I 
 
 t>l , 
 
 riff : 
 
 tll> 
 
 \^:ri€iiltiir4^| , , 
 
 ■-I .totiias Jamlesoiij rxc, 
 
 Cf!«>a5SKif e;! l-RsseeMkde? »g "Stents 4|rfei)k'" 
 
Cornell University Library 
 S 455.J32 
 
 History of the progress of agricultural 
 
 3 1924 000 972 087 
 
HISTORY OF THE PROGRESS 
 
 OF 
 
 AGRICULTURAL SCIENCE 
 IN GREAT BRITAIN 
 
Cornell University 
 Library 
 
 The original of tliis book is in 
 tine Cornell University Library. 
 
 There are no known copyright restrictions in 
 the United States on the use of the text. 
 
 http://www.archive.org/details/cu31924000972087 
 
HISTORY OF THE PROGRESS 
 
 OF 
 
 AGRICULTURAL SCIENCE 
 
 IN GREAT BRITAIN 
 
 THOS. XA MIES ON, F.I.C. 
 
 DIRECTOR OF THE EESeXecH WORK OF THE AGRICULTURAL RESEARCH 
 
 ASSOCIATION, ABERDEEN 
 
 FORMERLY LECTURER ON AGRICULTURAL SCIENCE 
 
 ABERDEEN UNIVERSITY 
 
 CHEVALIER OF FRANCE "l'okDRE DE MERITE AGRICOLE" 
 
 PRINTED AND PUBLISHED BY 
 
 MESSRS. C. & R. ANDERSON 
 
 "NORTH BRITISH AGRICULTURIST" 
 
 EDINBURGH 
 
 May be purchased from Lewis Smith &= Son, Aberdeen 
 or through any Bookseller 
 
 Price— ONE SHILLING 
 
 S 
 
INDEX AND SUMMARY 
 
 INTRODUCTION 
 
 PAGE 
 
 Definition of Object in the History : — Limitation to Foundational 
 
 Facta in Agricultural Science discovered in Britain . . 7 
 
 I. EARLY WORK 
 Faulty, as Knowledge of Sgienoe limited ..... 9 
 
 1660 
 
 Sir Kenehn Digby — Discourse concerning the Vegetation of 
 
 Plants 9- 
 
 1738 
 
 Hales — Experiments on Vegetable Sap 9 
 
 1751 
 
 TuU — Principles of Vegetation and Tillage . . . .10 
 
 II. FIRST FOUNDATIONAL WORK 
 
 1774 
 
 Peiestlky — 
 
 Discovery of Oxygen . .12 
 
 Greatest discovery both in Chemical and Agricultural Scisnoe 
 First Guide to definite Progress in Science. 
 
 1772 to 1800 
 
 Gradual discovery of Carbonic Anhydride— or Carbonic Acid 
 
 Gas— 
 Priestley — Observed "Fixed" Gas arising from Fermentation. 11 
 Black — Observed same Gas set free from Chalk . . .11 
 Bonnet (Swiss) — Found a Gas arising from Plants under Water 12 
 Priestley — Found the Gas set free by Plants to be Oxygen . 1 2 
 Ingenhousz — Found the Oxygen given off by Plants only 
 
 under Sunlight . . . . . . . . 12 
 
VI 
 
 PAOH 
 
 P«mi>aZ— Found the "Fixed " Gas served to feed Plants . 12 
 
 Senebier (Swiss)— Found the " Fixed " Gas was the source of 
 
 the Oxygen given off by Plants, that the "Fixed" Gas 
 
 was decomposed by them, its Carbon being retained, and 
 
 its Oxygen set free to Air, thus completing the discovery 
 
 of Carbonic Acid Gas 12 
 
 As by far the largest proportion of Plant Matter consists of Carbon, 
 Hydrogen, and Oxygen, and as Water provides the Hydrogen and 
 Oxygen, the provision of Carbon to Plants by Carbonic Acid Gas in 
 Air, explained, at this early period, the source of all Organic Plant 
 Matter, except Albumen. The source of the Nitrogen in Albumen 
 remained a mystery till 1905. 
 
 in. ROUSING PERIOD 
 Publications, Lectures, etc. Few or no new facts ... 13 
 
 1795 
 
 Earl Dundonald wrote, Coniiection between Agriculture amd 
 
 Chemistry 13 
 
 1800 to 1832 
 Sir John Sinclair — 
 
 Established Temporary Board of Agriculture . ... 14 
 Attempted to establish Experimental Farms and Agricultural 
 
 Professorships 14 
 
 Appointed Writers on Agricultural Subjects : Young, Elkington 14 
 Wrote Code of Agriculture (1819) . . . . . .15 
 
 Appointed Lecturer on Agricultuial Subjects : Sir H. Davy . 16 
 Sir H. Davy wrote. The EUmentB of Agricultural 
 
 Chemistry (1813) 16 
 
 1766 
 
 St. Leger — Observed great Effect of Phosph'ate on Plants . . 15 
 
 1828 
 
 Doncaster Agricultural Society — Inquired into and published 
 
 eCfect of Phosphate 15 
 
 1840 
 
 British Association or Advancement of Science — 
 
 Appointed Liebig: o lecttire on Agricultural Subjects . . 16 
 
 Liebig's Publications 17 
 
 Liebig's chief Doctrines — 
 
 Rejection of " Humus " Theory 17 
 
 Minerals essential to Plants 17 
 
 Production largely regulated by Mineral Provision . . 17 
 
 Plants get Nitrogen from Ammonia in Air (error) . . 17 
 
 Plants excrete Matter . . , . ,v . ,■ . 17 
 
IV. GRADUAL ELUCIDATION OF THE MINEEAL ASPECT 
 OF PLANT FOOD 
 
 1840 
 
 PAGE 
 
 Liebig — Showed how Insoluble Phosphate might be rendered 
 
 soluble by Sulphuric Acid 18 
 
 Lawes — Followed up Liebig's guidance by taking out Patent for 
 
 Superphosphate 19 
 
 1841 
 
 Johndon — First Methodical Treatment of Agricultural Science in 
 
 2%e Elements of Chemistry amd Qeology . . . . 20 
 
 Finnic — Instituted "Chemical Association of Scotland" which 
 
 stimulated Agricultural Inquiry through Johnston . . 20 
 
 V. NATIONAL AGRICULTURAL SOCIETIES 
 
 Gave little attention to Original Inquiry — none to Science — some 
 Aids to Practice through Annual Papers by the Society's 
 Chemists and Botanists 22 
 
 Royal Ageicultuiial Society of England — 
 A. Voelcker — 
 
 Composition of Turnips 23 
 
 EflFect of different Foods on Cattle 23 
 
 Effect of Phosphates as Manure 23 
 
 Ineffectiveness of Insoluble Phosphate .... 23 
 
 J. A. Voelcker — Trials with Lithium and Manganese . . 23 
 
 Highland and Agbioulttteal Sooibty of Scotland — 
 
 Anderson — Composition of Plants at different stages . . 23 
 
 Aitken — 
 Effect of Phosphates — Confirming effectiveness of Insoluble 
 
 Phosphate found at Aberdeen 23 
 
 Methods of Turnip Cultivation 23 
 
 Different Cattle Foods and Methods of Feeding ... 23 
 
 Milne — 
 
 Effects of various Cattle Foods 23 
 
 Effect of various Fodders on Cattle 23 
 
 Increase in Cattle Weight at different ages .... 23 
 
 Wilson — Comparative Produce and Value of Grasses . , 24 
 
 VI. FURTHER FOUNDATIONAL WORK 
 
 Continuation of Section 11 25 
 
 1840 to 1850 
 
 Power of Soil to absorb Compounds of Mineral Elements 
 essential to Plants, i.e. Phosphorus, Potassium, and 
 Nitrogen (as Ammonia). Useless materials allowed to 
 escape — also Nitrates ^ . 25 
 
 Supposed Mode of Absorption — Formation, of Double 
 Silicates 26 
 
VIU 
 
 1857 
 
 PAOS 
 
 Cameron— Found that Plants can utilise Nitrogen in Urea . 25 
 Summary of Foundational Work up to 1850 .... 26 
 Retrospect 27 
 
 1846 
 
 Daubeny — 
 Supposed that Food available in Soil is quantity dissolved 
 
 by Carbonic Acid 29 
 
 Supposed that Plants do not excrete 29 
 
 1843 
 
 Lawes— Started Field Trials— Faulty System . . . SO 
 
 VII. WORK AT ROTHAMSTED 
 
 General character of Large Field Trials 28 
 
 Liebig's condemnation of Methods and Conclusions . . 32-33 
 Classification of Work at Rothamsted 33 
 
 1843 to 1910 (proceeding) 
 
 (a) Most useful Results — 
 
 By Lawes, Gilbert, Pugh, and Warrington. 
 
 Confirmation of and Additions to Nitrification .... 39 
 
 Determination of Ammonia and Nitric Acid in Air ... 40 
 
 Determination of Losses and Gains of Nitrogen .... 40 
 
 Confirmation of " Way's " Results 42 
 
 Incidental confirmation of Absorption of Nitrogen in air by 
 
 Plants 42-43 
 
 Cattle-Feeding Trials 46 
 
 (6) Subordinate Results — 
 
 Large Trials on Complete and Partial Manuring . . .48 
 Conception faulty, Manure heavy and unsuitable. Soil 
 dragged. Plants unhealthy. Crops poor, Conclusions in- 
 applicable to Science and Practice 48 
 
 Hutchinson and Russell — Current Trials — Suggestion that 
 Fertility of Soil is regulated by the proportion of certain 
 Bacteria. Criticism 63 
 
 VIII. AGRICULTURAL RESEARCH ASSOCIATION, 
 ABERDEEN 
 
 1875 to 1910 (proceeding) 
 
 General character of Work 72 
 
 (a) Chief Results 74 
 
 Jamieson — 
 Ability of Plants to utilise Mineral Insoluble Phosphate 
 
 of Lime .... 77 
 
IX 
 
 PAOX 
 
 Aperture at extremity of Root Hairs by which Insoluble 
 
 Matter is absorbed 79 
 
 Primary cause of Turnip Disease and its Beraedy ... 82 
 
 Physical features of Soil regulating Fertility .... 84 
 
 Self-cross Fertilisation of Cereals and Grasses .... 86 
 
 Method of Reproduction of Cereals and Grasses— true Stigma . 89 
 
 Permanence of Rye Grass — Degenerated Form and Plasticity . 91 
 
 Reduction in number of Minerals essential to Plants , . 93 
 Direct Absorption and Utilisation of Free Nitrogen in air by 
 
 Green Plants 95 
 
 (i) Subordinate Results — 
 Detei-mination of relative effects of Manures, of Composition of 
 Crops, of Productiveness of Grasses, Methods of Harvest- 
 ing and Preserving Crops, etc. 76 
 
 GENERAL REFERENCES 
 
 Retarding Influence on Progress of Dogma and Authority 
 
 78, 80, 86, and 95 
 Three Circulations in Nature of Matter connected with Plant 
 
 Life . . . . Ill 
 
 Prospects of Progress in Agricultural Science . . . .113 
 
EDITORIAL NOTE 
 
 It is a remarkable fact that much as we hear 
 about agricultural science, it is regarded more 
 or less as a mysterious matter by those whom 
 it is intended to benefit. It is not known very 
 clearly what it consists in, nor how precisely 
 help is to be derived from it, and there is still 
 less acquaintance of when, how, and by whom 
 the facts forming the science have been accumu- 
 lated. This is not as it should be. It should 
 be possible to state simply and clearly what is 
 the real outcome of at least any completed 
 work. For what is not simple is not science. 
 So long as a subject is in the imperfectly known 
 stage, it can only be obscurely treated, and is 
 better not to be set forth to the uninitiated ; but 
 when it has reached the stage of being reliably 
 proved, and can thus be regarded as science, it 
 should admit of such clear statement as to be 
 generally understood and acted upon. 
 
 This desirable object may possibly now be 
 so far attained as the result of the action of an 
 agricultural department of the French govern- 
 ment which publishes a work called the Annales 
 de la Science Agronomique, the administration 
 having requested Mr. T. Jamieson, Aberdeen, 
 to give a brief " History of the progress of 
 Agricultural Science in Great Britain." We 
 have had the privilege of seeing this work in 
 French, and while it will be impracticable to 
 insert a translation of it in our columns in full, 
 we propose to give what may,be called a practical 
 outline of the earlier progress up to the time 
 when, by improved methods, agricultural 
 science proper may be said to have begun in 
 
Qreat Britain. This really brings us up to 
 comparatively recent times, and notably to 
 the work at Bothamsted. With that work, 
 and contemporary work, such as that at Aber- 
 deen, we propose to deal as fully as possible, 
 because it is set forth in the history in such 
 a summarised way that the outstanding features 
 may be readily grasped without the detail 
 that many have neither the desire nor the time 
 to study. 
 
PROGRESS OF AGRICULTURAL 
 SCIENCE m GREAT BRITAIN. 
 
 INTRODUCTION. 
 
 It is not a formidable undertaking to write 
 a history of the progress of agricultural science 
 in the United Kingdom of Great Britain and 
 Ireland, because not only is the birth of that 
 science comparatively recent, but the govern- 
 ment of that nation is almost alone among 
 European nations in giving it no assistance. 
 It leaves agricultural research almost entirely 
 to individual effort, and hence the contributions 
 of Britain to agricultural science are compara- 
 tively few in number, or at least not such as 
 they might have been. 
 
 A retrospect of the dawn of agricultural 
 science is interesting ; it brings out the early 
 aspirations to solve the mysteries of nature, 
 the gropings to do so under the very dim light 
 at that time available, and the consequent 
 curious effects ; they resemble the distorted 
 impressions given under the obscurity by mist 
 on a mountain that amuse when the haze is 
 cleared away. 
 
 It is proposed here to deal only with the 
 progress of agricultural science proper, and to 
 limit reference to what has actually been 
 done in this country ; hence the practice of 
 agriculture is not treated beyond indicating 
 that it has advanced, like that of other countries, 
 from the crude methods, homely implements, 
 and poor cattle to the higher methods of cultiva- 
 tion, to advanced modern implements, to pure 
 breeds, and the use of artificial manures and 
 foods. Not is agricultural education treated 
 because it cannot be regarded as an advance of 
 agricultural science, but rather an advance 
 in the general knowledge of it. Literature 
 also ia referred to only briefly as it is largely 
 ' 7 
 
educational, and prominence is given only to 
 those publications that mark an advance in 
 science. There is even another aspect that 
 is excluded, viz., scientific work that does not 
 effect any advance nor the introduction of 
 any new principle, but rather provides facts 
 bearing on, and foUowing up principles already 
 found. In this category fall the numerous 
 analyses of soils, manures, foods, crops, etc., 
 which have formed, and still form, a very large 
 part of the work of agricultural scientists. 
 
 By the exclusion of these branches the history 
 is greatly simplified ; it leaves to be set forth 
 only the discoveries of foundational facts that 
 form, or help to form, the doctrines which 
 constitute the principles or science of agri- 
 culture. 
 
EARLY WORK. 
 
 The work of early times may be dealt with 
 shortly, because the methods employed at that 
 time were in most oases faulty, and the results 
 must therefore be rejected. There are, however, 
 exceptions to this, for even in that period some 
 important and even brilliant resulte were got, 
 which have stood the test of time, and still 
 stand out as foundational stones of the edifice. 
 
 A century ago agricultural science was not 
 known in the ^ngdom ; some important facts 
 had been discovered, but they were known to 
 few. For half a century after that time so 
 little advance was made that we have only to 
 go back about fifty years to find the clear recog- 
 nition in this country of the application of science 
 to agriculture, and only in the latter part of 
 that period did the subject receive anything 
 but desultory attention. Even yet a very 
 limited number are engaged in agricultural 
 research. 
 
 Probably the first work of any merit on 
 agriculture published in Britain was that of 
 Sir Kenelm Digby (1660), entitled A Discourse 
 concerning the Vegetation of Plants. The title 
 itself in<Ucates an aspiration to know hidden 
 truths. He attributed plant growth to a 
 " balsam " in the air. Trying to define the 
 " balsam," he speaks of the good efiect of what 
 he calls " digested dew," and indicates that it 
 contains a nitrous salt; but while ascribing 
 to that salt much value (as proved by the use 
 of saltpetre) he regards it as a magnet which 
 attracts hidden food for plants in the air ! Crude 
 as all this is, it is surprising how it foreshadows 
 the discovery of the power of carbonic acid 
 and nitrogen in air, with water, to form plant 
 matter. 
 
 Hales published a work in 1738 entitled 
 Experiments on Vegetable Sap. The title here 
 also indicates the desire for inner knowledge. 
 9 
 
10 
 
 This work refers chiefly to the motion of vege- 
 table sap, and to the effect on it by light, and 
 also the effects by different treatments of the 
 roots ; but his ideas, formed under vague know- 
 ledge, are greatly modified by modern inquiry, 
 and cannot be regarded as providing any firm 
 stepping-stone. 
 
 Another early work of some notoriety is 
 the quaint and shrewd writings of Jethro TuU 
 (1751), whose work was at that time deemed 
 so valuable that it ran through at least three 
 editions. Evidently he was intimate with the 
 practice of agriculture, and sought to advance 
 it by insisting on the theory that constant 
 stirring of the soil is the main essential to success- 
 ful cultivation, and that this alone suffices 
 without any manure ; but although he gives 
 his work the pretentious title of An Essay on 
 the Principles of Vegetation and Tillage, he evi- 
 dently was utterly ignorant of science, and 
 yet pronounces on it with an assurance that is 
 amusing, as is shown, for instance, in the follow- 
 ing passage on the action of nitrates, and which 
 is akin to many other passages : " Nitre is 
 useful to divide and prepare the food, and may 
 be said to nourish vegetables in much the same 
 manner as my knife nourishes me by cutting 
 and dividing my meat. But when Nitre is applied 
 to the root of a plant, it will kill it as certainly 
 as a knife misapplied to a man.' Which proves 
 that Nitre is, in respect to nourishment, just 
 as much food of plants as white arsenic is the 
 food of rats." Such passages, while amusing, do 
 not surprise, for it is a remarkable fact that in 
 this the twentieth century, so little has agri- 
 cultural education permeated the mass, many 
 farmers of the present day would be disposed 
 to agree with Jethro TuU. 
 
11. 
 
 FIRST FOUNDATIONAL WORK. 
 
 It la not till 1774 that we come to any firm 
 step in agricultural science, and before the 
 century was completed some bright gems were 
 brought forth in the form of important founda- 
 tional discoveries that have stood the test of 
 time. 
 
 In 1772 several men made earnest efforts to 
 get some definite information regarding the 
 atmosphere, and notably Joseph Priestley of 
 London. Knowing no other ga? than air, 
 which allowed a light to burn in it, he was sur- 
 prised to find that the air arising from fermenta- 
 tion would not support combustion. Over 
 this substance, which he called " fixed air," 
 he struggled for a long time to ascertain its 
 nature, under the great diffloulties presented 
 by total ignorance of the nature of the atmo- 
 sphere ; accidentally he found, after many 
 trials with other materials, that plants acted 
 upon this " fixed air " in such a way as enabled 
 it to support combustion ; he regarded it as a 
 purifier of the air ; he failed, however, to find 
 what the gas really was, which we now know 
 to be carbonic acid, and he did not realise that 
 the effect which he observed on it by plants 
 was produced by its decomposition, and the 
 subject fell to be finally elucidated by others. 
 Knowing the facts now, we are disposed to 
 smile at these early perplexities, until we reflect 
 how very mysterious many simple things are 
 until elucidated, and how very difficult often is 
 the elucidation. It should be recorded that in 
 these perplexing trials with carbonic acid, 
 simultaneous work was done by others, viz. 
 by Hales and Cavendish and by Black of Edin- 
 burgh, who first discovered that the " fixed 
 air " existed in chalk and other carbonates. 
 About the same time Priestley worked earnestly 
 to discover the nature of acid (or nitrous) gases 
 and alkaline gas (ammonia), but beyond reoog> 
 
12 
 
 nisi:^ some of their remarkable actions, he 
 failed to find, and could scarcely, under the 
 limited knowledge of the time, have been ex- 
 pected to find, their real nature. 
 
 In 1774 " Priestley " gave an extraordinary 
 impetus to science in all its branches by his 
 most important discovery of the element oxygen, 
 one of the most abundant and general, and also 
 one of the most active and important elements 
 in nature. Sometime after, Lavoisier " (the 
 eminent French chemist with whom Priestley 
 was in communication) named it oxygen, i.e. 
 I give rise to acid. Then came a period of 
 many workers bearing on the relation of oxygen 
 to carbonic acid. Priestley found that the 
 bells of air that had been discovered by "Bonnet" 
 in Switzerland to arise from leaves when im- 
 mersed in water, were composed of oxygen. 
 In 1779 " Ingenhousz " in England advanced 
 another step by finding that this gas was gij'en 
 out by plants only under sunlight ; Percival 
 continued the onward progress by finding that 
 carbonic acid served as plant food ; and the 
 final step was gained by another Swiss — Senebier 
 — who found (in 1800) that the source of the 
 oxygen given off by plants was the carbonic 
 acid in wie air, which was decomposed by plants, 
 and its carbon assimilated. These signal early 
 advances make one pause, with a feeling of 
 no little admiration, satisfaction, and gratitude, 
 though we have to introduce and acknowledge 
 aid from the Continent to complete, and indeed 
 largely make, the discovery. Here we have 
 the discovery of oxygen, then of carbonic acid, 
 then that this carbonic acid gas in air feeds 
 plants with carbon, and finally that the plants 
 liberate from it the oxygen on which animals 
 depend. The discovery of these truths mark a 
 glorious epoch in agricultural science ; they 
 provided facts that served as master-keys in 
 the further developments of the principles of 
 a.griculture. They give the foundation to the 
 later developments of the fact that plant matter 
 is almost entirely derived from air and water, 
 and but little from the soil. 
 
m 
 
 BOUSING PERIOD* 
 
 Now it is a most lemaikable ciroumstance, 
 and one which shows how lamentably agri- 
 cultural education has failed to permeate the 
 mass, that these facts, discovered more than 
 a century ago, are not known to perhaps 99 
 per cent, of agriculturists. The general oelief 
 still is that the soil feeds the plants ; the rich- 
 ness or poorness of soil is still a prominent factor 
 in considerations of cultivation, although the fact 
 is that only about 1 per cent, of the plants grown 
 really come from matter in the soil. 
 
 We iave to pass over a long period before 
 anything so foundational was discovered. This 
 shows how much advance depends on individual 
 initiative. Indeed, forty years elapsed before 
 anything new and important that could be called 
 scientific, appeared on the scene. During that 
 period no doubt several very noteworthy works 
 were published, which aimed at advance in agri- 
 culture, but they dealt chiefly with methods of 
 practice while showing a faint stretching out to 
 science as a hidden region of promise. Two of 
 these works or efforts deserve special notice. 
 
 It is to a Scottish hobleinan, the Earl of 
 Dundonald, that is due the production of the 
 first book in the English language on agricul- 
 tural chemistry, such as it was. In 1795 he 
 published a work entitled A Treatise shewing 
 the Intimate Connection that Subsists between 
 Agriculture and Chemistry ; but, as at that time 
 even the chemical nature of the atmosphere, 
 and of water, had been but recently discovered, 
 it is obvious that the chemistry given was but 
 scant and faulty. This is borne out by his 
 explanation xii the composition of plants, which 
 is as follows : " Vegetables consist of mucilagih- 
 13 
 
14 
 
 ous matter, resinoufl matter, matter analogous 
 to that of animals, some proportion of oil, and 
 earthy matters formerly held in solution in the 
 newly taken in juices of the growing vegetables." 
 Evidently he recognised material action by the 
 air, and he makes the bold statement that plants 
 " are composed of gases with a small proportion of 
 calcareous matter." 
 
