 

 at Folkestone into beds, and endeavours to correlate with 

 them, to some extent, the gault to the west. The out- 

 crop at Eastbourne is separately described, and foiind to 

 contain an unexpectedly long list of fossils. The Black- 

 down beds are included in the Gault, which is to be 

 greatly regretted, for there is every reason to suppose that 



■ Quart, youtu. CeoU Sac, 1874, vol. xxx. p. 34s. 