 It is to another Scotchman, however, that 
 the first impulse towards the recognition of 
 agricultural science, properly so called, was 
 made in this country. Sir John Sinclair in- 
 fluenced the Government to establish a Board 
 of Agriculture (which, however, had but a short 
 existence), and although the main object of that 
 Board was to encourage and assist drainage 
 and enclosures, yet he evidently had a conviction 
 of the benefit attainable from science, as he pro- 
 posed the establishment of not only a system 
 of collection and diffusion of useful information, 
 but also of experimental farms, and of agri- 
 cultural professorships. In the collection of 
 information in regard to methods of cultivation 
 in use, he did excellent service by getting a 
 number of men to write an account of the systems 
 of agriculture in numerous counties in England 
 and Scotland, the most notable of whom perhaps 
 was Bev. Arthur Young, and also Elkington, 
 who wrote specially on drainage. Altogether 
 forty-seven volumes were printed relating to 
 England, and thirty relating to Scotland, and 
 it is stated that " no subject had ever before 
 been so thoroughly sifted." These writings 
 on the agriculture of the various countiep (1808) 
 were gathered up and added to in^ a volume 
 written in 1819 by the instigator himself and 
 founder of the temporary Board of Agriculture 
 — Sir John Sinclair — entitled The Oodt of Agri- 
 cultwe, a large work evincing enormous labour, 
 which was so valued that several editions were 
 called for, the fifth edition being published in 
 1832 in the seventy-ninth year of the author's 
 age. Most ably written as many of the separate 
 articles were, and especially the " Code " itself, 
 considering the knowledge available at that 
 time, yet essential errors are obvious by the 
 want of accurate knowledge due to comparative 
 neglect of any scientific inquiry. How little 
 was known at that time about science is shown, 
 for instance, by Young's work on The Science 
 
16 
 
 of Agrievlture, who in describing manures 
 used does not even mention phosphates, 
 potash, or nitrogen by which manure is now 
 identified; and while the effect of these sub- 
 stances was experienced in using wood ash, 
 peat ash, dung, urine, etc., the virtue was 
 ascribed to these substances as a l^ind of specific, 
 without any attempt to define to what ingredi- 
 ents in the mass the effect was due. The same 
 view was talien even of bones, and that even 
 when it became Isnown that they were highly 
 phosphatic. Their extraordinary effect was 
 discovered by Mr. A. St. Leger in Yorksliire in 
 1766, but the subject did not attract much 
 public attention till 1828, when the Doncaster 
 Agricultural Society inquired into it and gave 
 pubUoity to the effect. Even then, although 
 a chemical analysis by Berzelius showed that 
 bones contained over 50 per cent, of phosphate 
 of lime, yet it was to bones, as bones, that the 
 effect was ascribed, and it was even attempted 
 to be explained, though most vaguely, by 
 Sinclair in nis " Code " of 1832 as follows : — 
 
 "It is difficult to comprehend how so small 
 a quantity of manure as that employed when 
 bones are made use of, should produce such 
 astonishing effects. But the enigma has been 
 thus explained. Though the plants receive 
 but a small portion of benefit from the bone 
 manure itself, yet by means of that manure, 
 strong young plants are produced, which are thus 
 rendered capable of extracting nourishment 
 from the substances in which they are placed, and 
 from the surrounding atmosphere." 
 
 These were the days when manure had a 
 broader and less specific acceptation than holds 
 good now. Manures included " all those sub- 
 stances which, when artificially applied to or 
 blended with the soil, are known from experience 
 to restore, to preserve, or to augment its fertility, 
 or to render it, in any other respect, more favour- 
 able to vegetation. This includes all the articles 
 which tend to correct any noxious ingredients in 
 the soil, or to return to greater utility, certain 
 substances previously contained in it." They 
 were classified into " Putrescent, Calcareous, 
 Earthy, Vegetable, Miscellaneous, and Composts, 
 and while the " Putrescent " (i.e. dung, night 
 soil, urine, fish, etc.) were regarded as the most 
 important, yet the " calcareous " {i.e. lime, marl, 
 shells, gypsum, etc.) was of much more general 
 application than now prevails. 
 
16 
 
 Although Sinclair failed to found experimental 
 farms and Agricultural Professorships, yet he 
 managed to secure the services of an eminent 
 scientific man, Sir Humphrey Davy, to give 
 lectures for the Board ; these lectures were 
 commenced in 1802 and continued for ten 
 years. The selection of Davy was fortunate, for 
 few at that time had the soientiflc attainments 
 fitted to give so powerful an impulse as was 
 given by him. His brilliant lectures, based on 
 reliable scientific facts — not a few of which had 
 been discovered by himself — gave an impetus 
 to intelligent thought, and his published work. 
 The Mements of Agricvlturcd Chemistry (1813), 
 happily sustained that effect and led to further 
 development. Although his conclusions in many 
 cases are now known to be erroneous and 
 exaggerated, yet hia main ideas were sound, and 
 his masterly treatment of them was inspiring. 
 His treatment was necessarily incomplete, it 
 was largely a history of the progress, and the 
 expression of the promise resulting from the 
 development of Agricultural Science ; but it had 
 a remarkable effect, though it was not directly 
 acted upon conspicuously for many years 
 in Britain, during which time important work 
 was being done on the Continent, mainly by 
 De Saussure and Boussingault. 
 
 In 1840 the " British Association for the 
 advancement of Science " gave another stimulus 
 by inviting Justus von Liebig, Professor of 
 Chemistry in Heidelberg, to write a treatise on the 
 application of Science to Agriculture. It is 
 doubtful if he would have attained his eminence 
 as an Agricultural Chemist but for this invitation. 
 Perhaps no happier choice could have been 
 made than that of Liebig ; a slulled chemist 
 who had himself conducted many original 
 investigations bearing on Organic Chemistry, 
 with a strength of character, a power of keen 
 and broad observation, a tendency to apply 
 knowledge to practical purposes, and a clear, 
 fluent, and confident style of expression, he 
 was eminently fitted to treat the subject in as 
 masterly a way as could be done at that time. 
 Strictly scientific, and intensely practical as he 
 iras, it is hot surprising that some of the laboratory 
 methods which he proposed are used to the 
 present day, and that commercial enterprises 
 based on his recommendations still continue to be 
 
17 
 
 carried out in a large scale, for instance, the 
 industry of the extract of meat, and of the 
 huge manufacture of superphosphate. His re- 
 sponse to the invitation of the British Associa- 
 tion took the form of Lectures, which were 
 published in 1840 under the title of Chemistry 
 in its application to Agriculture and Physiology ; 
 followed in 1842 by Animal Chemistry ; in 
 1855 by Principles of Agricultural Chemistry ; 
 in 1856 hy The Theory and Practice of Agriculture ; 
 and in 1863 by The Natural Laws of Husbandry, 
 though to some extent these works are repeti- 
 tions. 
 
 His main contentions were (1) the rejection 
 of the so-called Humus theory (which had already 
 been exposed by Continental chemists) and the 
 substitution of the fact (discovered by Percival 
 and Senebier) that plants derive their carbon- 
 aceous matter not from the " humus " of the 
 soil but from the carbonic acid of the air ; 
 and (2) his strong advocacy of the " mineral 
 theory " (the foundation of which most im- 
 portant doctrine had been discovered by the 
 French scientist " De Saussure ") that small 
 as is the proportion of minerals in plants, yet 
 that not only are they absolutely essential, but 
 that successful cultivation depends largely upon 
 their provision. He carried the latter point 
 too far, by insisting not only that the atmo- 
 sphere provided to plants their Carbon, which 
 was admitted, but also their Nitrogen, which 
 turns out apparently to be correct, but he erred 
 in holding that such Nitrogen was provided by 
 the Ammonia in the air. In this he was misled 
 not by his own work, but by the work of others 
 who had far over-estimated the amount of 
 Ammonia in air, and in rainfall. It ia now known 
 that it, along with other qombined forms, 
 amounts to at most 6 lbs. to an acre per year, 
 while crops contain often over 50 lbs. per acre. 
 Still, Liebig was satisfied, from his general and 
 shrewd observations, that somehow or other 
 plants did get their nitrogen from the air ; but 
 being unprovided with proofs, and being further 
 misled by the conclusions of Boussingault to 
 believe that plants are unable to absorb nitrogen 
 in its free state from air, he adhered to his belief 
 in their provision by Ammonia. 
 
 Another prominent feature of liebig's writings 
 was his advance of the " excretion theory." He 
 felt satisfied that plants excreted by their roots 
 material which is injurious to themselves, and 
 that this explained the'need and the benefit of a 
 
 3 
 
18 
 
 rotation of crops. It cannot yet safely be said 
 that he was wrong in this conclusion, for most of 
 the evidences we have on the subject really are 
 in favour of such excretion; and it only happens 
 that as the one or two evidences to the contrary 
 were the latest, they have become accepted as 
 doctrines which now prevail, but may yet 
 have to be modified. 
 
 Liebig's strong convictions from substantiated 
 facts, combined with a very lucid and forcible 
 style of expression, had a powerful effect, 
 especially as the way had already been paved 
 by Sir H. Davy, and although, as is now known, 
 some error ran through many of his arguments, 
 yet, in the main, his conclusions are still re- 
 garded as sound, and his teaching forms the 
 basis of many of the doctrines on plant life now 
 existing. His error with regard to Ammonia 
 in air brought him seriously into conflict with 
 Mr. John B. Lawes, a wealthy farmer who had 
 just started experiments at Rothamsted. 
 Liebig's contempt for these experiments, based, 
 as he showed them to be, on unscientific and 
 ridiculous grounds, caused him to speak in 
 unreserved terms, but his own misconception 
 in regard to Ammonia (though Lawes was also 
 wrong) placed him at some disadvantage, 
 and therefore perhaps his condemnation on 
 scientific grounds of the Rothamsted work 
 had less effect than it would otherwise have 
 had. 
 
 It will be seen that Liebig's work in Britain 
 v/as not so much the production of any fact 
 (for the " humus " theory and the " mineral " 
 theory had been dealt with by several con- 
 tinental Scientists), but rather in expounding 
 the position of agricultural science, and insist- 
 ing on it with a force that had not before been 
 applied. He carried out numerous investiga- 
 tions in organic chemistry, but so far as original 
 work bearing on agriculture is concerned,- per- 
 haps the only outstanding work is his recogni- 
 tion — ^it can hardly be called a discovery— that 
 insoluble phosphate is rendered soluble by 
 acid, and seeing its utility to agriculture he 
 advised it — advice which was acted on by 
 Mr. Lawes of Rothamsted, and by which he 
 made his fortune — and the result of Liebig's 
 suggestion is the manufacture of superphos- 
 phate which is now carried out on a gigantic 
 scale. 
 
 The originator of the name " Superphosphate " 
 WIS a schoolmaster in Aberdeenshire — Mr. W. 
 
19 
 
 Hay, Tillydesk, Ellon. He was among the 
 first to use it, and we have a vague recollection 
 that Mr. J. B. Lawes had to arrange with and 
 compensate him in taking out his patent for 
 the sole sale of superphosphate. 
 
IV. 
 
 GRADUAL ELUCIDATION OF THE 
 MINERAL ASPECT OF PLANT FOOD. 
 
 There was no need to send to Germany for 
 a chemist to enlighten British agriculturists, 
 for there was at least one man in the Kingdom, 
 viz. Professor Johnston of Durham University, 
 who was perhaps equally capable, and was much 
 more intimate with British agriculture, but he 
 would have lacked the glamour that attends a 
 stranger, and probably Liebig's lectures went far 
 to stimulate Johnston — a year later — to provide 
 the defloienoies of Liebig's lectures, which of 
 course, were not intended to present a complete 
 account of agricultural science, even as it was 
 then known. 
 
 Professor Johnston had the distinction of 
 publishing (in 1841) the first work in Britain 
 that can be regarded as a complete methodical 
 treatment of agricultural science. His efforts 
 to advance and to stimulate the application 
 to practice of agricultural science were largely 
 aided by a Scotchman, Mr. John Finnic of Swans- 
 ton, who initiated a " Chemical Association of 
 Scotland," by which an income of £700 was 
 raised for several years. Professor Johnston's 
 voluminous work, entitled The Elements of 
 Chemistry and Geology, was a masterly treatment 
 of the subject, based on scientific data largely pro- 
 vided by his own work ; it was fully detailed, and 
 was expressed in a manner both lucid and suited 
 to the unscientific. The merit of that work 
 is shown by the facts that, in an abridged form, 
 it has run through no less than seventeen editions, 
 edited first by Sir Charles Cameron of Dublin, 
 and latterly by Dr. Aikman of Glasgow, and 
 that the latter edition, published in 1894, ad- 
 justed and brought up to the present time, 
 constitutes even now, perhaps, the most 
 satisfactory and reliable mannal on agricultural 
 science used in the kingdom. If to that work is 
 added the work entitled Manures and Manuring, 
 
 20 
 
21 
 
 by Dr. AikmaD of Glasgow (1894), in which 
 the foundational features of the nourishment 
 of plants are ably set forth, the general student 
 of agricultural science is well provided, though 
 advantageous additions would be Chemistry 
 of the Soil, by Warrington, in which work his 
 special inquiries are more fuUy discussed ; by The 
 Laboratory Ouide for Agricultural Students, by 
 A. H. Church, in which analytical methods 
 are ably treated ; and by the work entitled 
 Agricultural Analyses by Professor P. Frank- 
 land. No doubt there is a large number of other 
 works, ancient and modern, on agriculture, 
 but while some are antiquated, aU of them, and 
 especially the larger works, deal more with 
 agricultural practice than with science. 
 
V. 
 
 WORK BY NATIONAL SOCIETIES. 
 
 A^'TiiR these rousing efforts by Davy, Liebig, 
 and Johnston, the progress in agricultural 
 science was very slow and of little importance 
 for a long time. There was no national support 
 or encouragement for such work, nor was there 
 any combination out of which such work might 
 be expected to arise. On the contrary, the 
 three leading agricultural societies, having 
 altogether different objects in view, rather dis- 
 couraged or looked askance on scientific work ; 
 and as the genera] public looked to them for 
 general progress, their existence had the effect 
 of diverting attention from agricultural research, 
 an idea which was strengthened by the fact that 
 one or two scientific men were associated with 
 these societies who might be expected to do all 
 that was necessary. But, poorly remunerated 
 by the societies, and much engaged in more re- 
 munerative work as they were, little was really 
 to be expected. It is not surprising, therefore, 
 that no foundational fact in science was brought 
 to light by any of the three large agricultural 
 societies in the -United Kingdom, viz. The Royal 
 Agricultural Society of England, the Highland 
 and Agricultural Society of Scotland, and the 
 Agricultural Society of Ireland, but touching 
 on science as they did, their actual work should 
 be recorded. The main object of these societies 
 is to hold the usual exhibitions of cattle, horses, 
 implements, etc., with the view of encouraging 
 and advancing the breeding of animals, and to a 
 less extent of stimulating advance in mechanical 
 methods of cultivation, and their income is 
 mostly expended on such exhibitions and on 
 prizes to breeders. The work of their consult- 
 ing chemist and consulting botanist- has con- 
 sisted largely in consultation, the analysis 
 of soils, manures, and foods for the guidance 
 of farmers, and in making reports or articles 
 annually on some agricultural subject of interest, 
 
 3-2 
 
23 
 
 These reports are embodied in the" transactions " 
 of the respective societies. Occasionally, how- 
 ever, these scientists made some field experiments, 
 such as (1) those of the English Society at 
 Woburn conducted by Dr. A. Voelcker, and 
 latterly by Dr. J. Voelcker, which were intended 
 chiefly to check the experiments at Rothamsted ; 
 but it shows the limited interest in science of 
 these societies, that those trials were conducted 
 at the instance of, and at the cost of, the Duke 
 of Bedford ; and (2) those of the Scottish Society 
 near Edinburgh conducted firat by Dr. Thomas 
 Anderson (who determined the composition of 
 plants at different stages, chiefly of turnip, bean, 
 and wheat); and finally by Dr. A. P. Aitken, whose 
 trials were stimulated into existence by, and 
 intended chiefly to check, the results of the ex- 
 periments, of the Research Association at Aber- 
 deen. These results being confirmed, he directed 
 his attention to methods of turnip cultivation, 
 to inquiries into the comparative effect of 
 different foods for cattle and different methods 
 of feeding, etc. But his trials were poorly 
 supplied with funds, frequently deprecated by a 
 society that had little sympathy with science, 
 and ultimately were stopped. 
 
 Dr. A. Voelcker co-operated generally with 
 the Rothamsted experiments ; he gave useful 
 information on the composition and nutritive 
 properties of Swedes, and in the feeding of sheep 
 with different artificial foods ; he also performed 
 experiments with phosphates, but either from 
 acting with phosphates in too rough a state 
 of division, or from failing to provide other 
 materials necessary to plants, or acting in un- 
 suitable soil, he arrived at the erroneous con- 
 clusion that insoluble phosphates have no 
 effect on plants, of which doctrine he was indeed 
 the most prominent advocate, but it is one which 
 is now universally rejected. His son. Dr. J. A. 
 Voelcker, succeeded in the direction of the ex- 
 perimente at Woburn, and added a series of 
 experiments in pots in which salts of Lithium 
 and Manganese were used, with the general result 
 of finding that they had either no effect, or a 
 retarding effect on plants, excepting the oxide, 
 which occasionally appeared to be beneficial. 
 More or less connected with those societies there 
 have been several private workers whose results 
 appeared, such as Mr. John Milne, Mains of 
 Laithers, Aberdeenshire, who in a methodical 
 and continuous way has carefully tested several 
 subjects bearing directly on practice. He has, for 
 
24 
 
 instance, found that dry and green fodder from 
 many sourcea, but representing equal proportions 
 of dry matter suitably balanced, have the same 
 nourishing value ; and that the increase in weight 
 in feeding cattle is proportionate to the age of 
 the animal — the younger the animal the greater 
 the amount of assimilation. So also Mr. David 
 Wilson, junr., Carbeth, has given much valuable 
 information on the comparative produce and 
 nutritive value of the grasses and clovers, based 
 on numerous exhaustive analysis. Generally his 
 results went to confirm the value of the grass 
 which is most esteemed, in Scotland at least, viz. 
 rye grass (which, on slender grounds, had been 
 deprecated by an English writer, Mr. Faunce de 
 Laune), and to distinguish cocksfoot (Dactylis 
 Olomerata) as the most productive grass, though 
 somewhat lower in nourishing value than the 
 other grasses generally cultivated. 
 
 Touching on Science as these Societies do, it 
 has been necessary to refer to their work, but it 
 will be seen that it follows from their object and 
 constitution that they have done nothing to 
 advance Science in a foundational way. 
 
VI. 
 ITURTHER FOUNDATIONAL WORK. 
 
 Rettjbnino now to Science proper, important 
 contributions were made to it in 1840 to 1850 by 
 Professor Thomas Way, who proved that soil had 
 the property of absorbing the minerals essential 
 to plants, especially potash, ammonia, lime, 
 magnesia, and phosphate, and of allowing useless 
 minerals or acids to pass away in the drainage, 
 thus bringing out a very beneficent and valu- 
 able provision of Nature, and.a fact of important 
 guidance in practice. In connection with this 
 discovery, it is a significant fact that nitrates are 
 allowed to pass ofi freely into the drainage, thus 
 suggesting that there is an abundant supply of 
 nitrogen at the command of the plants in the air. 
 This important jirovision of Nature for the 
 absorption of useful minerals has been con- 
 firmed by several continental Scientists. 
 
 Way also suggested that the means by which 
 this absorption took place was dependent on 
 the action of the Silicates of Alumina in the 
 soil, i.e., their union with the useful basic ele- 
 ments, and the consequent formation of double 
 silicates which are more or less easily decomposed, 
 and thus placed at the service of plants. But 
 although this opinion is generally taught, it 
 cannot be regarded as absolutely proved. That 
 Alumina acts in soil seems probable from the 
 fact that it is invariably present, and in large 
 quantity, thus suggesting that it performs 
 some purpose. No doubt, however, the same 
 might be said of Iron Oxide, and recent experi- 
 ments seem to indicate that its function is to 
 retard the growth of lowly forms of plant life 
 that prey on higher plants, for its presence in 
 water culture solutions has the efEeot of prevent- 
 ing Algae growth. 
 
 In 1857 Sir Charles Cameron found that 
 plants could make use of Urea, and this has 
 been confirmed by Mampe, WolfE, and Wagner. 
 
 If now we summarise what has been done in 
 Sritain up till 1850, in building up Agricultural 
 85 
 
26 
 
 Science, limiting reference only to outstanding 
 discoveries that helped to lay the foundations 
 of the Science, and excluding reference to mere 
 developments, elucidations, or applications of 
 these mscoveries, it is found to be little in extent, 
 yet important so far as it goes. 
 
 Prior to 1774. — ^Little or nothing. 
 
 1774. — Discovery of Oxygen — The most general 
 active element in Nature, and especially potent 
 in the formation of vegetable and animal matter 
 and the maintenance of life. By Joseph Priestley. 
 
 1774 to lSOO.—J)iscovery of (a) Carbonic Acid; 
 (6) of its presence in air ; (c) of its decomposition 
 under sunlight by plants ; (d) of the assimilation 
 of its carbon by plants ; and (e) of the liberation 
 of its oxygen to air for inspiration by animals. 
 By Percival, Priestley, and Ingenhouze chiefly, 
 but partly also by Black, Hales, and Cavendish 
 in Britain ; completed by the Swiss Scientists, 
 Bonnet and Senebier. 
 
 1800 to 1850.— Little or nothing. 
 
 1850. — Absorptive power of soil for mineral basis 
 essential to plants, potash, ammonia, lime, and 
 magnesia, as well as phosphate, and liberation 
 to drains of nitric, sulphuric, and hydro- 
 chloric acids. By Thomas Way. 
 
 It should be noticed that during the period 
 1800 to 1850, when little or nothing foundational 
 was done in Britain, a signal advance was made 
 in France by De Saussure by the discovery that, 
 insignificant as is the proportion of mineral 
 matter in plants, yet the provision of certain 
 minerals is absolutely essential to their growth. 
 This began what has constituted the major 
 work of agricultural Scientists for half a century, 
 and which cannot be said to be yet finally com- 
 pleted, viz.the definition of the minerals necessary 
 for plants, and the best forms and quantities 
 for the different crops, in other words, the Science 
 of Manuring. Nature, by means of air, water, 
 and heat, provides almost everything necessary 
 for the production of plant matter, and by means 
 of the minerals originally in soil she also 
 provides the needs of natural or wild plants, 
 but where man comes in to cultivate, in other 
 words, to act so as to produce more than the 
 natural growth, she leaves to him to find out, and 
 apply the most suitable minerals to secure such 
 
27 
 
 larger produce. It is a slight call, but even 
 yet it is far frpm being completely understood, 
 and still farther from being properly attended 
 to, even to the extent that it is understood. By 
 doing so, it is safe to say that the produce of 
 Britain could easily and economically be doubled. 
 
 BETEOSPEOT. 
 
 In the preceding chapters the ■progress of Agri- 
 cultural Science in Britain has been traced, limit- 
 ing reference to those results that constituted, 
 or led to, reliable steps forward, and more or less 
 ignoring the labours of workers who, however 
 earnest their work, had not the fortune to un- 
 cover any foundational ground. It is a record of 
 work, of steps in advance, and not of workers, 
 which would not only have gone beyond the 
 limits of available space, but might have given 
 rise to confusion. 
 
 The record commenced with the earUest efforts 
 in this country — when they were little else than 
 aspirations and fruitless gropings — and were 
 continued up to, and included, the work at 
 Rothamsted. Up to that time only four names 
 stand out conspicuously, viz. Priestley, Liebeg, 
 Johnston, and Way. Joseph Priestley of London, 
 by his discovery of oxygen, not only laid the 
 foundation of agricultural science but of chemical 
 science, as oxygen is the general actor everywhere 
 in Nature, and without a knowledge of it, all was 
 chaos. Liebig stands out not so much by any 
 foundational fact discovered (for his suggestion 
 which led to the huge manufacture of super- 
 phosphate can hardly D6 regarded as an advance 
 in science in the sense here observed) as in his 
 forceful and lucid exposition of agricultural 
 science up to his time, which cleared away the 
 stagnation blocking any real progress. Johnston 
 was the first to set forth the facts then known 
 in methodical scientific form strengthening the 
 structure, and filling up gaps by scientifically 
 proved data, and presenting, for the first time, a 
 scientific basis of agricultural science ; while Way 
 stands out by finding the retention by soil of the 
 minerals essential to plants, and the riddance of 
 the non-essential or abundant minerals. He did 
 much other work which does not find a place here, 
 as the results have not proved to be reliably 
 acceptable, and hence do not form progressive 
 steps — such as the double-silicate theory already 
 explained — and his idea that soils absorbed and 
 fixed nitrogen, which has been clearly refuted 
 by continental investigators. Unfortunately for 
 
28 
 
 British prestige, although Priestley commenced 
 the study of carbonic acid, he had not the 
 fortune to bring the investigation to completion, 
 and it fell to foreigners both to find out its real 
 nature and its action on plants. The existence 
 and r61e of carbonic acid, along with Priestley's 
 discovery of oxygen, really formed the true key 
 to plant production. Formerly the soil was 
 credited with plant production, and all kinds of 
 " mysteries " were associated with its action ; but 
 now the truth shone out, viz. plants are mainly 
 formed from water (given through the soil) from 
 carbonic acid and nitrogen (through the air — the 
 nitrogen being erroneously supposed at that time 
 to be available only in the compound forms of 
 ammonia and nitric acid). " Humua," the sup- 
 posed mysterious actor in the soil, was found 
 by continental scientists to be no actor in the 
 feeding of plants, and the soil was found to be 
 merely the provider .of water and of a minute 
 quantity of mineral matter. The ancient error 
 that plants are derived from soil was thus eradi- 
 cated. Thus, at last the foundation of agri- 
 cultural science was outlined clearly and forcibly 
 in Britain by Liebig's first publication in 1842, 
 and put in form by Johnston in 1845. For Liebig 
 not only drove out the " humus " ideas but he 
 elucidated the necessity of attention to the minute 
 quantity of certain minerals as the real factor in 
 practice to secure large production. His analyses 
 of plants showed that the quantity of mineral 
 matter in plants is minute, and hence very small 
 in a good crop over an acre ; his analyses of soils 
 showed that the quantity of these minerals in an 
 acre of soil is very great, and yet that a very small 
 quantity of certain minerals given as manure 
 greatly increased production ; he formed the ob- 
 vious conclusion that the large quantity in soil, 
 locked up in its dense crystalline form, was very 
 gradually set free (by weathering, i.e. by frost, 
 oxygen, &o. ) from their inert state into an active 
 state, or a state available for plants ; that what an 
 acre can grow is regulated largely by what is thus 
 made available, and that as this is too small to 
 give the large production required in cultivation, 
 the essential minerals in the soil must be added to 
 in the form of manure. Thus, not only were the 
 foundations of agricultural science laid, but the 
 intelligent application in practice was elucidated. 
 This well substantiated doctrine set agoing 
 several workers, but it cannot be said that the 
 work for a, long time was progressive of agri- 
 QUlturaJ science, Daubeny in England, for 
 
29 
 
 instance, formed (in 1845) the idea that the matter 
 available in soil was such quantity as was soluble 
 in carbonic acid, assuming that this acid was made 
 use of by the plants to get the minerals into 
 soluble form. Not only, however, is it now 
 accepted that carbonic acid does not show the 
 degree of availability, but the assumption that 
 plants make use of carbonic acid to acquire their 
 mineral food has not been verified. So also 
 Daubeny held that plants did not excrete; but 
 although that idea has been too generally taught 
 considering the meagre grounds it rested upon, 
 and the probably stronger grounds against it even 
 at that time, modern inquiry, both here and 
 abroad, indicates that Daubeny worked in this 
 subject also on misleading lines, and hence he 
 made no progressive foundational step in agri- 
 cultural science. 
 
 It was at this well-advanced stage that the Roth-, 
 amsted trials were started — a year after liebig'a 
 rousing action. That is to say, at the stage when 
 the mineral food of plants had come strongly to 
 the front, but before it was defined what partic- 
 ular minerals were essential. Lawes started his 
 trials in 1843 to elucidate this point, by " com- 
 plete" and"partial" manuring but,unfortunately, 
 as has been mentioned, in a haphazard unscientific 
 way. It really seems doubtful if Lawes ever got 
 the " humus " idea and the " mysteries " of the 
 soil out of his head, and whether, presuming to 
 combat Liebig's view that nitrogen was provided 
 by air (as ammonia erroneously), the bitter 
 conflict did not make him obstinately adhere 
 to the " soil mysteries," for they still appear to 
 dominate at Bothamsted, while his crude trials 
 so strongly denounced by laebig are still con- 
 tinued on the same faulty plan and form the basis 
 of nearly all the conclusions. 
 
VII# 
 
 WORK AT ROTHAMSTED. 
 
 An enormous amount of agricultural investiga- 
 tion has been carried out at Rothamsted (in Herts, 
 England) during the past sixty years. From 
 the lengthened period during which the trials have 
 been carried on, from their extent, and from the 
 money that has been spent on them by a private 
 individual, they have attained a notoriety second 
 perhaps to those of no other organisation for 
 agriciutural inquiry. The distinctive feature 
 of the work is — that the same crops have been 
 grown, and the name manures have been used, in 
 the same soil, year after year, for more than half 
 a century. The manuring has been very peculiar, 
 very heavy, and very costly ; the crops have not 
 been over the average, and usually far under the 
 average crops usually grown. Hence the ques- 
 tion at once arises — what object is sought to be 
 gained by this practice ? It is not the usual 
 practice ; it is not recommended by the experi- 
 menters to be practised ; it never can from its 
 nature be adopted in practice ; nor would con- 
 clusions drawn from so peculiar conditions be 
 applicable to practice. Direct benefit to practice 
 must therefore be put aside — the experimenters 
 practically admit it. 
 
 But in this " history " itis intended only to record 
 any progress that has bee i made in agricultural 
 science. In this connection the remarkable 
 statement has lamentably to be made that while 
 certain separate branches of the work at Rotham- 
 sted have given much useful information, yet, 
 from the distinctive large scale trials by which 
 Rothamsted is identified, and on which so much 
 labour, money, and time have been spent — no 
 foundational advance step in agricultural 
 eeiencc has been made. So remarkable a result 
 calls for going out of the way to explain the 
 nature of this work. It might be passed over, 
 but Rothamsted work looms so largely in popular 
 recognition that it cannot be thus summarily 
 30 
 
31 
 
 dismissed. Yet when we gauge that recognition 
 what does it consist in ? To the great mass of 
 agriculturists the Rothamsted work is unknown, 
 or known merely as a name ; to the smaller 
 number who have applied their minds to it in the 
 hope of deriving useful information, it presents 
 a, maze from which they can extricate little or 
 nothing to assist them ; while to the compara- 
 tively few agriculturists possessed of some 
 scientific knowledge, and also to scientists who 
 have made a careful and impartial study of the 
 work, it presents features that cause many of 
 them silently to ignore the larger part of the 
 work. 
 
 Let us now see what this is owing to. In the 
 first place, Mr. J. B. Lawes — ^the originator of 
 the trials — was not a scientist — ^he never pre- 
 tended to be so — ^he was essentially a commercial 
 man owning a farm, possessing some little 
 knowledge of chemistry, and having a beUef in 
 its successful application to agriculture. He 
 framed experiments on a large scale in 1843, 
 which were unavoidably crude at this early 
 period, and with his limited knowledge. Taking 
 advantage- of Liebig's discovery of rendering 
 phosphate soluble by sulphuric acid, he built 
 up a large trade, and applied much of the wealth 
 thus accumulated to continuing, and unfortun- 
 ately insisting on the continuance of the experi- 
 ments he had crudely framed, while adding others 
 as time went on. In a vague way he hoped that 
 some information would be got by doing on the 
 large scale what has been done frequently, and 
 properly, on the small scale, viz. giving to 
 certain plots all the materials supposed to be 
 required by plants, and to othar plots only certain 
 of these materials, in order to find what was 
 essential, and what was the action. Although 
 such complete and partial manure tests cannot 
 properly be made on the large scale, yet it might 
 be interesting and useful to find the efiects on 
 large areas. Unfortunately, however, at the 
 time the Eothamsted trials were begun, com- 
 paratively little was known regarding the mineral 
 food of plants, or the requirements of the various 
 crops ; hence serious errors were made regarding 
 both the forms and the quantities of ingredients 
 used, and, most unfortunately, these forms and 
 quantities have been continued yearly till the 
 
 g resent time, resulting in injured soil and un- 
 ealthy plants. It is this feature that mars the 
 usefulness of these experiments as guides both 
 for ordinary farm practice, or for scientific 
 
32 
 
 information regarding healthy plants grown in 
 healthy soil. 
 
 One illustration may suffice to show that 
 these large field trials were framed on a system 
 such as no one trained in science in its bearings 
 on agriculture would then have adopted, such as 
 no one certainly would now adopt, and such as 
 no farmer would think of using in practice. It is 
 this : — In most of the plots 100 lbs. Glaubers 
 salt (sulphate of soda), 200 lbs. sulphate of 
 potash, and 392 lbs. of superphosphate were 
 used, making a total every year of 792 lbs. per 
 acre of a mixture which was mostly soluble in 
 water, and which included about 400 lbs. of 
 combined sulphuric acid. It strikes one as 
 unfortunate that such a mixture should have 
 been used at all, but one is struck with amaze- 
 ment that this large quantity of so peouUar a 
 kind of manure should have been applied to the 
 same land, year after year, for over sixty years ; 
 it represents nearly 18 tons per acre, and that 
 in the form of soluble alkaline salts. Even to 
 this were usually added heavy doses of saline 
 nitrogenous manures, viz. 200, 400, or 600 lbs. 
 ammonia salts, so that each of tliese acres has 
 had from 9 to 11 J cwt. soluble salts applied 
 to them, year after year, since 1843. Reckoning 
 only sixty years, the plots completely manured 
 have actually received from 26 to 37 tons of 
 alkaline salts ! The soil is thus in the peculiar 
 state that may briefly be called drugged, and the 
 natural effects of being thus dosed to excess is 
 evident in both the soils and the plants. This is 
 plainly brought out.not only by personal examina- 
 tion of the growing plants on the farm, and by 
 the results given in the reports, but is also 
 borne out by the statements of the experimenters 
 themselves (which are given further on). It 
 seems obvious that conclusions from such trials 
 can apply only to plants grown under such 
 exceptional conditions and to soils thus excep- 
 tionally dealt with. 
 
 On commencing (as the writer did many years 
 ago) a serious study of the Kothamsted experi- 
 ments, one is staggered by the feature of the large 
 quantity and pecuUar character of the manures, 
 and grave doubt is felt, from the outset, how far 
 one need seriously consider results and conclu- 
 sions made from trials based on such a plan. 
 Giving expression to this feeUng on the occasion 
 of a visit of Rothamsted by the writer, when he 
 was guided over the plots by Mr. Lawes (he was 
 not then knighted), Mr. Lawes seemed disinclined 
 
3S 
 
 to pursue the subject, and it was not pressed. 
 On a later visit, however, being aooompanied by 
 Dr. Gilbert, it was again expressed, but rather 
 evaded. As chemist to chemist now, however, 
 the writer pressed it, when Dr. Gilbert frankly 
 admitted that the trials were designed (before 
 his time) " without rhyme or reason " ; he had 
 to continue them as a duty, adding, as by way of 
 excuse, that being begun on a certain line it 
 was desirable to maintain the continuity." One 
 may reasonably demur to acquiescing in this view. 
 If the plan was bad, the sooner it was departed 
 from the better ; if, the bases were unsound or 
 unsatisfactory, the conclusions are likely to be 
 even mischievous, should they be represented as 
 having a bearing on the science or the practice of 
 plants grown under natural conditions. 
 
 But even if the conditions had not been faulty, 
 there seems no justification for the long con- 
 tinuance of the trials. No scientist has con- 
 sidered it of any use to continue even the properly 
 framed " complete " and " partial " trials 
 beyond a few years in the same soil. That it has 
 been continued so long at Kothamsted, faulty 
 as it was, can be explained only by a desire to 
 show what could not be shown elsewhere; but 
 much the same might be said of a dozen babes 
 fed on different kinds of physic, for the excessive 
 quantities, and incomplete and injurious kinds of 
 manures given continuously, constitute similar 
 abnormal conditions. Under these circumstances 
 we can hardly expect any progress in science to 
 follow from these trials, constantly quoted 
 though they are. 
 
 Later on, however, Lawes called in the aid of 
 able scientists — Gilbert, Pugh, and Warington — 
 who, while unfortunately largely engaged on the 
 field trials, which formed the insignia of the place, 
 yet carried out other work and provided no 
 Uttle useful information. Obviously the value 
 of the work depends on the degree of its utility 
 to agricultural science, or to agricultural 
 practice. It is therefore desirable to separate 
 the useful from the comparatively useless, and 
 to present, in short and simple form, what may 
 reaUy be learned, and what benefit may be 
 derived, from the Rothamsted work. To do this 
 clearly, and to do justice both to the Rothamsted 
 work and workers, as well as to the readers, it 
 seems necessary to arrange the results in some- 
 thing like an order of merit. 
 
 In the great labyrinth of figures, tables, and 
 statements covering the numerous reports, and 
 
 4 
 
34 
 
 other writings over sixty years, this is no easy 
 matter, and the difficulty ia greatly increased by 
 the necessary scrutiny of the conclusions that 
 have been formed, and of the foundations on 
 which these conclusions are supposed to be based. 
 The writer prepared long ago, at great trouble, a 
 detailed impartial account, but it has not yet been 
 published, and space cannot be used here for it. 
 A shorter treatment must suffice here, but some 
 assurance of its accuracy is given by the fact that 
 the whole matter has been closely studied in 
 detail. 
 
 Recently the newly appointed director at 
 Rothamsted — Mr. A. D. Hall — ^has issued a 
 "Summary" of the whole work, which renders 
 it possible to deal with that work more easily 
 than with the numerous annual reports. It will 
 be referred to in the following pages as " The 
 Summary." 
 
 Several accounts of the Rothamsted work have 
 been written by others, but none of them have 
 been in the nature of impartial judgment. 
 They have all, so far as have been seen, been 
 merely descriptive and courteously laudatory ; 
 and, while expressions of grave doubt in regard 
 to them are very frequent oy agriculturists, and 
 especially by those more or less famiUar with 
 agricultural science, yet no one seems to have 
 ventured to deal seriously with the work in the 
 form of impartial examination. 
 
 It does not seem right, in the interest of 
 agricultural science, that such timidity should 
 exist in a matter of this kind — ^it is to mislead 
 both the uninitiated and the student who fre- 
 quently becomes a teacher ; it perpetuates 
 error, and the historian incurs a serious responsi- 
 bility who screens misleading matter. Reluct- 
 ance to show error prevents many from speaking 
 plainly. It has prevented the writer for many 
 years, though repeatedly urged to do so ; but now 
 when he has undertaken to write a " history of the 
 progress of agricultural science," they stand right 
 in tne way, and he has no escape from describing 
 the trials. In doing so, it would be culpable to 
 give a tacit acquiescence to error, especially as it 
 is still going on, and still being referred to as 
 laudable and reliable. 
 
 To this timidity there is one notable exception, 
 viz. that of Liebig, who spoke in unmeasured 
 terms, and it is regrettable that his censure did 
 not at once cause a diversion at Rothamsted from 
 the line originally fixed. Thus, in his Natural 
 Laws of Huahandry (page 157), he observes, 
 
35 
 
 " The many unsuccessful experiments of Lawes 
 and Gilbert to make a clover-siok field again 
 productive for clover leads to nothing. If I have 
 to bestow on these experiments an attention 
 which they do not deserve, my object is, not to 
 submit them to a parsing criticism, but to warn 
 the practical man how he should not proceed 
 in trying to solve his problems, if he wishes that 
 his efforts should meet with suoeess." Again 
 (page 298), " The experiments of Lawes and 
 Gilbert are very far indeed from proving the 
 conclusions that they wish to draw ; they 
 establish rather the fact that these gentlemen 
 have not the sUghtest notion of what is meant by 
 argument or proof." So also (page 300), " These 
 experiments are worth notice in the history of 
 agriculture, because they show what statements 
 could be laid before farmers at a time when 
 ignorance of first principles did not yet permit 
 scientific criticism." Apart from personal feel- 
 ings of duty, these words by one of the most 
 eminent men in the history of agricultural science, 
 give justification for unreserved treatment. 
 
 If now an attempt be made to place the 
 subjects treated at Bothamsted in something 
 like an order of merit, with the object both of 
 defining the degree of utihty and of indicating — 
 which is the special object of this history — 
 any progress made in agricultural science, it 
 appears obvious, under the circumstances already 
 mentioned, that the large field trials at Rotham- 
 sted, by which Rothamsted is specially identified, 
 must, without any hesitation, be assigned to a 
 subordinate place. 
 
 Not many years ago one would have been 
 disposed to have placed in first rank, in view of 
 its supposed scientific value, the most careful 
 experiments made at Rothamsted to test the 
 accuracy of Boussingault's conclusion that plants 
 do not utiUse the rcee nitrogen of air, for the 
 results went far to settle the views on that 
 subject for nearly half a century. Unfortunately, 
 however, for Rothamsted, this set of experiments 
 has received three heavy blows that, in combina- 
 tion, have been fatal to the conclusion made. 
 !First came the proof from Atwater in America, 
 and from Hellriegel in Germany, that legumes, at 
 least, actually do absorb ni&ogen; Helkiegel 
 adding that they did so by means of bacteria in 
 the root nodules. As " The Summary " admits 
 
36 
 
 this proof " came as somewhat of a disappoint- 
 ment to the Rothamsted investigators." It led 
 to further experiments being made at Botham- 
 sted, when the mistake had to be admitted ; 
 and the bacterial explanation was unfortunately 
 adopted, as the explanation jf what was regarded 
 as an exceptional power applying only to legumes ; 
 the doctrine of non-absorption of nitrogen 
 being still held to apply to all other plants. The 
 bacterial explanation, however, was in course 
 of time also undermined, and this constituted 
 a second blow to Bothamsted. It came from 
 Germany in the form of proof by fProfessor 
 Pranck of Berlin that the increase of nitrogen in 
 legumes is obtained even when they are grown in 
 sterilised soil, and on plants on which no nodules 
 were formed, and where therefore bacteria were 
 absent, and this has been confirmed by PfeifEer 
 and Ehrenberg. Dr. Bemy of Breslau, and 
 Dr. Thiele of Berlin — who formerly favoured the 
 bacterial idea — have themselves demolished it. 
 This evidence indicates that a direct, though 
 unknown method for absorption of nitrogen 
 must exist in legumes at any rate, and probably 
 therefore in all other plants. There comes now 
 from Scotland the evidence that all green plants 
 are possessed of special organs on or about their 
 youngest leaves, by which they direcUy absorb 
 and fix the nitrogen of air in difierent degrees. 
 This doctrine, which emanates from the writer, 
 harmonises with the conjecture that was made 
 by Franck in Germany after thoroughly investi- 
 gating the whole subject ; also with the views of 
 the eminent botanists, Sachs and Van Tieghem ; 
 it conforms also to the experience of practice, and 
 the general observation of large scale growth in 
 nature ; and it dissipates the contradictions that 
 were constantly arising under the former con- 
 ceptions. Evidently, therefore, that part of the 
 Bothamsted work which applies to the fixation of 
 nitrogen has, from the point of view of utility or 
 progress of science, also to be ranked in a sub- 
 ordinate position. Here it may merely be 
 mentioned that the cause of the failure of the 
 Bothamisted trials (as of Boussingault's trials) 
 on the fixation of nitrogen was the growth of the 
 trial plants under restricted unnatural conditions, 
 which resulted in the growth of only very smaU, 
 very feeble, diseased, and undeveloped plants, 
 altogether unfit to display the ability of plants in 
 a TuUural and vigorous state. 
 
 With these preliminary observations, which 
 are made chiefly to explain how, what is generally 
 
37 
 
 regarded aa the more conspicuous work at 
 Rothamsted, must give place in priority or 
 merit to some of the other work, it may be 
 useful now to present a table of that work, 
 in which an attempt is made to roughly indicate 
 the degree of usefulness. 
 
 MOST irSEFUI. RESULTS AT ROTHAMSTED. 
 
 1. Contribution to the processes of nitrifica- 
 tion and denitrification. These actions were 
 discovered by Muntz and Schloesing in France, 
 but they were verified and much developed by 
 Warington at Rothamsted. 
 
 2. The determination of the amount of 
 ammonia and nitric acid in air. 
 
 3. The determination of the losses and gains 
 of nitrogen (also of chlorine and sulphuric acid) 
 by the analysis of drainage waters. 
 
 4. Confirmation — by the analysis of soils at 
 different depths — of what was discovered by Way, 
 viz. the conservation of phosphate and potash by 
 soil, and the Uberation of nitrogen as nitrates. 
 
 5. Evidence of direct absorption by plants of 
 nitrogen in air. This is certainly not a doctrine 
 given out by Rothamsted — ^it is in fact directly 
 opposed to the dominant idea in their work — 
 buji the evidence is given by the actual Rotham- 
 sted results as given in the reports. 
 
 6. Cattle-feeding experiments and action of 
 food in the animal body. 
 
 SUBORDDTATB RESTTLTS. 
 
 1. Contribution to the effect of partial and 
 complete manuring, which was ascertained by 
 water culture and small scale trials in Germany 
 and elsewhere. It was sought to be demonstrated 
 at Rothamsted by large trials, extending over 
 sixty years, which, however, are practically 
 valueless owing to the peculiar plan of manuring 
 adopted at the outset, and adhered to throughout. 
 
 2. Botanical composition of grasses and 
 legumes on differently manured soils. 
 
 3. Sotanical composition of field pasture. 
 
 MINOR RESULTS. 
 
 1. Rainfall at Rothamsted. 
 
 2. Percolation of rainfall throughout soil, but 
 soil not in natural condition. 
 
 3. Feeding value of melted barley. 
 
 4. Experiments on ensilage. 
 
 g. Composition of ^heat crop, 
 
38 
 
 Having thua cleared the way by Beparating the 
 useful from the nselesa, or minor, reference 
 should now be made, in some detail, to each of 
 these investigations at Bothamsted, in order to 
 select what forms any real advance in agricul- 
 tural science. 
 
39 
 
 (a) Most useful Results at Rothamsted. 
 
 NITBIPI CATION. 
 
 Schloesing and Muntz, in France, discovered 
 the process of nitrification {i.e. oxidation of 
 nitrogenous matter and formation of nitrates), 
 proved that it was caused by bacteria, and that 
 oxygen and water were necessary, as well as a 
 certain temperature, varying from 12° C. to 
 35° C. At Rothamsted, Warington verified the 
 process of nitrification ; he confirmed that the 
 action was bacterial, by showing that it was 
 checked by an antiseptic, and that in a sterilised 
 soil, seeding with soil, or a bacterial solution, was 
 necessary before the action took place ; and he 
 also showed that darkness, and the presence of 
 phosphoric acid, were necessary. Further, he 
 demonstrated that the action goes on chiefly in 
 the upper nine inches of soil, it being charged 
 with oxygen ; and finally, that the change is not 
 direct to nitrates, but first to nitrites, and that 
 the two actions are performed by two different 
 kinds of bacteria, of which he succeeded in form- 
 ing separate cultures. Warington also developed 
 the subject by finding that the organisms capable 
 of carrying on the process were numerous ; he 
 found no less than 37 organisms, varying in their 
 ability to act as nitrates only, or nitrites only. 
 Hunro made the important contribution that 
 nitrification by bacteria could take place from 
 mineral matter, i.e. from carbonate of lime 
 and carbonate of ammonia derived from purely 
 inorganic sources, and this was confirmed by 
 Winogradsky. 
 
 De-nitrification {i.e withdrawal of oxygen from 
 nitrates) goes on in soil where oxygen is deficient, 
 and markedly so, as found by Warington, where 
 soil has become waterlogged or saturated, 
 nitrogen gas being evolved. 
 
 It may be seen from the above outline that 
 the Rothamsted contribution — by Warington's 
 labours — to the subject of the changes undergone 
 by the nitrogen compounds in the soil is very 
 important. Although largely confirmatory, yet 
 confirmation 13 essential, and his develop- 
 ments went far to make the important subject 
 of nitrification complete. It renders clear one 
 link in the chain of the great cycle of nitrogen in 
 nature. 
 
40 
 
 AMMONIA AND NITBIO ACID IN AIB. 
 
 The estimation of the ammonia and nitric 
 acid in the rainfall ia also one of the more useful 
 facts brought out at Rothamsted. (Sulphuric acid 
 and chlorine were also estimated, but these de- 
 terminations are of little practical value, as they 
 refer to substances not essential to plants — or 
 only doubtfully so, and, in any case, in minute 
 quantity.) It was found that about 4 lb. is the 
 total quantity of nitrogen that falls yearly per 
 acre in the average rainfall, and this is approxi- 
 mately the quantity found by continental 
 chemists (somewhat higher), and it ia definitely 
 confirmed by the very numerous determinations 
 made at Rothamsted over a prolonged period. 
 They bring out the average amoimt as 3'97 lb; 
 nitrogen per acre per annum (of which 2'782 
 is ammonia and 1'189 is nitric acid). There 
 is, however, a trace of combined nitrogen present 
 in air in the form of organic dust, &c., and 
 this has been roughly computed at about one- 
 third of the combined ammonia and nitric acid, 
 thus bringing the total to not more than 5 lb. 
 per acre. If we take the continental results, 
 it would be nearer 4 lb. per acre. 
 
 This is an important and useful fact — one 
 which is obtainable only by laborious careful 
 trials — and, confirmed as the result is by so 
 numerous tests at Rothamsted, viz. monthly for 
 twenty years (apart from the earlier trials), and 
 verified as the tests have been by Professor Way 
 and Professor Frankland, confidence may be felt in 
 the accuracy of the estimation. One feels, how- 
 ever, that the very prolonged tests — monthly for 
 twenty years — is largely wasted time and labour ; 
 still, that does not detract from the result itself. 
 
 LOSSES AND GAINS Or NITROGEN, ETC., 
 BY DRAINAGE 
 
 The broad facts demonstrated by the investi- 
 gations at Rothamsted on this subject are : That 
 ammonia salts are speedily changed to nitrate 
 (and nitrite) in the soil, and that the nitrate 
 thus formed, as well as nitrates appUed to manure, 
 are speedily washed down into the drains and 
 constitute one of the main losses of nitrogen. 
 
 The nitrifying process on ammonia salts and 
 on nitrogenous organic matter, it was found, takes 
 place perhaps constantly, but chiefly in the warm 
 period of the year, and the nitrates are carried away 
 to the drains chiefly by the heavy autumnc^ an^jl 
 
41 
 
 winter rains. Hence, broadly speaking, the gain 
 ia in summer, i.e. the growing period, and the 
 loss is in autumn, i.e. when growth ia checked. 
 The loss was found to vary according to the 
 soil : if the texture is good, capillary action 
 brings up much of the nitrate for use ; but if the 
 soil is dense, as at Bothamsted, capillarity is 
 said to be checked (though it is doubtful if 
 density would do so), and hence the figures given, 
 for such soil, would not hold good for soil in a 
 different state. 
 
 The quantities of nitrate that pass through 
 the soil have also been estimated monthly for 
 twenty-six years in bare soil. As, however, this 
 soil bears no crop, its results do not apply to 
 what would take ]^ace in cropped soil in ordinary 
 cultivation, but they serve to show the general 
 principle. The quantity washed out in this 
 bare unmanured soil appears to be from 1 to 
 6 lb. nitrogen monthly, or to about 36 lb. 
 nitrogen per acre per annum; while in cropped 
 soil the quantity varies, according to the 
 manure given, from 21 lb. to 56 lb. per 
 acre. If the average of 34 lb. is taken, 
 and, say, 40 lb. is allowed as carried ofi 
 in crop, this means an annual loss sustained 
 by the soil of no less than 74 lb, nitrogen. 
 The gain from ammonia in air being only 4 or 
 5 lb. there would thus be a net annual loss 
 to the soil of 70 lb. This indicates a very 
 large deprivation of its nitrogen annually. 
 
 These being the facts, it is somewhat remark- 
 able that the obvious chief conclusions have been 
 ignored, or, at least, not brought out prominently, 
 viz. : first, that while nature carefully conserves 
 in the soil two of the three substances chiefly 
 essential to plants — phosphate and potash — 
 she freely allows the third one — ^nitrogen — to 
 escape to the drainage system in the form of 
 nitrates, thus indicating that she has an avail- 
 able supply elsewhere ; second, that by this great 
 annual loss by the soil of about 70 Ibi nitrogen 
 per acre (equal to 2^ cwt. sulphate of ammonia) 
 the power of growth would be checked were there 
 not a large compensating gainj third, that the 
 minute gain of 5 lb. from compounds in air 
 scarcely affects the situation, as the crops contain 
 eight or ten times as much, and that,' conse- 
 quently, we are driven to discern that the vast 
 quaiitity of nitrogen in air piuat annually fee 
 
42 
 
 drawn upon to make up the deficiency — and 
 this has now been proved to be the case. 
 
 It thus becomes apparent that results at 
 Rothamsted itself (and these are not the only 
 ones) disprove the dominant idea at Bothamsted 
 that plants derive nitrogen only from the soil by 
 the roots, and that they are unable to fix nitrogen 
 directly from the air. 
 
 These facts ascertained at Bothamsted, of the 
 losses and certain of the gains of nitrogen, are 
 well to know, but such estimations being made 
 monthly for a few years should amply suffice 
 to give all that can be useful ; here, again, it seems 
 a great waste of time to have continued these 
 monthly estimations, as has been done, for twenty - 
 six years. 
 
 COJSrSEKVATION OF POTASSIUM AND POTASH IN SOIL 
 AND LIBERATION OF LIME AND SULPHUEIO ACID. 
 
 Five analyses of drainage waters were made ; 
 they were fairly complete, except as to chlorine, 
 which is immaterial. They confirm what has fre- 
 quently been shown by other experimenters — and 
 first by Professor Way — that the valuable 
 mineral substances, phosphate and potash, are 
 carefully conserved by the soil, while" nitrogen 
 is freely allowed to escape — never, however, as 
 ammonia (except in traces), but always as nitrates. 
 
 FREE NITBOGBN OF AIR AVAILABLE FOB PLANTS. 
 
 It may cause surprise to find the above heading 
 as applying to Bothamsted, because it is dia- 
 metrically opposed to the " dominant idea " 
 which runs through the whole of the Bothamsted 
 work. But the actual results of the trials at 
 Bothamsted that give evidence of fixation of 
 free nitrogen are numerous, although the experi- 
 menters sought, no doubt conscientiously, to 
 explain them by other causes. The difficulty 
 of thus explaining them, however, was often very 
 great, much perplexity being experienced, and 
 much ingenuity being exercised, to account for 
 the results under the infiuence of their dominant 
 idea that plants are not able to utilise the free 
 nitrogen of air. 
 
 Three explanations, or refuges, were sought at 
 Bothamsted when met by the constantly occur- 
 ring gains of nitrogen from an unknown source. 
 
 The usual explanation was, the " great re- 
 
43 
 
 serve " of nitrogen in the soil. How can a 
 reserve be a gain, or account for a gain ? This 
 " reserve " was a determinable and determined 
 quantity, and notwithstanding the losses by 
 nitrogen, being carried off in drains and crops, 
 the reserve continued practically the same, and 
 that even in cases where legumes did not enter — 
 as will be shown farther on. Any loss is ac- 
 counted for by the poorness of the crops and 
 the kind of the crops being svioh as not to give an 
 opportunity for more absorption by tnem of 
 nitrogen than was carried ofi as nitrates to the 
 drains. Besides, the much lowered crops of 
 cereals, when artificial forms of nitrogen were 
 withheld, proves that but little of, this reserve 
 is available, and that it could not be the main 
 source of the growing crop. Evidences, how- 
 ever, are frequent (to be referred to farther on), 
 in regard to which the somewhat vague explana- 
 tion of the " great reserve " cannot possibly 
 apply. 
 
 The second explanation was the action of 
 bacteria in the legume nodules. That this 
 explanation is a delusion has already been 
 shown. The fact is that the very existence of 
 bacteria in the active stage of these nodules has 
 never been proved. That they exist in the later 
 or decaying stage is both possible and probable, 
 as bacteria are everywhere, and abundant in 
 decaying matter. Another fact is that the 
 material of these nodules has never heen proved 
 to absorb nitrogen. A third fact is that legumes 
 have been grown without having nodules, and yet 
 a, gairt of nitrogen was found. Those who have 
 given out, or strongly upheld, this doctrine 
 have a good deal to answer for. Acting without 
 data they are really responsible for retarding 
 the progress of Agricultural Science. 
 
 The third explanation was the supposed 
 action of certain bacteria in soil which were 
 assumed to have the power of absorbing nitrogen 
 directly from air. This explanation was first 
 given timidly, as if somewhat ashamed of its 
 validity, and certainly having no proof of its 
 validity. Latterly, however, there has been a 
 tendency at Bothamsted to fall back on these 
 soil bacteria as the most likely refuge, and 
 " Azotobacter " and other bacteria in soil are 
 made much of. The recent investigations of 
 Pfeiffer and Ehrenberg, however, and especially 
 the later investigations by Remy, and finally 
 by Thiele, prove that no such action takes place. 
 ThJele, though believing in the doctriae, honestly 
 
44 
 
 recognised that there was no real evidence of it, 
 and, seeking to obtain real evidence of it, he, 
 after careful trials, frankly admits that no 
 evidence was found, and summarises his own 
 and former inquiries by saying, " there is no 
 proof at all that they (bacteria) absorb nitrogen, 
 rather the contrary — and we have merely btiilt 
 up theories of which there are no proofs." It 
 is really a curious idea — that of bacteria absorb- 
 ing nitrogen from air. It suggests their carry- 
 ing out a strange process, for the well-known 
 fact is — that bacteria are parasitic plants that 
 find all their food on living or dead organic 
 matter, which contains all they need, including 
 nitrogen. To say that certain of the colourless 
 parasitic bacteria are not parasitic for nitrogen, 
 and are parasitic for everything else, and hence 
 that they go to air to get their nitrogen, is — 
 to say the least — to ascribe to certain bacteria 
 a very exceptional position. They must actually 
 reject the nitrogenous matter in their food and 
 go to air for it. 
 
 A few instances may now be given of the 
 evidences provided by the Rothamsted experi- 
 ments that nitrogen of the air is directly fixed 
 by green plants. 
 
 From pages 10 of the " Summary " the fol- 
 lowing data are obtained : — 
 
 Lb. per acre. 
 Nitrogen in soil originally . . . . 2,657 
 
 Nitrogen in soil after three years . . 2,832 
 
 Gain in nitrogen of soil . . . . . . 175 
 
 Nitrogen in crops carried off . . . . 319 
 
 Gain of nitrogen from an unknown 
 source . . . . . . . . . . 494 
 
 Evidently there is here a large acquirement 
 of nitrogen from an unknown source, and that 
 not — be it observed — from a reserve, because the 
 total nitrogen in soil originally is estimated. 
 This gives a serious blow to the " soil reserve " 
 idea. The crops in this case, however, included 
 legumes (the second refuge), and for the benefit 
 of those who may still cUng to the nodule theory, 
 and hence may suppose that the presence of 
 legumes is the explanation of the gain in nitro- 
 gen, an instance may now be given into which 
 legumes do not eijter, but wbea^, and wfient 
 
45 
 
 We Ihave such an instance on page 8 of 
 the " Summary." In this case the quantity of 
 the nitrogen originally in the soil is strangely not 
 stated in the " Summary," and we are led — so 
 far as the Summary helps us — merely to infer 
 an admitted gain of nitrogen from the two 
 statements (1) that Boussingault found a gain 
 in wheat crops over the manure supplied, and a 
 large gain in legume crops, and (2) that " similar 
 evidence was accumulated at Rothamated, and 
 was made more cogent by the analysis of the 
 soils, which showed not only no decrease, but 
 an actVMl gain of nitrogen during the period 
 when the leguminous crop was producing such 
 large quantities of nitrogenous matter above- 
 ground." There is a confusing omission in that 
 sentence, because not only were the leguminous 
 crops, but, of course, the cereal crops also were 
 producing "nitrogenous matter above ground." 
 Although the usual quantity of nitrogen origin- 
 ally in the soil is not stated in the " Summary," 
 it was given in Nature of 26th April 1906, 
 in'an article by the Director of the Rothamsted 
 experiments, as 3000 lb. per acre, and by the 
 Table on page 8 of the Summary, which gives 
 the quantities of nitrogen removed by the 
 wheat crops fcr acre, per year, we are enabled, 
 multiplying by twenty-eight years, to give the 
 results in the same tabular form as before. 
 They are as follows : — 
 
 Lb. per acre. 
 Nitrogen in soil originally . . . . 3,000 
 
 Kitrogen in soil finally . . ... . . 2,720 
 
 Loss in soil . . . . . . . . . . 2S0- 
 
 Reraoved by crop (22 lb. x 28 years) . . 616 
 
 Gain of nitrogen . . .-. . . . . 336 
 
 If wo were to deduct 4 lb. per year of nitrogen 
 for ammonia and nitric acid in air, tliis would 
 give 112 lb. which would still leave about 224 lb. 
 of nitrogen gain from unknown source under even 
 wheat growth, and this, after giving full credit 
 to the " reserve " of nitrogen in the soil (as it 
 is included in the above Table), and apart alto- 
 gether from legumes, which did not enter into 
 crops. So that the refuges Nos. 1 and 2 are 
 undermined by the results themselves, and 
 No. 3 — which is altogether undermined by the 
 former continental supporters of the idea — is 
 now the only shelter, and it is zealously made 
 the most of even at the present moment. 
 
46 
 
 The amount gained by the wheat crop, ns 
 shown above, is less than Ihe amount gained 
 by the legume crop, and this is in acoordance 
 with the fact now ascertained, that plants 
 absorb nitrogen from the air in different degrees, 
 and that the degree of the abiUty of cereal is 
 much less than that of legumes. The Rotham- 
 sted data above given, thus provide some evi- 
 dence of the degree of difference, while clearly 
 indicating that iibsorption of nitrogen by cereals 
 from the atmosphere has actually taken place. 
 
 Several instances from the Rothamsted trials, 
 showing the absorption of nitrogen in air by 
 the higher dr green plants, and the fallacy of 
 the " great reserve " as an explanation, might 
 be added, but those given may suffice. True, 
 these field experiments can only give vague 
 evidence, but, such as it is, it goes to show that 
 the Rothamsted experiments prove roughly 
 that green plants are able to fix and utilise free 
 nitrogen of air. This is a matter ot no little 
 value as being data provided by the work of 
 the advocates of the opposite doctrine, and, 
 bearing as it does on a most important subject, 
 this feature may be given a prominent place in 
 the Rothamsted work. 
 
 FEEDING EXPERIMENTS. 
 
 These experiments are of value as advancing 
 the knowledge on the subject at the time they 
 were made, although the information then 
 obtained has to be largely modified by the more 
 exact knowledge now possessed of the char- 
 acters of the various forms of nitrogenous food. 
 Lawes contended against Boussingault, who had 
 concluded that " the comparative values of food 
 stuffs are determined rather by their non- 
 nitrogenous constituents." Liebig arrived at 
 the same conclusion, and he, perhaps even more 
 strongly than Boussingault, looked at the 
 nitrogenous matter as the most important con- 
 stituent of food for the production of both 
 increase and of work." 
 
 The Rothamsted trials were — like most of the 
 trials there — on a large scale, no less than 600 
 sheep, 160 pigs, and 200 oxen were dealt with 
 for this purpose. From the trials it was con- 
 cluded (page 242) that it was rather the supply 
 of TMM-nitrogenous food which regulated both 
 the amount of food consumed by a given live 
 weight in a given time, and also the increase in 
 live ■weight produced ; also that " the amount 
 
47 
 
 of albumiuoids consumed were without much 
 effect on the result when once the necessary 
 minimum of nitrogenous matter in the ration 
 has been passed." The results are summed up 
 on page 245 in the words, " the non-nitrogenous 
 compounds are the main items to be taken into 
 account in making up the value of a cattle food, 
 which value cannot be estimated on a basis of 
 its nitrogen content only." 
 
 The greater knowledge now possessed of the 
 differait forms of nitrogenous food, and of the 
 digestible and indigestible parts of food, prevents 
 the Bothamsted data from being now adopted, 
 yet the information on the subject acquired at 
 Rothamated was a material advance, and was 
 the result of a great amount of labour and cost. 
 
 It was previously considered that animal 
 energy was regulated by the nitrogenous food, 
 and that the energy exerted should be measured 
 by the nitrogen excretion. At Rothamsted it 
 appears to have been proved that the energy 
 is derived from fats and. carbohydrates as well 
 as from albuminoids, and that the energy 
 obtainable may be measured by the heat tfmt 
 each food will generate when burned, but it is con- 
 sidered that a considerable supply of nitrogen 
 is required when the system is overtaxed. 
 
 As to the source Of fat, Liebig held that fat 
 could be elaborated from carbohydrates, but 
 others held that it came from the transformation 
 of albuminoids. The experiments at Rotham- 
 sted show that the amount of fat that could be 
 formed from either fat or albuminoids in food 
 was insufficient to account for the fat actually 
 formed from the animal, and that part must 
 have come from the carbohydrates. 
 
 Some information was also got on the relation 
 of the food consumed to the live weight increase, 
 but it is admitted that by modern practice 
 animals grow more rapidly than the class of 
 animals they experimented upon, and that new 
 experiments are required to get reliable data. 
 
 A determination of the comparative weights 
 of the different parts of the carcases of animals 
 was also made, which must have involved a 
 great amount of labour. They provided data 
 which, though mostly of Uttle use in practice, 
 are well to know, and may at any time provide 
 material that would be difficult elsewhere to 
 obtain. 
 
 An attempt was made to estimate the manure 
 value of food consumed, but it was necessarily 
 based largely on assumption, and perhaps chiefly 
 
48 
 
 On the amount of nitrogen contained by foods. 
 As, however, the losses of nitrogen in the animal, 
 and in the manure heap, etc., were found difficult 
 to determine, and had to be roughly assumed, 
 it is doubtful if the data on the tables drawn 
 up to indicate fair " compensation for manure " 
 from foods, is at all reliable, and, as stated on 
 page 257, " the tables never passed into general 
 use." 
 
 It is frankly admitted (page 258) that the 
 Rothamsted feeding trials will not bear com- 
 parison with the more exact data now obtained 
 by more strictly scientific investigation, but 
 only gave a general idea of the broad principles 
 of animal nutrition. Still the fact remains that 
 the experiments were made on scientific lines, 
 and therefore they are put before the large field 
 operations which are now to be considered. 
 
 (J) StTBOEDINATE RESULTS AT ROTHAMSTED. 
 
 " COMPLETE " AND " PARTIAL " CONTINUOUS 
 MANUEING. 
 
 We have now to consider what are usually 
 regarded as the most important, and which 
 certainly are the most conspicuous, and most 
 costly, of all the trials at Rothamsted. It is 
 the work by which it is identified, and which 
 scores of people go to see annually, and come 
 away mystified. 
 
 Holding in view the very unsuitable plan 
 adopted m this large set of experiments, and 
 the unnatural conditions under which the plants 
 are consequently grown, any one familiar with 
 the subject actuaTly feels an aversion even to 
 study the results, being^ necessarily under the 
 constant conviction that they must be mis- 
 leading so far as bearing on plants grown under 
 naturS conditions. That impression arises 
 whether we consider the extraordinary/ character 
 and the large quantities of manure given, or 
 whether we personally examine the crops on 
 the ground, and notice the yellowish or reddish 
 character of the cereals, the sickly crumpled 
 leaves of the root crops, and, generally, the small 
 crops all over, notwithstanding the heavy 
 manuring. It is thought better, however, to let 
 the experimenters speak for themselves on this 
 point. These faulty features have been referred 
 to in an earUer part of this history, and as it is 
 
49 
 
 possible that they might be regarded merely as 
 a matter of opinion, it is desirable to prevent 
 any dubiety by now showing that they are 
 borne out by the frequent admissions of the 
 Rothamsted experimenters. Their words may 
 therefore now be quoted from the " Summary " 
 which is based on the Beport issued from 
 Rothamsted annually. The italics are new. 
 
 Referring to the mangel trials it is stated 
 (page 95), " owing to the constant removal of 
 organic matter, and the injurious action of the 
 saline manures upon the texture of the soil, the 
 land gets into a bad mechanical condition, very 
 sickly when wet, and drying with a hard crust, 
 so much so that there is occasionally a complete 
 loss of plant from this cause alone." 
 
 Another of many instances indicated the prob- 
 able effect of so large applications of sulphuric 
 acid united with alkalies. It is stated, page 157, 
 that " the continued use of the large applica- 
 tions of ammonium salts (sulphate and chloride 
 of ammonia) has also had an injurious effect 
 upon the reaction of the soil since it behaves as 
 an acid, and continually removes carbonate of 
 lime. The creeping surface vegetation tends 
 to accumulate, and decays into a substance 
 resembUng peat, at the same time the vegetation 
 shrinks into tufts, between which are hare patches 
 of black soil showing an acid reaction to litmus 
 paper. So pronounced had this effect become on 
 plot 5, which received the larger amount of 
 ammonium salts, that the application had been 
 discontinued since 1897 lest the turf should be 
 entirely killed." 
 
 Now this " constant removal of organic 
 matter," and this " injurious action of the saline 
 manures and of ammonia salts," are features 
 that apply to all the field crops at Rothamsted, as 
 they were all similarly treated. This must be 
 regarded as a vitiating feature of the whole work. 
 
 We find the same evidence admitted in regard 
 to the turnip crop as to mangels, thus (page 96), 
 " The surface soil became less easily viorktd, 
 and the tilth, so important for turnips, was fre- 
 quently unsatisfactory, whilst a somewhat im- 
 pervious pan was formed below." 
 
 So also with potatoes. They were (page 95), 
 " Discontinued Decause the crop on the plots 
 receiving no organic manures had fallen to a 
 very low ebb in consequence of the deterioration 
 of the texture of the soil. " 
 
 Cereals are less sensitive than root crops, but 
 even they give a similar indication. The ezperi- 
 
 S 
 
60 
 
 tuents on oats were on very similac lines to the 
 trials on wheat and barley ; they were begun on 
 1869, but were abandoned after ten years, the 
 explanation given (page 92) being that " the 
 field lies comparatively wet, and appears to 
 suffer more than any other fidd from the continuous 
 use of nitrate of soda. As the experiments ran 
 into the cycle of wet seasons from 1873 onwards, 
 it became also impossible to work the land, and 
 the experiments were abandoned after 1878. 
 
 Although the yearly application to the same 
 quantity of 7 cwt. of soluble saline materials 
 would suffice to cause the injury, yet the 
 injurious effects are not confined to «o»i-nitro- 
 genous saline manure, for on page 102 we read. 
 
 The injurious effect of the very large amounts 
 of nitrogen added to some of the plots is very 
 manifest wherever there is more nitrogen than 
 the plant can properly deal with. The leaves 
 have a dark green appearance, are much curled 
 and crinkled, and show an increased tendency to 
 variegation, the chlorophyll collecting in dark 
 green or almost hlach blotches on the lighter 
 background of the leaf. The leaf stalks are often 
 much more coloured and become a bright orange 
 yellow." Again (page 165), "Another feature 
 in these two plots which receive nitrogen but 
 no potash is the weakness of the stems ; short 
 as the grass is it is often laid before it is ready 
 to cut. The grass is also found to be more 
 susceptible to fungoid attacks on these plots 
 than elsewhere." So also (page 162), " On plot 
 1 1-l there is every sign that an excess of nitrogen 
 had been employed, the vegetation is very rank 
 and soft, and tends to grow in tufts with bare 
 patches between. Numerous other instances 
 may be given on the bean, dover, and cereal 
 crops, but those given may suffice. 
 
 No more distinct condemnation of the Botham- 
 sted system of manuring could well be given than 
 is conveyed by these quotations from the 
 " Summary." Except as studies of plant disease 
 the results seem useless to science, while they 
 can form no aid to farm practice, in which no 
 such excessive manuring finds a place. 
 
 The tendency at Bothamsted throughout has 
 been to look upon these failures and unhealthy 
 
51 
 
 crops, not as due to the drugging of the land 
 with salts, but as due to the same plant, with the 
 same root range, being grown year after year in 
 the same soil. This is curiously supposed to 
 have had the result of making the surface soil 
 less easily warhed, and farming a pan. Thus it is 
 stated (page 95), "That swede turnips were grown 
 for fifteen seasons, 1856-1870, but it was 
 found impossible to continue the growth of 
 swedes upon the same land year after year with 
 any success." And the explanation assumed 
 is that this was " mainly due to the incidental 
 circumstances that on growing the same de- 
 scription of crop, with the same comparatively 
 limited and superficial root range for so many 
 years in succession, tlie surface soil became 
 less easUy worked, and the tilth, so important 
 for turnips, was frequently unsatisfactory, whilst 
 for want of variety and depth of root range of the 
 crop, a somewhat impervious pan was formed 
 below. Basing on this assumption the following 
 practical conclusion is ventured on (page 122), 
 
 The experiments show that swede and white 
 turnips cannot be grown repeatedly on the 
 same land, or at even short intervals." 
 
 Now the curious thing is that all this is just the 
 opposite of what every farmer knows takes place 
 whenhe takes two or more successive crops — oats, 
 for instance ; it is just the opposite of what takes 
 place also by continuous growth of the same crop 
 but under proper manuring. As evidence of 
 this, it may be stated that turnips have been 
 grown on land in the Aberdeen Experimental 
 Station for twenty-three years in succession, and 
 the crops still continue to be perfectly healthy. 
 The quantity of crop varied according to the 
 season, but it has run up in good seasons to no 
 less than 30 tons per acre, and instead of the 
 soil becoming sicUy or difficiilt to work or forming 
 a pan the continuous cultivation renders it 
 rather free ; there is no sign of any pan being 
 formed below, and the crops are quite healthy. 
 
 Actually the incidents of continuous upturning 
 and cropping under proper manuring, as found in 
 these trials for twenty-three years, are — loosening 
 of texture by continuous upturning of the soil, 
 the consequent lessening of the organic matter 
 by oxidation, and greater exposure to the 
 attacks by the parasites peculiar to probably 
 every plant. Nothing of the nature of sticky 
 bad tilth, or of pan, occurs; but this would 
 most probably have occurred if immoderate 
 doses of saline manure had been given such as 
 
52 
 
 are given at Botbamsted. In short, what has 
 occurred at Bothamsted is just what might be 
 expected from the unauitdUe marmring, and is 
 exaeUy opposite to what occurs by " continuous 
 cropping " under suitable manuring. It is really 
 surprising that this natural explanation does not 
 appear to have occurred to the experimenters. 
 
 Let us realise more definitely the enormous 
 quantity and cost of manure applied. The 
 general plan of complete manure (see the 
 Summary, page 34), is as follows, and it must 
 be remembered the quantities have been given 
 yearly for over sixty years in the same ground. 
 The calculation below is for fifty years only. 
 
 d 
 
 1 
 
 Manare. 
 
 Quantity per 
 year 
 
 in in Tons 
 Lbs. andCwts. 
 
 Total 
 Quantity in 
 60 Years to 
 each Acre. 
 
 Cost per Acre. 
 
 Each 
 Year. 
 
 For 60 
 Tears. 
 
 2 
 
 Farmyard manure 
 
 14 tons 
 
 = 700 tons 
 
 
 
 3 
 
 No manure 
 
 
 
 
 
 S 
 
 S (Su\. phos. 
 2 I Sul. of pot. 
 g i N. of soda 
 
 3921 
 
 ^°«p7cwts. 
 lOOj 
 
 
 
 
 
 = 17} „ 
 
 £1 13 
 
 £82 10 
 
 
 3 U.ofmg. 
 
 
 
 
 6 
 
 The same plus 
 
 
 
 
 
 
 / Sul. of am. 
 \ Mur. of am. 
 
 100\_ „ 
 100/ - " " 
 
 = 22} „ 
 
 3 
 
 150 
 
 7 
 
 The same plus 
 
 
 
 
 
 
 Am. salts 
 
 400 =10i „ 
 
 = 27 „ 
 
 4 7 
 
 217 10 
 
 8 
 
 The same plus 
 
 
 
 
 
 
 Am. salts 
 
 600 =12i „ 
 
 = 31i „ 
 
 6 14 
 
 285 
 
 9 
 
 The same plus 
 
 
 
 
 
 
 N. of soda 
 
 276 = 0i „ 
 
 = 23J „ 
 
 3 3 
 
 167 10 
 
 16 
 
 The same plus 
 
 
 
 
 
 
 Double soda . . 
 
 650 =12 „ 
 
 = 30 „ 
 
 4 15 
 
 232 10 
 
 19 
 
 Rape cake 
 
 1889 =17 „ 
 
 = *2} „ 
 
 6 19 
 
 297 10 
 
 Let it be borne in mind that the manures used 
 are soluble salts, i.e. combinations of soda, potash, 
 or ammonia with sulphuric acid, an acid which is 
 thus given in enormous quantities. 
 
 Looking at these quantities, and kinds, and 
 costs, we can readUy appreciate the remark on 
 page 8 of the " Summary " that " practical 
 considerations are (were) put on one side in 
 framing the scheme of the experiments." But, 
 it necessarily follows, that the "practical con- 
 clusions" for the guidance of farmers that are 
 given at the end of each chapter dealing with 
 
53 
 
 these experiments, oan have little or no value. 
 And yet it is said (page 9), that " the great object 
 of the Bothamsted experiments is to obtain 
 knowledge that is true everywhere, and to arrive 
 at principles of general application." Actually 
 it oan be true nowhere, except where the soil and 
 the plants are in the same unnatural conditions 
 as at Bothamsted, and no principles can apply 
 generally that are based on so excepttonal 
 conditions. 
 
 What strikes one very forcibly in regard to 
 the " practical conclusions " given at the end 
 of each chapter is (1) their very small number 
 from so huge an amount of work extending 
 over so long a period ; (2) their vague and general 
 nature. They are more in the nature of opinions 
 that would be given by a farmer or manure 
 merchant, on general grounds, than of scientific 
 principles demonstrated by and deduced from 
 actual trials. Thirty-eight pages are devoted 
 to the wheat trial extending over fifty years, 
 and yet there are only three short practical con- 
 clusions, and they are merely of a general nature, 
 and even they are actually based on another 
 set of experiments — i.e. the " rotation " experi- 
 ments — which apparently had to be called in 
 to provide the evidence for any conclusions. 
 This feature applies more or less to all the long 
 continued large field trials in various crops. 
 
 Another feature should be referred to in 
 connection with the wheat experiments, as it 
 is sought to advance something so large as a 
 new " law." It is stated (page 46) under what 
 is called " the law of diminishing returns," that 
 " each increment in the course of production, 
 whether labour or manure, gives rise to a smaller 
 proportionate return, until a point is reached 
 when the value of the increased yield is more than 
 balanced by the outlay required to bring it 
 about." This may be so, and really seems to be 
 so at Bothamsted. But actually, at other places, 
 as has been proved by numerous experiments 
 dealing with natural soil and healthy planj;s, and 
 adopting sensible manuring, exactly the opposite 
 is nearer the truth. The above words " a smaller 
 proportionate return until a point" should be 
 substituted by " a larger proportionate return 
 
54 
 
 until a maximum crop." For, until such a 
 maximum crop is reached (for all crops have 
 a limit, though it is far above those usually 
 produced) each increment of suitable manure 
 not only gives an increased yield, but the addi- 
 tional increase up to the point where a maximum 
 crop is produced is, as a rule, more profitable 
 than the first increase. Thus to give one 
 of many instances — a soil unmanured gave 
 26 cwt. of hay ; the same soil suitably 
 manured at 20s per acre gave 33 cwt. of hay, or 
 7 cwt. extra, which, at 70s per ton, has a value 
 of 24s 6d. Deducting the cost of the manure, 
 there is thus only 48 6d of profit ; but, by doub- 
 ling the manure, and yet keeping it vrithin 
 reasonable limits, at a cost of 40s about 44 cwt. 
 of hay was got (or 18 cwt. extra) having a value 
 of £3 38, and deducting the 40s for manure, this 
 crop gave £1 3s profit. Similar results have been 
 found on grain crops, and it has been frequently 
 repeated in experiment and in practice. The 
 explanation seems to be that if only the quantity 
 of manure actually needful for the crop is given, 
 time is lost by the plant in seeking it out, 
 and it may not ever reach it all ; while, with 
 a sufficiency of manure in the vicinity of the 
 plant, no time is lost in searching for food, 
 and no check is given to vigorous development 
 of the plant. No doubt if an extravagant 
 and impracticable quantity is given beyond 
 what is necessary to produce a maximum crop, 
 and especially if the manure is unsuitable, the 
 profitable return viill certainly materially decrease, 
 for the plants become invalided and approach 
 extinction. This is just what we have in the 
 Rothamsted trials, on which the so-called " law 
 of diminishing returns " is based, for (see tables, 
 pages 34 and 46) the smallest quantity of ammonia 
 salts given was no less than 200 lb. per acre, 
 rising to 400 and 600 lb., and even the equiva- 
 lent of 800 lb. Now the maximum crop is 
 attainable by the lowest of these quantities. No 
 intelligent farmer, however confident about the 
 benefit of manuring, would think of giving 
 more, and, so far as is known, no scientific experi- 
 ment conducted on sound principles, has shown 
 that any larger quantity is necessary to attain 
 a maximum crop. Naturally, therefore, by be- 
 ginning with BO large a quantity, and doubling 
 and trebling and quadrupling the quantity, 
 and hence the cost, the profitable return is 
 diminished. It is like taking four starved 
 men and giving No. 1 more food than he can well 
 
55 
 
 assimilate, but which, while depressing, still 
 leaves him the power to work ; to No. 2, double 
 the quantity, wuoh^would make him ill and nearly 
 unfit to work ; to No. 3, treble the quantity, 
 which makes him half dead, kills him, and renders 
 him unfit to do anything ; and No. 4, quadruple 
 the quantity, which makes death imminent. 
 For the smallest quantity given is more than is 
 required, and more than is given as a rule by 
 any farmer, so that profitable returns is out of 
 the question. Moreover, even by the most 
 excessive manuring given, a maximum crop 
 is never obtained at Bothamsted ; it amounts 
 to less than 6 qrs. of wheat, due doubtless to 
 the continuous drugging of the soil previously 
 referred to. 
 
 Instead of a, " law of diminishing returns " 
 by increasing manure, there might more properly 
 be substituted a " law of increasing returns, 
 by which is meant that a largely increased profit 
 is got by each increment of suitable manure up to 
 the point where a maximum crop is produced. 
 
 SUPPOSED INABILITY OF PLANTS TO 
 UTILISE HITBOGEN OT AIB. 
 
 The experiments at Bothamsted made 
 with the view of confirming or confuting 
 Boussingault's conclusion that green plants 
 do not directly absorb nitrogen yrom the 
 air, deserve the highest commendation for 
 the care that was given in carrying them out. 
 In this trial Lawes was joined by Gilbert and 
 Fugh ; but, most unfortunately, an essential 
 error was made, as had been made also by 
 Boussingault, by growing the plants under so 
 restricted and unnatural conditions that the 
 plants were of the feeblest kind, very smail, 
 never reached full development, and showed 
 evident signs of general inability, and therefore 
 were not fitted to indicate what might be done 
 by plants growing vigorously under natural con- 
 ditions. The plants varied from only one-tenth 
 to less than one-fiftieth of what might be called 
 a " fair-sized " natural plant ; the cereals were 
 merely bunches of leaves, and did not in any 
 single case form anything like a head of grain ; 
 the few seeds got were mostly shrivelled up, 
 or soft and milky, but usually only chafi scales 
 were jnroduced. Incomplete devdo^ment, im- 
 maturity, gerreral disease, and frequent death 
 of the plants showed the failure of the experi- 
 ments, and yet the plants were analysed and the 
 
56 
 
 results used to form part of the data in the table 
 on which the doctrine of the non-absoiption of 
 nitrogen is based 1 It is the common practice 
 of experimenters to discard plants of this nature 
 as absolutely unreliable, and it is most unfor- 
 tunate that this was not done in the case of the 
 Bothamsted trials, for they have gone far to mis- 
 lead us in regard to the action of nitrogen in 
 the feeding of plants for half a century, 
 
 TJNtrSUAL PEOLONQATION OF EXPERIMENTS. 
 
 An outstanding feature of the Eothamsted 
 experiments is their long continuance on the same 
 plan. In no part of the world can a similar 
 continuity be shown. 
 
 But the question arises — is there any utility 
 in the continuance for over sixty years ? At the 
 end of five, eight, or at the most ten years, there 
 was obtained in most cases, if not in every case, 
 all the information that was obtainable. This may 
 be seen by comparing the columns on the table, 
 page 36, of the Summary," when it will be seen 
 that the diSeiences shown at the end of the first 
 ten years were practically identical with those 
 shown at the end of fifty years. It will be 
 seen that plofs Nos. 3, 5, and 10 occupy the 
 first, second, and third places respectively 
 throughout the whole of the first five periods of 
 ten years each ; and that all the other plots 
 occupy the fourth up to the eleventh places 
 respectively in nearly regular order, with slight 
 deviations in only one or two of the periods. 
 In short, no materially different results were 
 found at the end of the fifth decade than were 
 found at the end of the first decade. The vast 
 waste of time, thought, and money on this 
 continuance is amazing, and can be explained, 
 it would seem, only by the facilities of wealth 
 and leaning to notoriety — the one nearly always 
 secures the other. 
 
 We must recognise in the Eothamsted work 
 exceptional persistence, devotion to the work, 
 great outlay, a vast amount of labour, and 
 many results from certain trials of much 
 value, a value which is increased by the fact 
 that, the trials being repeated so frequently, 
 repeated assurance is given of their accuracy. 
 But in regard to the work with which Rothamsted 
 is chiefly identified, viz. the large field trials 
 continued for over sixty years, what strikes one 
 
57 
 
 most foicibly k, on the one hand, the vast outlay 
 of money, time, arid labour, and, on the other 
 hand, a feeling of regret that the methods 
 employed were such as to render the results of 
 these field trials of comparatively little value, 
 and likely to do no little harm by confusing the 
 uninitiated and retarding real progress. 
 
 Modern iNQmntT at Bothamstbd. 
 
 The " history " may here be usefully inter- 
 rupted to consider a certain line of inquiry now 
 going on at Bothamsted, even though it does 
 not — as yet — constitute any advance. Indeed, 
 advance is retarded by the adherence to fanciful 
 ideas. Many would be extremely glad — the 
 writer among the number — ^if Rothamsted 
 would now free itself from its fetters, or creeds, 
 for with its wealth it has an opportunity of 
 doing much good work, though wealth alone is 
 insufficient unless it is associated with a strong 
 desire to get at the truth wherever it may lie. 
 
 But as yet we see little sign of casting o& the 
 fetters. There are only curious indications of 
 shifting the position by seeking new supports 
 as the old ones fail, and, in the case of the last 
 shift, the one support is not merely contradictory 
 of the other, but actually kills the other. The 
 last resort is still another Baeterium viewed along 
 with the old idea of mystery in soil. Thus 
 the present Director at Bothamsted — Mr. A. D. 
 Hall — quite recently gave an address at a 
 meeting of one of the sections of the British 
 Association, in which he discussed, as a profound 
 subject to be approached humbly and reverently, 
 the ancient and long since exploded idea, held now 
 only by those who have not made any study of 
 Agricultural Science, viz. the myaterioua action 
 in the soil regulating plant growth, or, as he 
 described it, unknown factors regulating the 
 fertility of the soil. No doubt with due humility 
 we should approach the unknown in nature, but 
 when known it is equally incumbent that it should 
 be kept reverently clear and not rendered obscure. 
 
 It is the due observance of this duty that 
 demands the elucidation now sought to be made. 
 It is with some reluctance that I have responded 
 to this call, because it seems unkindly to deprive 
 even of false glory, but were this feeling allowed 
 to prevail, there would remain a charge of dis- 
 regard for the higher call of the elucidation of 
 nature in a branch with which I have been 
 identified so long — longer perhaps than any other 
 
58 
 
 One in the kingdom — that some responsibility is 
 felt ; and after all it may prove, and it is hoped 
 it will prove, to be a kind though painful opera- 
 tion. He is a faulty surgeon who is timid, and the 
 straightforward and unreserved method of Lie big 
 in denouncing error, encourages to deal in the 
 same open and fearless way in preserving the 
 light we have, and preventing it from being 
 rendered obscure. 
 
 Now, to seek factors regulating the " fertility 
 of soil " is to hark back to the ancient state of 
 ignorance. The soil produces the crops — was the 
 old idea ; the " humus " and other mysterious 
 things in soil were supposed to produce plant 
 matter ; mysterious actions were supposed by 
 which a clod of soil was changed into a turnip, 
 &c. But we know now, that soil — as soil — ^has 
 exceedingly little to do with the matter — ^that it 
 is largely as the stone walls of a house into which 
 other things are brought to do the work. The 
 whole purposes of the soil are to provide anchor- 
 age for the plant, free root range to secure a con- 
 tinuous supply of water, riddance of injurious 
 matter, and a minute quantity of mineral matter. 
 Essentially this is all. Water culture has shown 
 it. Why, then, raise mystery ? Why mystify the 
 uninitiated by introducing the action, for instance, 
 of the numerous lowly plants and animals that 
 occupy the soil as well as plants, and regard these 
 as factors in production, when we know that such 
 production is independent of them ? By all 
 means let us make use of these other denizens of 
 the soil if their services are helpful in production, 
 and get rid of them if they are hurtful, but do not 
 let us err by regarding them as essential factors in 
 production. 
 
 Mr. Hall revives the mystery, however, and by 
 various outside actors — acids and bacteria — 
 seeks actually to gauge fertility by their means. 
 First there is a harking back to Daubeny's idea of 
 plant food being dissolved out by carbonic acid 
 in sou, and that the matter dissolved by it 
 regulates plant growth — an idea long ago found 
 inapplicable and rejected, as has been the same 
 idea in regard to citric acid. Then comes (2) 
 water, but though it is the main regulator, it is 
 passed over lightly with only a passing reference 
 to the maintenance of the water supply — it seems 
 too simple an explanation. Then comes (3) pro- 
 duction of nitrates by nitrifieation (or oxidation) 
 of ammonical matter by bacteria, and the 
 suggestion that the proportion of nitrate thus 
 formed may regulate production, ignoring that 
 
59 
 
 nitrification is largely nature's method of getting 
 rid of an injurious excess of nitrate, that the 
 nitrate is speedily washed down by rain into the 
 drains, and that as any small proportion left for 
 plants depends on the rain and the riddance, 
 even if it were a factor, it would not be applicable. 
 It may be added that the very small quantity 
 left seems to be nature's method of providing 
 as much nitrogen as will give plants a start, after 
 which they provide themselves from air. 
 
 And now comes (4) an altogether new factor — 
 one which kills the preceding one. For the pro- 
 vision of nitrates to plants by nitrification has 
 hitherto been the much respected doctrine at 
 Rothamsted, and nitrates have been regarded as 
 practically the only form of nitrogen that feeds 
 plants, but, strangely enough, Mr. Hall now goes 
 on to kill it, and to advance in its stead, as the 
 most promising current feature in Bothamsted 
 work, a theory based on the devov/ring of the 
 nitrate-forming bacteria, and the provision by 
 other bacteria, not of nitrate but of ammonia, 
 which at last becomes recognised at Bothamsted 
 as a feeder of plants with nitrogen. 
 
 Now let us see what in plain language this new 
 thing is. The story is this — there are devouring 
 and pernicious organisms in soil as well as benig- 
 nant useful bacteria, and the latter are checked in 
 their action by being preyed on by the former ; 
 but if soil is heated to about boiling water point 
 for twenty-four hours, or treated with an anti- 
 septic for forty -eight hours, the big bad devourers 
 are killed, and the good little ones are left, and, 
 freed from their devourers, multiply enormously, 
 and produce much ammonia, with the result that 
 there is about thirty per cent, increased produce. 
 
 Now all this is very catching. It reminds one 
 of the " Mutual-benefit Society " (symbiosis) of 
 Legumes and Bacteria suggested by Eellriegel, an 
 idea that many happily never accepted, and that 
 is now undermined even by the ablest of bacteri- 
 ologists who once favoured it. I have seen a few 
 agricultural fads in my time. I do not call this 
 new thing a fad, but we must distinguish in it 
 what is known, and what is new and true. Mr. 
 Hall is elated by the novelty, but Mr. Hall is a 
 comparatively young man, and also new to Agri- 
 cultural Science ; as he mellows he will probably 
 be less easily elated, and also not so lax in his 
 statements. Thus in the same address he said 
 "if we go back to the seventeenth century, which 
 we may take as the beginning of organised science" 
 (evidently referring to Agricultural Science as it 
 
60 
 
 was science "' on and how they plant," &c., and 
 " what in the soil," Sea.). In this " ffistory " I 
 had not recognised any Agricultural Science till 
 about the beginning of the nineteenth century, 
 when oxygen was discovered. But Mr. Hall con- 
 tradicts himself lightly by saying in his concluding 
 paragraph, " when science, a child of hardy a 
 center^'* hirth." Again, while the Experimenters 
 in the new inquiry at Eothamsted — Drs. 
 Hutoheson and Eussell — with commendable care 
 indicate that all they hare got is certain facts, 
 and do not imply that they are great, but merely 
 facts that justrEy them only in supposing another 
 action, merely as idea to work out, Mr. Hall, on 
 the other hand, leaps at once to call it " the most 
 important contribution — since — fifty years." 
 Still again, he said it was the most important 
 contribution since " the famous discovery of the 
 fixation of nitrogen aomething like ^/<y years ago." 
 Now what was done in relation to nitrogen fifty 
 years ago was that the Bothamsted Experi- 
 menters supposed they had proved just the 
 opposite, i.e. tne nora-fixation of nitrogen. " Fixa- 
 tion of nitrogen " as generally understood — i.e. 
 direct fixation by green plants — was discovered 
 by the writer only five years ago. But now Mr. 
 Hall states that what he referred to was indirect 
 fixation of nitrogen by bacteria in legumes. Now 
 accepting this curious explanation, even this was 
 discovered (or rather supposed to be) only twenty- 
 five years ago. One must really suppose that he 
 was either in a very confused state, or, that he 
 was actually trying to annex to Rothamsted, as a 
 famous discovery, the gem I had the good fortune 
 to find five years ago, and which Mr. Hall tried to 
 disparage as spurious — actually called it, in 
 language questionably polite, "a mare's nest," 
 but never ventured to specifically criticise it — a 
 style of attack which I shall not imitate — and the 
 discovery has proved too well based to be stifled by 
 ill-natured language. In his position of Director 
 of the most wealthy organisation for agricultural 
 inquiry in the kingdom, Mr. Hall should really be 
 more careful in his utterances, and, unless he gives 
 proofs, we are justified, by his evident laxity, in 
 being chary in accepting his statements. 
 
 Now let us see what Mr. HaU says about soil ? 
 Clearly he would involve us in mystery 
 about it, for he observes " one of the 
 mysteries, many of which we know to be bound 
 up with the practice of agriculture," &c. And 
 the summary of his address runs as follows (the 
 italics and parentheses are mine) ; — 
 
61 
 
 " What is the pause of the fertility of the soil t 
 Elvidently there is no simple solution. There is no 
 single factor to which we can point as the cause ; 
 instead, we have indicated anumber of factors (the 
 four stated were carbonic acid,teattr,nilrate bacteria, 
 and ammonia bacteria, thus omitting the factors of 
 mechanical condition, regidaUon of maintenance of 
 water, variations in drainage, riddance of injurious 
 matter, variation in pests, and variations in mineral 
 food), any one of which {even solvency in carbonic 
 acid) may at a given time become a limiting factor 
 and determine the growth of the plant. All that 
 science can do as yet is to ascertain the existence 
 of these (four) factors one by one, and bring them 
 successively under control ; but, though we have 
 been able to increase production in various ways, 
 we are still far from being able to disentangle all the 
 interesting forces whose resultant is represented by 
 the crop." 
 
 A maze truly 1 Why all this obscurity and 
 humble talk of inability to probe mysteries that 
 do not exist in connection with actual plant 
 growth 7 Doubtless there are many actions 
 in soil by lowly animals and plants that 
 we do not know, but the real question here is. 
 How far — if at all — have they to.be considered in 
 connection with actual plant growth ? Or, the 
 converse question. How much — ^if not all — the 
 effect of these actions is to be regarded as being 
 quite apart from plant growth, and as harmless, 
 or pernicious, according to their nature. It really 
 seems wasted time to scrutinise Mr. Hall's obscure 
 statement, and I might use the words long ago 
 used by Liebig regarding the Bothamsted experi- 
 ments, " If I bestow on these experiments an 
 attention they do not deserve," it is only because 
 I foresee arising from this outcome at Bothamsted 
 a great deal of idle talk and confusion, as well as a 
 check to the progress of Agricultural Science, and 
 not because I see much that is new or anything 
 that is important. Were I to say no more, it 
 might be imagined that this was merely a matter 
 of opinion, and hence it might fail in enect, and I 
 therefore propose to set forth : — 
 
 (1) What is known about soil, and about the 
 causes of variations in crops. 
 
 (2) What is known about life in the soil, or the 
 action in soil of bacteria and higher organisms. 
 
 (3) The new story from Bothamsted about 
 bacteria and higher organisms in soil. 
 
 (4) How far what is now advanced constitutes 
 an3rthing new or useful. 
 
 Let us just look where we stand in regard to 
 
62 
 
 knowledge of the soil, and of the variations of the 
 crops. That there are variations in the crops pro- 
 duced on various fields is undoubted, but they 
 appear to be sufficiently explained generally by 
 variations in the proper provision of anchorage, 
 water, Iminerals, and drainage, apart, of course, 
 from suitable " season," and proper cultivation. 
 Anchorage is seldom at fault, except in very loose 
 soils, such as in sandy or peaty soils ; but the 
 facility for the spread of roots to draw up 
 sufficient water, &c., is possessed by different 
 soils in very different degrees ; still more 
 important is the fact that all degrees of 
 division of the soil particles exist, and hence 
 of water retention, drainage, and capillarity, 
 and hence all degrees of continuous provision of a 
 suitable quantity of water. To a very great extent 
 these are the causes of different production in 
 different soils. Others exist, usually in minor 
 degree, though often seriously, such as differences 
 in the proportion of the essential minerals, in 
 the riddance of injurious matter, in the pro- 
 portion or kind of the lowly plant and animal 
 pests that attack the higher plants, and in 
 the] mechanical state induced by different kinds 
 of cultivation. All these are well-known and 
 accepted facts. And they are sufficient to 
 account for all degrees of production. For any 
 sake let us not introduce unnecessary confusion 
 by fanciful mysteries. Ever since plants were 
 grown in pure water, or in sterilised sand by 
 additions of dead mineral matter, all this has been 
 known, and the ancient mystery attached to soil 
 has disappeared. 
 
 There is too great a tendency to consider that 
 the soil is a medium to grow crops only. Even 
 the worm may say — the soil is for me — ^I actually 
 made it, it is mine, and the numerous animals and 
 plants in it are interlopers. There are numerous 
 animals making a home there, from moles and 
 worms down to amoebse ; there are numerous 
 plants, from wild plants or weeds, and fungi, 
 down to bacteria, each acting in their own way 
 there, and each leaving their traces ; there are 
 numerous kinds of dead matter, from primitive 
 granite (in all its forms of gravel, sand, and clay) 
 dovm to chalk ; and there are numerous forms of 
 organic matter, from forest debris, and vegetable 
 remains, down to peat, and alluvial deposits, all 
 changing according to their nat\u:e, but all serving 
 more or less well, as a medium for plant produc- 
 tion, and that simply by giving anchorage and 
 proper provision of water and minerals. In the 
 
63 
 
 presence of all the decomposing matter from these 
 various sources, doubtless we have numerous 
 conditions, and substances, and actions, but they 
 can only help the plant hy what it needs, and hurt 
 it by what it does not need. It is really against 
 the progress of Agricultural Science to unneces- 
 sarily associate with plant production any un- 
 known, and hence mysterious, actions thus 
 obviously caused, and which the growth of plants 
 in pure substances — such as distilled water and 
 sterilised sand — show do not exist as essentials in 
 plant growth. 
 
 Before setting forth what we know about life 
 in the soil, it may clear the way if we consider 
 (first) what seems to have instigated these trials 
 at Bothamsted. It appears to have been certain 
 incidents, experienced by farmers here or on the 
 continent, in actual practice. Mr. HaU has quoted 
 several instances showing that greater production 
 has followed the heating of soil, and the applica- 
 tion of antiseptics, fiobably many have ob- 
 served such indications. I have at least one very 
 remarkable instance. Carrots were sown in the 
 same soil for over twenty years, and ultimately 
 absolutely failed to grow beyond a certain stage, 
 because they were year after year affected by the 
 well-known carrot maggot. Carbon disulphide 
 was driven into the soil, and the crop of that year 
 was distinctly better, but the crop of the following 
 year was such &a had not in any previous year 
 been produced ; it was almost phenomenal, nearly 
 sixteen tons per acre, and scarcely a mark of the 
 maggot. I naturally attributed part of the result 
 to the killing of the maggot, as it had entirely dis- 
 appeared, and especially (deferred as it was till 
 the second year) to the killing, or absence of the 
 eggs, which would have explained an ordinary 
 crop ; and part of the result — explaining the 
 phenomenal crop — to the killing out of all the 
 many lowly forms of animal and vegetable life 
 that are laiown to prey on higher plants of a 
 sensitive character — such as we find in turnip 
 disease, to which I had devoted much atten- 
 tion in former years. Now Drs. Russell and 
 Hutchinson at Bothamsted, with such experiences 
 in view, have applied themselves to find the ex- 
 planation of this kind of action, and the explana- 
 tion I believe they have so far found — ^let us give 
 due credit for it — but without discovering, so far 
 as I can see, any new, or at leastany^new kind of. 
 
64 
 
 scientific fact. They have, in short, proved, or 
 so far proved — what for all I know to the contrary 
 may already be knovm to bacteriologists — that 
 the bacteria that form ammonia are compara- 
 tively resistant to heat and antiseptics. With 
 this information, what I roughly guessed in the 
 carrot crop, they have more firmly guessed, viz. 
 that what takes place in soil un&r ordinary 
 circumstances is in accordance with the general 
 law of nature that animals prey on plants. 
 
 Now, let us see clearly (second) the Bothamsted 
 position in the matter of life in the soil. The 
 proposed process consists in action on, or by, 
 bacteria. Now we really have had so much about 
 bacteria from Bothamsted, that we must be 
 careful to avoid confusion. We must therefore 
 dissociate the various bacterial actions invoked 
 at Bothamsted. 
 
 There are (1) the bacteria in soil that are tup- 
 posed to absorb free nitrogen from air — the 
 
 Aiotobacter " and others— of which action, 
 as already mentioned, there is no proof; with 
 these bacteria the new theory has nothing 
 to do. 
 
 There are (No. 2) the bacteria which have been 
 proved to change ammoniacal matter into ni- 
 trates ; with these the new theory has nothing to 
 do, except incidentally, that the new process kills 
 them out. 
 
 There is now introduced (No. 3) a third set of 
 bacteria, i.e. the well-known class which changes 
 nitrogenous organic matter (such as exists in soil) 
 into ammonia (directly or indirectly). These 
 form the head and centre of the new theory, which 
 is based on the distinction that this third class of 
 bacteria appear to resist the heat of boiling water 
 and antiseptics. 
 
 Finally, we have introduced a large set of organ- 
 isms — Amoebseand other Protozoa — which devour 
 bacteria — a slaughter that is suggested should 
 be prevented in the case of bacteria No. 3. 
 
 Let us look more closely at this idea that is 
 engaging Bothamsted. In the first place it should 
 be observed that the action depends on heating 
 the soil to boiling point for 24 hours, or applying 
 an antiseptic, such as chloroform, for 48 hours, 
 and hence, to begin with, it is not only something 
 that cannot go on in natural soil, but something 
 that can never, from its nature or cost, be applied 
 in practice, unless a different and suitable anti- 
 septic is found. This, however, in the strictly 
 scientific sense is immaterial. By this proces 
 of sterilisation it appears that the soil is no 
 
65 
 
 absolutely sterilised — the devouring Protozoa 
 stnd most of the bacteria, including, the nitrio 
 bacteria — are killed ; but No. 3— the " ammonia- 
 making " bacteria (I adopt the term given by Mr. 
 Hall) — ^largely resist the action, and, freed now 
 from their devourers, they multiply rapidly, and 
 in correspondence with their increase there is 
 increase of ammonia, and hence crop production 
 is greatly increased. 
 
 Now there are some curious features here. 
 AU that has really been found is, that by partial 
 sterilisation a number of bacteria are left ("of 
 course that will be so, as the sterilisation was 
 only partial), and that they become exceptionally 
 numerous (naturally, having no competitors 
 or enemies) ; and that their increase corresponds 
 with the increase in ammonia (naturally also, 
 if those left are of the ammonia-producing class). 
 But the actual bacterium (No. 3) has not — so 
 far as stated — been separated, cultured, nor 
 identified, nor does it appear that the bacteria 
 observed were anything different from the 
 ordinary bacteria that act in the decomposition of 
 nitrogenous of ganio matter ; further, the aniount 
 of increase of bacteria is stated, but not the 
 increase, nor rate of increase, of ammonia in soil ; * 
 besides, it is not known whether the ammonia 
 found came from the bacteria at all ; and finally 
 the Protozoa have not been detected devouring — 
 devouring is only supposed, and when the 
 supposition is changed to demonstration the 
 discovery indicated will be coniplete. Eeally 
 (as will be seen further on) it would not matter 
 though they were seen devouring — it is known 
 they must do so, if alive. 
 
 Another remarkable thing is, that the new idea 
 undermines two doctrines all along held at 
 Rothamst«d, viz., that nitrification in soils should 
 be maintained, and that ammonia does not 
 provide nitrogen to plants, but only nitrates. 
 Now, however — with the increase of amnionia — 
 it is admitted that there is a corresponding 
 increase in plant production. 
 
 Another curious thing is, that the possibility is 
 ignored — if recognised — of ammonia being set 
 free without bringing bacteria into play at all. 
 
 Between conclusions and suppositions, between 
 
 * In the detailed paper subsequently seen by 
 the author these quantities are given, but that 
 they are derived from bacterial action is only an 
 inference from a corresponding increase in 
 bacteria, and the correspondence is irregularv 
 6 
 
66 
 
 what is old and what is new, between what is 
 sought to be found out, and what is already 
 found out, there appears to be no little con- 
 fusion. 
 
 Let us just consider now what is the present 
 knowledge of these lowly forms of life — ^let us see 
 where we stand — in order to recognise what is new 
 here. 
 
 We have long known (1) that Amoebss and 
 similar organisms exist in all damp soils, ditches, 
 &o., also that they are simple cells with no mouth, 
 but open up anywhere in their covering and 
 absorb matter around them indiscriminately, 
 including consequently microscopic bacteria m 
 great numbers. 
 
 (2) We know also that there is in nature 
 generally a conflict of animal against animal 
 competing for the same kind of food, and even 
 preying on one another, or preying on plants — this 
 preying takes place from man down to the worm, 
 and even down to the simple animal Amoeba prey- 
 ing on the lowly plants called bacteria — it is the 
 mostoommonandmostobviouB lawof nature. We 
 know that the same conflict goes on in the case of 
 plants — the more vigorous seeking the same food 
 and starving out the leas vigorous, and that they 
 also in a limited degree 'prey upon one another, t, e. 
 parasitio or coloiirless plants (lichen, fungi, 
 bacteria, &c.) feed on another plant and often 
 kill it; and, by the same well-known law in 
 nature, the more vigorous bacteria prey upon 
 their weaker brethren. Particularly, as apply- 
 ing to this case, we know that lowly animals such 
 as Amoebaa must prey on the microscopic bacteria 
 — for they cannot avoid it, they necessarily enter 
 in large number with the large particles of food 
 grasped. 
 
 (3) We know also that decomposition of organic 
 matter results in water, carbonic acid, and 
 ammonia ; formerly it was supposed to be a 
 simple matter of oxidation, but, since the advent 
 jf knowledge in regard to bacteria, we have 
 recognised that decomposition is actively carried 
 on by their action of feeding on the material, and 
 forming products of simpler forms — ultimately 
 assuming the forms of water, carbonic acid, and 
 ammonia. But whild ammonia, in smaU quantity, 
 is useful to plants, we know it is injurious in 
 large quantity, and as ammonia is retained by 
 soil, and might therefore accumulate to a hurtful 
 
67 
 
 degree, nature has arranged that another 
 bacterium shall come into play to change the 
 ammonia to nitrate, which is not retained by soil. 
 Therefore to say that conditions being formed 
 that killed out the feeders on bacteria (Amcsbse, 
 &o. ), and killed out the nitrate-forming bacterium, 
 but that did not kill all the ordinary bacteria 
 that form ammonia, restdted in an increase of such 
 bacteria, and an increase of ammonia, is only 
 natural, only what seems bound to take place, 
 and does not introduce anything new, except 
 this — ^that the ammonia-forming bacteria appear to 
 resist heat and antiseptics better than nitrate-form- 
 ing iacteria and protozoa. That seems to be all. 
 Perhaps bacteriologists already know this — if 
 they do not, they would simply record the fact in 
 their bacterial flora, as they are recording daily 
 similar details of the specific characters of any 
 bacterium. 
 
 (4) We recognise that with the exaggerated 
 views of bacteria that recent knowledge is apt to 
 give, there is a tendency to limit decomposition 
 of organic matter to the action of bacteria, and to 
 give to simple direct oxidation no separate power 
 of decomposition. Yet we know that such 
 direct oxidation, especially when assisted by heat, 
 decomposes readily ; for example, if we heat 
 organic matter in a crucible exposed to air, we 
 know that after the heat has been raised to the 
 comparatively low temperature that kills all 
 bacterial Ufe, the orgamc matter is not all 
 decomposed, and yet, by further heat and 
 oxidation alone it is entirely decomposed into 
 water, carbonic acid, and ammonia. 
 
 (5) We have long known that certain sub- 
 stances called antiseptics, such as carbon disul- 
 phide, chloroform, &c., kill bacteria, and also that 
 they kill other low, though much higher organisms, 
 and even higher animals. It is not, I believe, 
 known what is the exact efEeot of these antiseptics 
 on dead organic matter, but as they act on living 
 things, such as bacteria having no nervous 
 system, it is reasonable to suppose that there 
 must be action generally on deaid organic matter, 
 and especially on such simple matter dead or 
 alive of which the bodies of bacteria are com- 
 posed, decomposing theiti to more soluble 
 compounds, and, generally, loosening, or dis- 
 integrating matter so delicate that it is not 
 merely a transparent skin or vesicle, but a 
 vesicle so attenuated that it cannot be seen at all 
 but by the aid of a powerful microscope. There- 
 fore we must not feel certain that part of the 
 
68 
 
 increase in ammonia found may not have been 
 due to the heat or the antiseptics alone causing 
 simple decompositioa of dead organic matter 
 origmally present, and added to by the killing 
 process. For just as oxidation without heat or 
 bacteria decomposes gradually, just as heat with- 
 out oxygen expands, loosens, and disintegrates, 
 and on the advent of oxygen decomposes rapitUj/, 
 so heating and antiseptics may have the same 
 loosening or disintegrating effect on dead organic 
 matter, and on the advent of oxygen the same, 
 but more rapid, result of decomposing without 
 any action by bacteria. Pickering indeed has 
 found, what seems confirmatory of this, viz., 
 that the change by antiseptics is very largely 
 an immediate rendering soluble of the organic 
 matter, up to even 48 per cent, of the organic 
 matter orginally present, and that the increase 
 in ammonia is only gradual. 
 
 We know also (6) that different bacteria have 
 different degrees of resistance to heat, cold, light, 
 and antiseptics. 
 
 All this we know. Now, keeping it in mind, 
 let us compare it with what is now advanced as 
 new. 
 
 The Experimenters are cautious in theirobserva- 
 tions. They say — we have got evidence of 
 certain facts (which they seem to consider are all 
 new),and from these they form an idea (which they 
 also consider new) simply to give a line to work 
 upon in order to get fuller knowledge. The actual 
 words are (the parenthesis is mine), " It had not 
 yet been possible to ascertain definitely whether 
 these Protozoa were active in the soil " (we knou) 
 they are active in damp soil, and must imbibe 
 bacteria), "but the indirect evidence was suffi- 
 ciently good to warrant the assumption of a 
 working hypothesis." This is caution to an ex- 
 cessive degree — it is pretty much like saying 
 that though we know that bacteria exist by the 
 thousand everywhere, we don't know there are 
 any in, or about, the large particles of matter that 
 Amoebae devour — when we prove that there are, 
 and that they are devoured, we shall have 
 changed the hypothesis to a discovery. It would 
 rather be ocular demonstration of what is 
 already absolutely certain^ We hear much of 
 Scottish caution, but it comes into play only under 
 uncertainty. Mr. Hall, however, goes to the other 
 extreme, and leaps recklessly. 
 
69 
 
 WHAT IS THIS STTPPOSBD NEW THINO BBOUOHT 
 0X7T AT ROTHAMSTBD ? 
 
 Mr. Hall goes very much faxther than the 
 experimenteis go ; he says it is a " famous 
 discovery." What is ? One needs to read the 
 account of it two or three times to ensure that it 
 has not escaped the eye, and to pinch oneself 
 to make sure one is not dreaming in not re- 
 cognising the novelty. What is the discovery ? 
 Let us run over the points. 
 
 (1) Is it that animals prey on plants ? Why, 
 that was known in the time of Moses, and per- 
 haps it was even then known, as it is now, that 
 plants also prey on plants. 
 
 (2) Is it that a certain animal — ^the Amoeba — in 
 accordance with that preying instinct — ^preys on 
 the lowly plants, bacteria ? Why, that is a fact 
 as old as the discovery of the Amceba itself, and 
 of its method of feeding, devouring everything 
 indiscriminately within the size of the aperture it 
 forms — the Amoeba cannot avoid it any more 
 than man, in breathing, can avoid swallowing 
 bacteria. 
 
 (3) Is it that certain bacteria produce am- 
 monia ? Why, that is as old as the recognition 
 of bacteriology — it is the well-known action of 
 the most general class of bacteria in effecting the 
 decomposition of nitrogenous organic matter, by 
 which it is changed into water, carbonic acid, and 
 ammonia. 
 
 (4) Is it that when placed in suitable conditions 
 bacteria multiply rapidly by the million ? Well, 
 that is the most elementary fact in every bacterio- 
 logical work. 
 
 (5) Is it that lowly animals and plants (includ- 
 ing bacteria) show different degrees of resistance 
 to heat, cold, light, and unhealthy substances 
 (antiseptics) ? That also is an elementary 
 bacteriological well-known fact. 
 
 (6) Is it that if the ammonia-forming bac- 
 terium is one of the most resistant living forms 
 in soil, and if one partially heats (sterilises) soil, 
 and thus leaves this most resistant form free from 
 natural preys and from uncongenial conditions, 
 multiplication is unusually rapid, and liberation 
 of ammonia is in exact correspondence ? Why, 
 what else could take place ; it is a logical sequence, 
 and a well-known result taken advantage of con- 
 stantly in bacteriological cultures. 
 
 (7) We seem left with only one query that 
 would indicate something new. Is it that 
 annftonja-forniing bacteria ^re exceptionally 
 
70 
 
 resistant to heat and antiseptics ? If they really 
 are so (biit one would like to know the exact 
 conditions of sterilisation), and if it is not already 
 known to bacteriologists, that would be something 
 new — nothing great — but yet useful to knOw. 
 
 Apparently the work at Rothamsted is now to 
 be applied to detecting the Amceba devouring the 
 bacteria ; and its detection, we suppose, will be 
 proclaimed. Well, it is over thirty years ago 
 since I detected it (as all close examiners of it 
 have) devouring a very much larger particle 
 than thousands of bacteria combined, and how 
 such particles could be freed from bacteria is 
 difficult to understand. 
 
 One question has been deferred that would 
 indeed mark this inquiry as " famous " in a 
 certain sense, i.e. famous to Bothamated, viz. : — 
 
 (8) Is it that ammonia feeds plants with 
 nitrogen, since production has increased 'pro 
 rata with the liberation of ammonia. Well, 
 that is an action that I, and others, have always 
 held, but it has hitherto been denied at Rotham- 
 sted, where it has been held that nitrates 
 only can provide plants with their nitrogen, 
 and that ammonia had first to be changed to 
 nitrates by bacteria before it is of any use. One 
 reason I had for rejecting that doctrine was that 
 I never saw any difference in my experiments 
 between the action of ammonia salts and nitrate 
 salts. Another reason is that ammonia is one 
 of the three plant essentials (phosphate and 
 potash being the other two) which nature care- 
 jully conserves in the soil, while she lets nitrate 
 poM of freely to the drains, and even provides 
 a bacterium to effect the change from ammonia 
 to nitrates to secure this riddance, for the reason 
 probably that much ammonia is harmful. The 
 Rothamsted Experimenters and others are 
 responsible for this nitrate sole-food doctrine so 
 firmly pronounced that it had to be taught. 
 That is a discovery to Rothamsted itself, and it is 
 to be hoped that it will be " famous " by leading 
 that organisation to free itself from other de- 
 lusions peculiar to it. For, as they proclaim — 
 or rather prove without proclaiming — that they 
 were altogether wrong in this respect, it may 
 dispose them to think they may actually be 
 wrong in other respects. 
 
 So that it comes to this — that this new idea, 
 given out so profoundly and triumphantly, is 
 really very like a repetition of the kind of state- 
 ment that caused Leibig to say of certain Rotham- 
 gtpd work, " it shows what could be said tQ 
 
71 
 
 larmera at a time when science was not under- 
 stood." Let us hope for something better 
 later on from an organisation that has so much 
 wealth at command. 
 
 One good result follows from this inquiry — 
 I wish to give Rothamsted all the credit I can — 
 and that is, that it may help people generally 
 to be careful not to forget what they know, in 
 other words, to realise constantly and clearly 
 that the soil is not made for the growth of agn- 
 cvitural crops alone, that there are scores of 
 plants and scores of animals living there, and 
 competing with one another for what the soil 
 may contain, and while some of these may assist 
 his crops (such as the ammonia-forming bacteria 
 hastening decomposition of organic matter, and 
 the nitrate-forming bacteria getting rid of 
 hurtful excess of ammonia, and getting rid of 
 its own excess), they are mostly to be regarded 
 as not Mpful to crops — but are either harmleaa or 
 are hurtful by competition or attacks, and therefore 
 farmers should use every means, when the land 
 is free of crops, to get rid of these enemies by 
 practicable methods. I hardly think the opera- 
 tion of heating the soil, or even applying anti- 
 septics, is likely to be available in practice, but 
 there are others which are practicable and actually 
 practised, such as upturning to frost, frequent 
 stirring to expose to oxygen of air, applications 
 of Ume, drainage, and generally avoidance of 
 conditions helpful to crop pests. 
 
VIII. 
 
 WORK BY THE AGRICULTURAL 
 RESEARCH ASSOCIATION, ABERDEEN. 
 
 This Association was established in 1875, and 
 has continued its investigations uninterrviptedly 
 since that time. It was originated by several 
 prominent men in Aberdeenshire — landowners, 
 farmers, and others — who felt strongly that 
 agricultural investigation on scientific lines was 
 not carried out to the extent that the probable 
 benefit to agriculture demanded. Although 
 that feeling could not be called general in the 
 district, yet it was sufficiently appreciated to 
 secure a moderate income by contribution, and 
 this voluntary local support has been maintained 
 up to the present time, assisted latterly by a, 
 small Oovernment grant, and occasionally by 
 grants from public bodies. 
 
 The object of the Association was defined to 
 be : — " To obtain reliable and useful information 
 on agricultural subjects by means of scientific 
 investigations and practical experiments, and 
 to disseminate the information." 
 
 Although thus fixed to be investigation on 
 scientific lines, yet, originated as it was by men 
 directly interested in land, it was natural that 
 the subjects chosen for inquiry would be such as 
 promised to be of direct benefit in agricultural 
 practice. But the more urgent of these subjects 
 having been dealt with, the work has latterly 
 consisted more of the nature of pure research, 
 such as the subject just completed, and which 
 may be regarded as the crowning feature of the 
 whole work, viz., the discovery that plants 
 directly utilise the free nitrogen in the air, and also 
 the means by which they utilise it. 
 
 The initiators of the organisation, although 
 more or less familiar with science, wisely, at the 
 outset, disclaimed their ability to guide the 
 scientific work, and placed it unreservedly in 
 the hands of Mr. Thomas Jamieson, F.I.C, 
 
73 
 
 Lectuiei in A^icultuial Science in Aberdeen 
 University, who has directed the work up to the 
 present time^ 
 
 It would be impossible within the limits of this 
 history to enter into detail of the mass of work 
 that has been done during these thirty-five 
 years. It is, besides, unnecessary in a History 
 of the Progress of Agricultural Science, which is 
 a record of work, with only such detail as renders 
 clear its nature, and the incidents attending it. 
 This object may best be served by (as in the case 
 of the Eothamsted work) stating, in the first 
 place, the results briefly in tabular form, dis- 
 tinguishing between the more useful work and 
 the subor(£nate work, bringing to the front those 
 results that appear to present foundational 
 advances in agricultural science, and following 
 that table by brief explanatory observations on 
 the leading subjects. 
 
 Certain features in the methods adopted should 
 be mentioned. 
 
 1. Experience of large field plots had shown 
 their unreliable character for true comparison, 
 due to differences in physical character, depth 
 of soil, drainage, &o., as well as to the impossi- 
 bility of getting the whole work of many com- 
 parative plots done under the same climatic con- 
 ditions, and even the same manual labour. 
 Therefore, small plots were chosen in which all 
 these defects were avoided ; the plots, however, 
 being still of considerable size, viz., about 
 48 sq. yds. — i.e. one-hundredth acre. Latterly, 
 one-tenth of this size w^as used, but in that case 
 the whole soil was lifted, mixed, and returned 
 in equal quantity to the subsoil, which had been 
 renidecfid uniform, as well as the drainage. 
 
 2. The experiments were carried out in five 
 different parts of Aberdeenshire, thus giving 
 evidence from different soila — clay, sandy, and 
 loamy. They were repeated in two English 
 counties — Kent and Huntingdon, and latterly 
 in Sussex at five different stations. 
 
 3. Each experiment was exactly duplicated 
 at each station, thus giving ten direct answers 
 to each question, and correcting any accidental 
 deviation ; while many plots, approximately 
 alike, gave further confirmation. 
 
 4. While several subjects were usually on 
 hand, there was always one leading subject, which 
 ^^s s^dhered to for several years — usuallv fiv? 
 
74 
 
 or seven — until it seemed to be thoroughly 
 worked out, and assurance had been given of the 
 accuracy of the conclusions. 
 
 OHIBF EBSTTLTS. 
 
 1. The ability of plants to utilise mineral 
 phosphate of lime, though insoluble in water. 
 
 (Practical value — estimated by one intimate 
 with the manure trade and its statistics that 
 £50,000 annual saving has thus been effected in 
 manures used in Aberdeenshire alone, and one 
 million pounds annually in the use of about one 
 million tons of phosphate generally.) 
 
 2. The existence of an aperture at the ex- 
 tremity of root hairs. 
 
 (Explaining how matter insoluble in water 
 can enter the plant.) 
 
 3. Primary (or predisposing) cause of turnip 
 disease. 
 
 (Found to be a state of weakness in the plant, 
 which is induced by a variety of conditions, and 
 provides the opportunity for the action of the 
 special fungus that characterises the disease ; 
 the usual cause of weakness is — acid manure, 
 i.e. superphosphate. 
 
 Practical value — means ascertained to avoid, 
 or lessen, the disease.) 
 
 4. Definition of soil character, as bearing on 
 its varying suitability for plant growth — parti- 
 cularly clover. 
 
 (Suitability found to depend largely on the 
 equal distribution of organic matter over the soil 
 
 E articles of various sizes, and on an exceptionally 
 igh proportion of organic matter associated with 
 the finest particles. 
 
 Practical value — improvement of soil by 
 methods to adjust such proportions.) 
 
 6. Self-cross fertilisation of cereals and grasses 
 gij the large scale, 
 
75 
 
 (Practical value— iucrease of produce by about 
 one-fourth). 
 
 6. Method of reproduction in cereals and 
 
 (The two feathery structures in the flower of 
 these groups of plants (graminese) found to be 
 structures to assist cross-fertilisation, and not 
 stigmas as formerly supposed. The real stigma 
 is the viscid crown of the ovary. This fact 
 explains and confirms self-cross fertilisation.) 
 
 7. Plasticity (or ability to alter form) of rye 
 grass, and relation of this plasticity to the per- 
 manence of rye grass under old pasture condi- 
 tions, and its bearing also on the evolution of 
 
 (Practical value — method of retaining good 
 permanent rye grass pasture.) 
 
 8. Reduction of the minerals essential to 
 plants to f,ve in number, by the exclusion of 
 sulphur and chlorine. 
 
 9. Discovery of the direct absorption and 
 utilisation by plants of nitrogen in air, and of 
 the organs by which the absorption is performed. 
 
 (Ascertained by means of microscopic examina- 
 tion of the structure, growth, contents, and action 
 of specialised hairs found on youngest leaves ; 
 finding their constant occurrence in plants 
 in varying degree — a degree corresponding 
 to their nitrogen contents or demands. Con- 
 firmed (a) by gravimetric evidence from plants 
 grown under strict control in water culture ; 
 (6) by small and large growth in soil ; (c) by 
 growth on large scale in nature ; (d) by investiga- 
 tions by Zemplen, Both, PoUacci, and Mamelie 
 on the Continent. 
 
 Practical value — means of acquiring nitrogen 
 for crops direct from nature, and thus avoiding, 
 or lessening, the purchase of costly artificial 
 BJtrogenons ms^nures.) 
 
76 
 
 SITBOBDINATB BBSTJLTS. 
 
 10. Determination of the relative efleots on 
 different crops of the different forms of nitro- 
 genous, phosphatio, and potassic manures. 
 
 11. Determination of the composition of 
 turnips and oats, as modified by different 
 manures. 
 
 12. Determination of the relative productive 
 value, and permanence of different grasses. 
 
 13. Demonstration of the characters of the 
 roots of grasses and clovers. 
 
 14. Explanation of failures in clover crop. 
 
 15. Numerous inquiries, with the object of 
 directly aiding agricultural practice, such as 
 methods of sowing the usual crops ; periods of 
 harvesting ; storage of grain ; utilisation of 
 turnips, &c. 
 
 16. Farm conducted for five years for illustra- 
 tion of manuring, and of improvements in farm 
 practice. 
 
 Some of these inquiries were confirmed in 
 temporary experimental stations in England 
 in the Oolitic (limey clay) soil of Huntingdon, and 
 the chalky soil of Kent, under the same Associa- 
 tion and direction. Also, for twelve years, a 
 unique confirmation was given by the establish- 
 ment of a similar Association in the south of 
 England — " The Sussex Association for the Im- 
 
 Erovement of Agriculture " — supported liberally 
 y landowners in that county, and placed under 
 Mr. Jamieson's direction. By this means, the 
 trials were exactly duplicated under the great 
 difference of soils and climatic conditions pre- 
 sented by those of the south of England, as com- 
 pared with those in the north of Scotland. 
 
 The results of these investigations have been 
 fully detailed in the Reports published annually 
 by the Association, and recently a " Summary " 
 has been published (bylOliver & Boyd, Edinburgh) 
 for the use of farmers, entitled. The Farmera' 
 Handbook, which embodies, in simple form, all 
 the results expressed in such a way as may 
 easily be understood and applied in practice, 
 
77 
 
 Sfmsiaby or the Lbading Investigations. 
 
 (1) AVAILABIUTY OP INSOLUBLH PHOSPHATB OF 
 LIME. 
 
 It seems needless to say much on the avail- 
 ability of insoluble phosphate of lime by plants, 
 because it is a fact now universally accepted, 
 jtat as before the Association's investigations 
 the reverse was universally held. It has been 
 verified by numerous investigators, as well as 
 by practice on the large scale. Amoni these 
 investigators should be mentioned Graideau in 
 France (wKo indeed was working simultaneously 
 on the same subject), Aitken in Scotland, and 
 many others here, on the Continent, and in 
 America. Still, as a matter of history, it is well 
 to note that the opposite doctrine was so firmly 
 held that the Association had to adhere for 
 seven years to its trials in order to meet the con- 
 troversies that arose, and which were called the 
 " Battle of the Phosphates." It is an instance 
 of how very difficult it is to efface an erroneous 
 doctrine once it is well established. 
 
 It has been abundantly proved that if amor- 
 phous (non- crystalline) phosphate of lime is 
 ground down to a sufficiently fine powder, it acts 
 as well as soluble phosphate (superphdsphate). At 
 the time of the Association's trials (1875) the 
 mechanical methods of grinding mineral phos- 
 phates were not so perfect as those of the present 
 day, and the results on crops were usually 
 slightly under those from soluble phosphate, 
 but now that improved grinding produces an 
 almost impalpable powder, the results from 
 such insoluble phosphate of lime are found to 
 be ec[ual to the results from soluble phosphate. 
 Although the division by grinding can never be 
 so fine as by solution or precipitation, yet some 
 contend that in practice insoluble phosphate 
 frequently surpasses the ultimate effect of soluble 
 phosphate, although the first appearance may 
 not be so good, a circumstance explained by the 
 rapidity of action, but the unduly rapid growth 
 and the acidity of soluble phosphate, weaken 
 sensitive plants such as tijrhips, and root crops 
 generally, and hence give rise to disease. Thus 
 equality, at least, is assured if the division is 
 sufficiently fine. 
 
 Apart from the scientific value of the informa- 
 tion thus obtained, the discovery has had an 
 enormous effect on practice, not so much by 
 
78 
 
 farmers using insoluble phosphate alone, because 
 they now usually employ mixed manures con- 
 taining all the ingredients essential to plants, 
 but by the large use of insoluble phosphates by 
 manure manufacturers in making up these 
 mixtures, now that insoluble phosphate has an 
 admitted value. The consequence is, that not 
 only may the farmer provide himself with 
 phosphate at less cost, but the price of phosphates 
 has been lowered generally, both by mineral 
 phosphate taking the place of more costly bones, 
 and by full advantage being taken of the immense 
 deposits of mineral phosphates in various parts 
 of the wjrld. 
 
 Another result of the discovery was the in- 
 centive given to make use of the insoluble 
 phosphate of lime contained by the waste slag of 
 iron manufacture, which, prior to these investi- 
 gations, was thrown aside as useless. At the 
 present time an enormous quantity of this waste 
 product is now ground to a fine powder, and, 
 under the name of " slag," is used as manure to 
 a very large extent. 
 
 It seems fitting, as arising from this discovery, 
 to note here a feature that, in a marked degree, 
 has attended the work of this Association, viz., 
 constant opposition, and the obvious explana- 
 tion. It seems fitting also to allude to it in a 
 history of progress, by way of indicating obstacles 
 to progress. 
 
 This, the first discovery of the Association, 
 was unfortunately directly opposed to the 
 doctrine clearly and firmly expressed by the 
 most prominent and authoritative men associated 
 with agricultural science in the kingdom, viz., 
 the late Dr. Voeloker, chemist to the Boyal 
 Agricultural Society (who was indeed the fore- 
 most opponent of the effectiveness of insoluble 
 phosphate), and Mr. J. B. Lawes of Bothamsted, 
 who neld similar views, who then had almost a 
 monopoly of agricultural experimenting, and 
 whose commercial interest in the sale of super- 
 phosphate had not at that time ceased. Under 
 these circumstances, opposition, and attempted 
 repression, was inevitable, unless scientific 
 "magnanimity prevailed. For a new and small 
 body away in the far north of Scotland to question 
 the authoritative dictum was intolerable. The 
 old doctrine authoritatively given out had to 
 be defended by the leaders, and to the defence 
 naturally came a number of younger colleagues, 
 who have now succeeded them in position or 
 influence. The seven years' " Battle of the 
 
79 
 
 Phosphates " was very keen, as is ever the case 
 when not only dogma, but influence and au- 
 thority, have to be contended with. But though 
 won, it left, unfortunately, no little rancour 
 in the defeated party. This might have died 
 out but for the continued activity of the Associa- 
 tion, and the periodical announcement of fresh 
 results. These kept aUve the old feeling, which 
 showed itself not only by opposition to every 
 new discovery of the Association, but a malign 
 furtive influence has been traced into Govern- 
 ment Departments, Councils, Committees, and 
 private individuals here and abroad. The 
 actors have such satisfaction as is derivable from 
 succeeding in giving a great deal of trouble, 
 occasional anxiety, and hindrance of work 
 and progress ; on the other hand, thera are 
 compensations, for the fact that the unusual 
 opposition was steadily withstood, gives greater 
 assurance of accuracy, while difficulties always 
 enhance the value of success, and perhaps even 
 serve to stimulate. 
 
 (2) APBETUBE IN ROOT HAIRS. 
 
 The inquiry on root hairs was suggested by 
 the difficulty of comprehending how insoluble 
 phosphate of lime could possibly enter plants, 
 for entrance was evidently by the very minute 
 hairs on the youngest parts of the rootlets, and 
 these hairs were understood to be closed through- 
 out. It was generally accepted, therefore, that 
 plant food must be dissolved by an acid either 
 in the soil, or exuded by the plant hairs, and 
 this supposition was supported by the statement 
 that the hairs gave a faint acid reaction. But 
 obviously the decomposing matter of soil, which 
 closely envelopes the plant hairs, would also 
 give such a reaction by the carbonic acid arising 
 &om this decomposition, and it was found that 
 when plants are grown in pure sand, there is 
 either no acid reaction, or only such a faint 
 indication of acidity as could not account for 
 the rapid solution of such an inert substance 
 as mineral phosphate of lime. tJltimately it was 
 found that, closed as the root hairs seemed to 
 be at the extremity, it was only a semblance, for 
 careful microscopic examination xmder different 
 light and focus brought out the existence of an 
 aperture, and the evidence was such as precluded 
 explanation by optical illusions, that are apt to 
 be given under high powers of the microscope. 
 Not only has the aperture been observed in every 
 
80 
 
 Elatit carefully examined, and not only has it 
 een confirmed by the well-known staining 
 processes, but (1) the aperture has been seen to 
 be continuous with an inner channel of the hair ; 
 (2) particles have often been observed passing 
 along this channel ; (3) occasionally a particle is 
 observed half way into the aperture, while 
 (4) on drying the hair there frequently can be 
 seen an emission of matter coming distinctly 
 from the aperture, the latter two facts setting 
 aside any idea of optical illusion. It was found 
 that the size of this aperture, though small, 
 is sufficiently large to admit the finer particles 
 of ground phosphates. 
 
 It is not known that botanists have generally 
 accepted the existence of an aperture ; here 
 again the difficulty of overcoming dogma has 
 been experienced. In the interest of progress 
 may now be shown (1) that all was done that 
 could be done to subject the discovery to skilled 
 criticism, and (2) the methods of dogma defence. 
 An article on the subject was read by the author 
 before the Botanical Society of Edinburgh 
 many years ago, and the apertures in several 
 plants were shown under the microscope to the 
 members ; the formation deemed an apertuTe 
 was admitted by all to be seen ; the demonstra- 
 tion evoked no dissent. The President — 
 Professor Balfour of Edinburgh— requested the 
 loan of my specimens, which was given ; he 
 suggested a visit by me to the Botanic Gardens 
 next day, when other plants growing there, and 
 selected by him, might be examjaed — a proposal 
 which was willingly accepted. The forenoon 
 was spent by him, his assistant, and myself in 
 the examination, with the result that in each 
 plant selected, the aperture, or what to aU appear- 
 ance was an aperture, was found. In the words 
 of his assistant (who Professor Balfour said was 
 a more skilled microscopist than himself) " if it 
 was not an aperture, it was very like one." It 
 is admitted ttiat this result did not necessitate 
 actual acceptance, but it called for provisional 
 recognition, till the evidence could be confirmed 
 or refuted. Professor Balfour undertook to 
 examine the point further by means of the 
 well-known staining process, which had already 
 been applied. This examination should have led 
 to refutation, to acceptance, or at least to 
 uncertainty in regard to both theories. It 
 
81 
 
 may hardly be believed that the jnatter ended 
 there, "(yithout any of the three positions being 
 adopted, but only — silence. After a lapse of 
 time, a courteous reminder by the author elicited 
 from Professor Balfour the reply that an oppor- 
 tunity to examine had not occurred, but giving 
 a renewal of his undertaking to do so. Another 
 reminder had a similar result. And here the 
 matter ended. It could not well be driven 
 farther. Silence might mean assent, or it 
 might mean impossibility to refute, yet adher- 
 ence to dogma. Under these circumstances it 
 would be interesting to know what Professor 
 Balfour now teaches to his students, and whether 
 he admits that he admitted the demonstration, 
 and failed in his undertaking to confute or 
 confirm the existence of an aperture. To still 
 uphold the negative doctrine seems equivalent 
 to this position^" there appeared by the 
 skilled microscopic examination of myself and 
 my assistant to be an aperture ; it is held by the 
 discoverer to have been confirmed by staining 
 and other observations ; I have not been able 
 by staining testa to refute it ; there ia no reason 
 why there ahould not be an aperture, but we 
 never saw an aperture before ; to admit that 
 there is an aperture would imply that we had 
 been faulty in examination and teaching error ; 
 after all it is difficult to be absolutely certain 
 that there is an aperture — I shall hold on to the 
 old idea." It is most difficult to advance under 
 such infiuences by those in recognised positions. 
 
 Even in the best of the boianical works it 
 does not appear that the structure of the tip of 
 the root hair has received what could be called 
 intensive or specialised inquiry on the particular 
 question of an aperture, and it will be evident 
 that the failure to observe an aperture is a much 
 weaker position than success in observing it — the 
 one is negative, the other ia positive ; the one is 
 the result of ordinary observation without 
 special scrutiny or aim ; the other is specialised 
 painstaking observation with a direct aim. 
 Schwartz has specially examined root hairs but 
 with reference specially to membrane thickenings ; 
 he found such thickeninga at various parts, and 
 sometimes at the extremity, but the illustrations 
 of these thickenings at the extremity so closely 
 resemble the appearances assumed by the aper- 
 tiures under certain conditions of light and focus, 
 
 7 
 
82 
 
 as to suggest that be inadvertently included the 
 appearance at the tips among other thickenings, 
 without special scrutiny for an aperture. 
 Zacharias also has examined these "thickenings," 
 but his inquiry was mostly on the hairs of 
 aquatic plants, and does not directly touch on 
 the formation of the extremity. He, however, 
 goes so far as to speak of a " hole," but he 
 supposed it to be due to bursting ; this bursting 
 however, is frequently mentioned by him, and it 
 is significant to note that it occurs generally, 
 if not always, at the tip. Again, Gasparini has 
 said that the hairs in certain circumstances 
 open at their summit, and that they shed a portion 
 of their contents, retaining afterwards " a 
 little hole " more or less recognisabk at the 
 summit. If they open to shed, it is reasonable to 
 suppose that they open to receive. 
 
 Under all these circumstances it would seem 
 that the evidences of an aperture at the end of 
 root hairs at least overweighs the merely 
 negative, or — did not happen to see — evidence 
 against it, and, taken in connection (1) with the 
 absence of acidity under pure conditions, (2) with 
 the rapid utilisation of insoluble phosphate, and 
 (3) the failure to refute — the minute aperture at 
 the tip of the root hairs appears to be reasonably 
 well established. 
 
 (3) PRIMARY (OE predisposing) CAUSE OF 
 TURNIP DISEASE. 
 
 The disease known by the name of " finger- 
 and-toe " or " club root " frequently ruins the 
 turnip crop over wide districts in certain seasons, 
 and to no little extent in all seasons. In the early 
 period of the Association's investigations various 
 ideas were held as to the cause, and were mostly 
 followed out, but without much success, except 
 to find that the application of manures treated 
 with sulphuric acid (superphosphate) was followed 
 conspicuously by disease. This could not be 
 regarded as the cause, however, because several 
 other conditions (experienced in the trials, and 
 also reported in answers to a series of questidns 
 issued to over a hundred farmers) such as bad 
 drainage, working the soil in a wet state, ex- 
 ceptionally wet or dry seasons, or even wind 
 at an early stage of the plant, seemed also to 
 give rise to it, although none of these conditions 
 were so distinct and certain concomitants of the 
 disease as the use of acid manures. 
 
 At this stage, Woronin of Sweden found that 
 
83 
 
 the diseased portions were permeated by a. 
 minute fungus (named by him Plasmodiophora 
 brassicce), and he thus defined, for the first time, 
 the nature of the disease. This was a signal 
 advance. But, considering that this fungus 
 appears to be present universally, as it is found 
 wherever turnips are grown under bad conditions, 
 and that only under certain, circvmstances does 
 the disease appear, the fungus cannot be regarded 
 as the cause, but merely as the feature associated 
 with or characterising the disease. 
 
 Briefly, after several years' trials, it was found 
 that the primary cause is weakness of the plant, 
 a condition which renders it an easy prey to the 
 fungus ever present, and waiting its opportunity ; 
 that this weakness may arise from a variety of 
 conditions (those previously mentioned) ; but 
 that in practice it arises chiefly from the use of 
 soluble acid manures which force on the young 
 plant at a rapid and unhealthy rate, and it is at 
 this early stage that the plant is attacked. In 
 other words, weakness alone caimot give rise 
 to the fungus — ^it can give rise merely to dis- 
 organisation, slight development, or death ; 
 the fungus alone cannot give rise to the disease, 
 otherwise in an infected soil it would exterminate 
 all the plants, whereas it is found that it is 
 limited to certain plants, and to certain parts 
 specially treated, or specially circumstanced. 
 Just as in animals (including man) bacteria may 
 abound, yet the strong ward off the effect, while 
 the weak succumb to it ; so in turnip disease, the 
 predisposing condition of weakness precedes 
 and permits the action of the fungus, which 
 determines the characteristic form of the disease. 
 There is indeed one condition under which the 
 fungus alone would cause disease, viz. attack 
 by the fungus in " mass," as it is called, i.e. by 
 such masses of fungus surrounding the plant as 
 would alone constitute a cause by weakness. 
 
 The remedies suggested were : (1) the avoidance 
 of conditions that would weaken the turnip plant, 
 and especially the avoidance of acid manures, 
 and also efforts to strengthen the plant by the 
 provision of suitable food, and by attention to 
 working the land only in a dry state ; (2) the 
 converse treatment at same time, i.e. the 
 adoption of practices that would counteract 
 vigorous fungoid life, such as heavy liming, 
 drainage, aeration by cultivation, and leaving 
 drills open a day before covering in dung. 
 
 This cause of turnip disease, i.e. weakness 
 usually brought about by acid manures, is one 
 
84 
 
 of thb few findings of the Asaoclation that have 
 been accepted without opposition — probably 
 due to the fact that it did not overturn any 
 accepted dogma. 
 
 (4) PHYSICAL PEATtTEBS OS SOIL BEOtTLATING 
 PEBTIMTy. 
 
 A request being made for an inquiry by the 
 Association into the frequent failure of clover 
 to grow on good black soil that suited other 
 crops well, the subject was adopted, and several 
 lines of investigation were followed. Ultimately 
 the failure was found to be due to a certain 
 physical state of soil, but the inquiry led unex- 
 pectedly to the discovery of an unrecognised 
 feature of soil. The determination of organic 
 matter in soil is a regular process in analysis, 
 and one which gives no little indication of its 
 character and abiUtiea. But the determination 
 of organic matter associated with the various 
 degrees of division of particles in the soil, which 
 is rarely carried out, brought out the remarkable 
 feature that in the finest particles of soil (viz., 
 those particles that, when shaken up with water, 
 remain suspended in the water after resting one 
 minute), the proportion of organic matter is not 
 only very much higher than in all the other 
 states of division, but the proportion leaps up 
 so suddenly as to make a natural line of demarca- 
 tion between this very finest portion on the ojie 
 hand, and, on the other, the rougher though still 
 fine particles of soil, in regard to the organic 
 matter associated. Thus while the fine particles 
 (but not so fine as to remain suspended in water), 
 may be associated with say 10 per cent, of 
 organic matter, the proportion associated with 
 the finest, lightest, or suspensory particles leaps 
 up abruptly to 20 or even 40 per cent. The full 
 Bignifica,noe of this feature may be greater than 
 is known, but the higher proportion seems at 
 least to be associated with the retention of 
 moisture about the finest parts of the rootlets 
 and root hairs, thus giving less liability to inter- 
 mittent dryness which would be injurious to 
 these delicate parts. 
 
 It was also indicated by these trials that unless 
 the soil is well balanced in regard to the propor- 
 tion of organic matter associated with each of 
 the different states of division, it fails to give the 
 texture suited to the growth of at least certain 
 plants ; that if the proportion of organjo matter 
 associated with the finer particles is too low, the 
 
85 
 
 soil will be too cohesive; while if the oi'gaiiic 
 matter associated with the rougher particles is 
 too low it will not be cohesive enough, and is 
 therefore liable, by frost and cultivation, to the 
 formation of cavities ; these cavities become 
 filled alternately with air (by withdrawal of 
 water by drainage), and then with water of rain, 
 which, on freezing, upheaves the soil, both 
 actions giving rise to open cavities in which roots 
 are exposed to air, thus affecting injuriously 
 sensitive plants, that, in their young state, have 
 fine delicate roots. The easy upheaval by frost 
 alone frequently entirely detaches the clover 
 plant from its anchorage in the soil. Such a 
 soil has been found imsuited for clover growth — 
 the abundant young plants disappearing to the 
 farmer unaccountably, especially as it occurs 
 often in the blackest soil, which proves the best 
 soil for other crops. 
 
 A good balance in a soil thus depending not 
 on the total quantity of organic matter, but on 
 its eqwd distribution, a method of ascertaining 
 the relative character of soil in this respect was 
 worked out, and suggested, viz., estimating the 
 quantity of organic matter in that portion of 
 the soil that passes a sieve of 100 meshes per 
 linear inch, and regarding that quantity as a 
 " standard " for comparison ; estimating then 
 the organic matter in each of, say, six proportions 
 of soil that fail to pass sieves gradually increased 
 in size of openings from 100 to 10 meshes per 
 inch ; comparison of these, with the " standard " 
 should not show a variation in organic matter of 
 more than one-fourth on either side. Thus a soil 
 containing 12 per cent, of organic matter in the 
 portion that passed 100 meshes per inch should 
 show no variation in each of the six rougher pro- 
 portions beyond 9 to 15 per cent. It has been 
 found that soils which are most satisfactory in 
 "clover cultivation agreed in this respect ; that 
 other soils varying slightly were more or less 
 defective in clover growth, and that one soil 
 that absolutely refused to grow clover went 
 beyond these extremes in regard to no less than 
 61 per cent, of the rougher parts. It is suggested, 
 in order to bring out the requisite balance in 
 soil, that mechanical analyses of soil should be 
 made in such a way as to show (1) the proportion 
 that fails to pass a sieve of 20 meshes to the inch 
 — ^put as gravel or stones ; (2) the proportion .that 
 passes 20 meshes and fails to pass 100 meshes, 
 and the organic matter associated with inter- 
 mediate sizes, which shotdd not vary more tjian 
 
86 
 
 one-fourth on either side of the " standard " 
 given by No. 3 ; (3) the proportion that passes 
 100 meshes and its organic matter which is taken 
 as a "standard" for comparison; (4) the 
 proportion suspended in water after agitation 
 and rest for one minute, and its organic matter, 
 which should be about double the proportion of 
 No. 3. 
 
 The practical value of this inquiry Ues in 
 possession of the knowledge of the cause of 
 failure of clover and similar plants in soil other- 
 wise satisfactory. A knowledge of the cause is 
 the surest guide to remedy. The remedy, how- 
 ever, may be impractical with profit, for, to render 
 cohesive a soil that is not cohesive enough is 
 likely to be a costly and laborious matter. But, 
 knowing the cause, rational efforts are suggested, 
 such as frequent rolhng, especially preceding the 
 usual periods of drought and frost ; dung is not 
 likely to improve as not imparting cohesion (the 
 soil is often already too organic) ; but ploughing- 
 in green crop, which contains cohesive matter 
 (starch, gum, &c.), might efiect the purpose, 
 such as rye grain sown in autumn and ploughed 
 in at spring; also, potash manures by reducing 
 to a soluble form the organic matter of soil, may 
 be expected to remedy, and in practice has been 
 found to effect improvement. In any case the 
 mystery as to the cause seems removed. 
 
 (5) SBLl'-CROSS rBBTILISATION Off OBEEALS AND 
 GBASSES. 
 
 As the result of four years' trials by this 
 Association it was found that if two varieties of 
 oats, ripening at the same time, are sown in lines 
 side by side, or otherwise closely sown, they 
 cross-fertilise one another, and the greater vigour 
 thus imparted to the seed is such that, when 
 sown in the following year, the produce is in- 
 creased by about 24 per cent. 
 
 Some botanists have opposed this doctrine ; 
 one or two have been conspicuous in opposition. 
 In the interest of truth, and of progress of 
 science, their method should be exposed. They 
 do not seem to have realised the position into 
 which they were thus putting themselves. 
 Actually, in their zeal to oppose, they entrapped 
 themselves, for, in supposing they were opposing 
 the Association, they were actually (and pro- 
 bably unknowingly) opposing an established 
 doctrine — ^a doctrine accepted by all agricultural 
 bptanists, and also opposing one who is recognised 
 
87 
 
 as perhaps the greatest authority on the subject 
 of crossing plants, viz. Darwin. 
 
 What the opposition has said, in order to 
 disparage the Association's discovery, is — that 
 in cereals and grasses (he ovary is fertilised 
 before the flower has opened, and hence, that 
 self-cross fertilisation cannot take place. To 
 show that this is directly opposed to accepted 
 doctrine, it may suffice to quote from one of 
 the most advanced of Agricultural Botanists 
 — ^viz., Professor Kerner of Vienna who, in his 
 elaborate work. The Natural History of Plants 
 (which has been translated into English by Prof. 
 OUver, and goes more deeply and thoroughly 
 into Agricultural Botany than any British 
 work), definitely lays down, not as a new but 
 as a well understood fact, that grasses and 
 cereals are " wind fertilised" i.e. that the pollen 
 of one plant is conveyed by wind to the ovary 
 of another plant and fertilises it, and therefore, 
 of course, that the ovary is not fertilised before 
 opening. This has never been questioned. 
 Further, Darwin, basing on direct observation 
 of wheat, emphatically states that the ovary is 
 not fertilised before opening, but is fertilised by 
 pollen from other plants. The question then is 
 — does the bitter little opposition accept this, 
 or does it not t Bound to accept, it will probably 
 leap to this conclusion — then it was known 
 before, and the Association has merely oonfirmed 
 what was known. One thing at a time. The 
 first tiling to note, in the interest of sacred 
 truth and advance, is — that the opposition 
 dared to assert to the uninitiated as a truth 
 what either they knew to be an untruth, or 
 (if ignorant of the accepted fact of " wind 
 fertilisation ") they must have known was based 
 on doubtful evidence ; therefore to advance it 
 to the uninitiated firmly as a truth, and to do 
 this in the face of actual trials that ought to 
 have deepened the doubt, was such a deviation 
 from rectitude as should cause them to retire 
 in shame from this discussion. There need 
 be no doubt then that the admitted doctrine 
 is that cereals are " wind-fertilised." 
 
 It may now be stated what advance was 
 really sought by the Association. It was this : 
 — Knowing (1) that oat plants of one variety 
 growing in a field are fertilised by one another 
 by conveyance of pollen by wind ; knowing 
 (2) that by the artificial plan of castration and 
 dusting on the stigma some pollen of another 
 variety crossing takes place ; and knowing 
 
88 
 
 (3) that plants tend, and even prefer, to cross- 
 fertilise with another variety, and that greater 
 vigour and greater produce result from such 
 crossing — ^knowing all this — ^the question was : 
 Would it be possible without castration (beyond 
 the skill of the farmer), but merely by mixing 
 and sowing two varieties side by side, to secure 
 such crossing, and thus secure greater produce 
 with no trouble and no outlay ? That was the 
 new question put by the Association, and that 
 was the advance sought. The practical value 
 was that if this were possible, farmers might 
 secure the benefit on the large scale by simply 
 mixing seeds of two varieties that ripen at 
 the same time, sowing them, and preserving 
 the more Or less crossed seed thus produced, 
 to be sown in the following year, when the 
 increased vigour might be expected to give 
 increased produce. 
 
 Numerous trials were made extending over 
 four years. The results were most satisfactory ; 
 crossing undoubtedly took place, and frequently 
 to a large extent, the extent apparently varying 
 accordingly as the two varieties happened to ripen 
 at the same time, a difference of two or three 
 days might have a marked effect. The crossing 
 was shown by the different forms and colours 
 produced ; for instance, black oats crossed with 
 white oats assumed a brownish or tawny colour ; 
 varieties having flower heads branching hori- 
 zontalh/ on all sides of the stalk, crossed with 
 varieties branching erectly and only on one side, 
 produced » flower head differing from both of 
 them, showing sometimes dense clusters, some- 
 times the one-sided form changed to all-sided, 
 and vice versa i usually several intermediate 
 forms were produced, while long narrow grains 
 were changed to shorter, plump grains, &c. 
 Not only so, but the plants were more vigorous 
 and more productive (and occasionally ripened 
 earlier), the average greater yield in the first 
 year of the trials being 24 per cent., in the second 
 year 32 per cent., in the third year 16 per cent., 
 or an average increase over the three years of 24 
 per cent, by this simple process which mm/ he 
 easily adopted in practice. It thus appears 
 evident that while farmers may no doubt increase 
 their produce by the purchase of seeds carefully 
 crossed artificially (Which are costly), they may 
 also, and without cost, arrange their sowing 
 so that self-crossing will go on naturally, and 
 the resulting seed will give greater production 
 varying according to his success in the selection 
 
89 
 
 of the two varieties. The main precautions 
 being (1) to select two -vaneties diatiiictly different 
 from one another, and (2), and especially, to 
 select varieties that ripen at the same time. 
 
 (6) METHOD OF EBPBODTJCTION IN 
 CBBEALS AND GRASSES. 
 
 It was most natural that the conclusion should 
 have been leapt to, that the two feathery-like 
 structures in the flower of cereals and grasses, 
 standing as they do usually on the head of the 
 ovary, must be a part of the fennale organ, and it 
 does not appear to have arisen in the mind even 
 to doubt it. Yet any one who microscopically 
 examines these structures will at once recognise 
 that they are quite unfitted for the passage of 
 the pollen tube, whereas in plants generally 
 the stigmatic arrangements are well adapted 
 for that purpose. Kerner recognises the diffi- 
 culty, and seems struck by it, remarking that 
 " the pollen must often execute complicated 
 curves, or grow spirally." Further, no one 
 appears to have followed, or discerned a single 
 pollen tube, or its remains, passing down to the 
 ovary by this route. The cross-fertilisation 
 investigations suggested a rigorous inquiry into 
 the matter. Numerous examinations were 
 made, and while pollen were often seen lying 
 on the feathery-like structures, and frequently 
 were seen to send out a tube, yet the tube was 
 never found to penetrate down the feather, but 
 died in making the attempt, after traversing 
 (mostly about the outside) only a small fraction 
 of its length. The fact of the structures being 
 regarded as the stigma, taken in conjunction 
 with the other fact, that the feathers are often 
 lirrvp and useless, and therefore have evidently 
 already performed their function, before the flower 
 opens, would easily lead to the erroneous assump- 
 tion that fertilisation is over before the flower 
 opens. But the inability of the feathers to 
 convey the pollen led to the discovery by this 
 Association that the two feathery structures 
 which (merely for convenience of carrying out 
 their function) are settled (usually but not 
 always) on the head of the ovary, are really 
 rigid brushes for driving out the anthers, in order 
 that the pollen may be scattered outside, and 
 be borne ofi by the wind to carry on fertilisation 
 on another plant of the same, or of a different 
 variety. The brushes have been seen frequently 
 in such position, and under such condition as 
 
90 
 
 tb show that they are performing this function, 
 which their rigidity and their projections 
 eminently fit them to do, while their dense and 
 traverse structure, and their frequent dying 
 condition when the flower opens to receive 
 poUen, show that they are not intended to 
 transmit the pollen tube. 
 
 If, then, the feathery structures are not stigmas, 
 the question arose — ^Where is the Stigma ? In 
 other words, where do we find pollen grains 
 settling and successfully sending their tube into 
 the heart of the ovary ? It was found that the 
 viscid head of the ovary is itself the stigma ; that 
 when the ovary reaches the receptive stage, it 
 changes from a small oval body to a larger 
 pear-shaped body, broad end upwards (which 
 altered form assists the opening of the flower), 
 while the head is covered with hairs spread out 
 in fan-hke form, an arrangement which serves 
 — aided by the viscidity of the ovary head — to 
 catch and retain the pollen. The pollen tube 
 has actually been observed, in various stages, 
 penetrating the ovary and passing into the 
 mioropyle of the ovule. 
 
 It has thus been found (I) that the anthers 
 are ripe, and are usually more or less completely 
 projected from the flower before the ovary is in 
 aptitude for impregnation, and that the anthers 
 shed the greater part of, and frequently all, 
 their pollen outside the flower ; (2) that the 
 two feathery-Uke structures in the cereals and 
 the grasses, usually called stigmas, perform no 
 stigmatic action, but are brushes for the purpose 
 of forcing the anthers outside the flower before 
 it opens ; (3) that the real stigma is the blunt 
 head of the ovary ; (4) that the impregnation 
 condition is determined, not by the ripeness of 
 the male organ, but by the ripeness or reoeptive- 
 ness of the female organ ; (5) that when the 
 female organ is in fit receptive condition, the 
 flower Opens to receive foreign pollen ; (6) that 
 each grain of pollen contains numerous rapidly 
 moving cells, probably ciUated ; (7) that all 
 the arrangements and operations of the flower 
 are admirably adapted for self-oross-fertilisation ; 
 and (8) that the poUen being ripe and shed (in 
 part at least) before the female organ is in 
 receptive condition, it foUows that external 
 fertilisation is the nile rather than the exception, 
 for impregnation cannot take place until that 
 organ is in a fit and receptive condition. One 
 may ask how long will it be before botanists 
 accept this esplanation ? Probably for yet 
 
91 
 
 another generation will their students be taught 
 that the Gramineee have two feathery stigmas. 
 
 (7) PLASTICITY (or LIABILITY TO CHANGE FORM) 
 01' BYB ORASS. 
 
 At least one-half of nearly every farm in the 
 north-east of Scotland is in grass, which is cut, 
 or pastured ; and the grass most esteemed, and 
 most depended upon in Scotland generally, is 
 rye grass {Loliura perenne). But general 
 regret is expressed that it diss out in two or three 
 years, and gives place to what is called " natural " 
 or uncultivated grasses, having an unsightly 
 appearance and a less nourishing character. 
 How to remedy this seemed a worthy investi- 
 gation. After many prolonged trials, and 
 numerous extensive observations, it was found 
 that rye grass does not really die out, as is 
 supposed, more readily than other grasses, but 
 that it grows so rapidly and forms so unusually 
 large a root extension, and thus so quickly 
 utilises the food in the soil, that its later re- 
 quirements are not provided, and hence it 
 degenerates into a form so different from rye 
 grass as not to be recognisable as rye grass by 
 farmers, nor even by botanists. Specimens 
 known to have originated from rye grass being 
 sent to three botanists to be named, were given 
 three different names, the nearest to the truth 
 being the one who saw a, resemblance to rye 
 grass. The broad leaves are changed to very 
 long narrow leaves, so rolled up as to resemble 
 a thin wire, and the flower head of sessile florets 
 is converted into a, branched panicle. Yet a 
 carefvil examination shows that it retains the 
 essential characters of rye grass, and also, that 
 if properly fed, it resumes its original form of 
 the leaves, though the flower is not so quickly 
 reproduced. Numerous plots with different 
 grasses were grown both in the north of Scotland 
 and in the south of England, and it was found, 
 in every case, that only in the rye grass plots 
 did this degenerated form appear. !Frequent 
 trials and numerous examinations have served 
 to confirm this conclusion, as well as many 
 observations on the smaU and large scale. One 
 may be mentioned which all can verify. Let a 
 field of pasture be selected which is known to 
 have been sown with rye grass, but which has 
 been allowed to lie so long in pasture that 
 all trace of rye grass seems gone, and 
 only what seems " natural " grasses remain j 
 
92 
 
 but, if the green patches resulting from cattle 
 excrement be carefully examined, it will almost 
 certainly be found that, with the greater nourish- 
 ment, much of the wiry grass has assumed the 
 broad leaf of rye grass, with its corded surface, 
 its glossy one-ribbed back, uniform in breadth 
 till near the point, and reddish at the base, 
 while some true rye grass flowers may be seen. 
 
 An exceptional opportunity was afforded of 
 confirming the change of form, although it had 
 so often Deen proved that it was done more 
 for amusement than for proof. In the cleft of 
 a tree some small weeds were observed growing ; 
 it was a situation of course that provided ex- 
 ceedingly little nourishment, yet growth was 
 possible, and it was a situation that precluded 
 the presence of any plant except the seedling 
 weeds observed. All the vegetation was scraped 
 out, leaving only partiaUy decayed wood. 
 Some rye grass seeds were then sown. True 
 rye grass leaves were formed in the first year; 
 in the second 'year true rye grass leaves 
 and flowers were formed; in the third year 
 the results were the same, but the plants 
 were very small and emaciated ; in the 
 fourth and flfth years all the leaves became 
 of the very long wiry form above described, and 
 the flowers were all of the panicle form which 
 would not be recognised as rye grass. Yet 
 there cannot be the slightest doubt that they were 
 the original rye grass plants. Although it is 
 doubtfjii if, in this exceptional and cramped 
 situation, they would fully return to the original 
 state, yet it was attempted to do so by generous 
 treatment, as has frequently been done, so far 
 in soil trials, just as may often be seen in fields 
 on those spots where animal excrement had 
 been deposited. Dung was inserted in the 
 tree cleft — the leaves then assumed the broad 
 rye grass form and character, except that they 
 still were long, but the flowers continue as yet 
 to be branched. The change from this wild 
 or natural state to the cultivated form is com- 
 paratively quick, so far as the leaves are con- 
 cerned, but it takes longer for the flower to resume 
 the sessile cultivated form. How this should 
 be is not known, but it is possible that the sessile 
 flower of the cultivated form may be the result 
 of crossing. This, however, does not affect the 
 fact that rye grass changes — degenerates — by 
 poverty to this very different form, and may 
 be prevented from doing so by due provision of 
 food. 
 
93 
 
 The practical value lies in the information 
 to the farmer that he may, by manuring, retain 
 the esteemed rye grass in its natural form. 
 Bealising now that the change in the pasture 
 is not due to the limited life of the plant, hut to 
 poverty of soil, he is in a position to remedy the 
 defect. 
 
 The extraordinary form in the change of 
 the rye grass appears also to provide a 
 useful fact in connection with the evolution of 
 species, because it indicates a power of change 
 of form so great that the new form would 
 generally be regarded as a different variety 
 (it deceived two botanists to that extent), 
 whereas it appears to be only the reversion of 
 a cultivated plant to the original uncultivated 
 form, and thus gives evidence of the power of 
 living things greatly to change their form according 
 to the conditions in which they are placed, 
 without implying any change in its essential 
 specific features, or without justifying the idea 
 that one species, either gradually, or by a leap, 
 changes of itself into another species. 
 
 (8) BEDT7CTI0N OF MTNEBALS ESSENTIAL TO 
 PLANTS. 
 
 The reduction indicated in the number of 
 minerals absolutely essential to plants refprs 
 to the rejection from the Ust of chlorine and 
 sulphur. It is not claimed that the Aberdeen- 
 shire experiments have dealt specially with 
 chlorine, but merely that, in the distiUed-water- 
 culture trials, no chlorides as a rule were used, 
 but salts free from chlorine, and 5 that the 
 absence of chlorine never appeared to afiect 
 the ^owth. If, therefore, chlorine isTessential, 
 it must be only as an infinitesimal' trace, and 
 there is reason to doubt the accuracy of/placing 
 it among the essentials — while it appears little 
 more than an assumption that it is essential 
 to the formation of chlorophyll. 
 
 In regard to sulphur, however, the information 
 is more definite, inasmuch aa, in various trials, 
 large and healthy turnips were grown in sand 
 which contained practically no sulphur (merely 
 slight traces of it), and to which no sulphur was 
 given. Yet the plants grew well, and they 
 contained only faint traces of sulphur, ^nd ulti- 
 mately one plant was grown in which no trace 
 
94 
 
 of sulphui could be detected. Now the turnip 
 is a plant that might be expected more than 
 most others to require sulphur, but its absence 
 did not appear to affect its growth in any way, 
 a ftilly developed and healthy plant being pro- 
 duced without it. Against this view it may be 
 argued that albumen always contains sulphur, 
 but doubt arises in regard to this idea, owing to 
 the well-known difficulty of obtaining absolutely 
 pure albumen ; its constitution cannot be said 
 to be regarded as settled, and its glutinous 
 character is such that sulphur may well be an 
 accidental impurity. Phosphorus at one time 
 was in the same way supposed to be'^also a con- 
 stituent of albumen, but many, with perhaps 
 less reason, now regard its presence as acci- 
 dental, owing to the same glutinous character 
 of albumen and the difficulty of separating it 
 in absolutely pure form. 
 
 The mineral (or solid soil) elements essential 
 to plants are thus reduced to four in number, 
 viz. two that are dominant, phosphorus and 
 potassium, and two that are subordinate, 
 viz. calcium and magnesium. Here it may 
 be useful to briefly indicate the source and 
 general features in regard to plant life of these, 
 and the other essential elements, so far as 
 Agricultiiral Science has ascertained : — 
 
 Source. Element. 
 
 1\ provided by water ; exist 
 
 Hydrogen I in plant chiefly as water ; 
 
 Oxygen [ and largely as water 
 
 I united with carbon. 
 
 /Carbon provided by the gas oar- 
 
 I bonic oxide in air — ab- 
 
 Aj / aorbed, and decomposed 
 
 into carbon (retained) and 
 
 oxygen (rejected). 
 
 ifitrogen provided by the gas 
 
 nitrogen in air, absorbed 
 
 by special organs and 
 
 assimilated ; and by 
 
 nitrates and ammonia 
 
 in soil, when present. 
 
 Witi 
 
 Soil 
 
 lS^gn™um }i°toectly useful 
 
 The first four, i.e. the atmospheric elements, 
 constitute about 99 per cent, offplants, thus 
 leaving only about 1 per cent, to'be provided 
 
9S 
 
 by elements in soil, which is thus largely — not a 
 pro'Hder of food, but a conveyer of food ; the 
 differences in soil are largely due to their vary- 
 ing fitness to convey suitably. 
 
 (9) THE DIBBOT UTIUSATION OF NITROOBN IN 
 AIB BY PLANTS. 
 
 No question in Agricultural Science haa ex- 
 ercised the minds of soientiflo men more, and 
 no question is deemed of more importance in 
 Agricultural Science than the means by which 
 plants obtain their nitrogen. That element is 
 an essential constituent of the most dominant sub- 
 stance in all living things, viz. albumen. Prom 
 this fact alone it may be premised that, in one 
 way or other, nature must ensure its due pro- 
 vision to plants. Considering that the atmos- 
 phere, which bathes plants constantly, is largely 
 composed of nitrogen, it would appear to be the 
 most natural source of provision, just as rain, 
 and dew, and invisible water vapour or gas, 
 provide water to plants, and just as carboaic 
 acid gas in air provides carbon to plants. 
 
 The careful experiments of the eminent French 
 chemist Boussingault, emphatically negatived, 
 however, the idea that plants can make use of 
 any nitrogen in the free, or uncombined, form 
 in which it exists in the atmosphere. And 
 though Ville — also a French chemist — by equally 
 careful trials (checked and certified as accurate 
 by the French Academy of Science) very effec- 
 tively demonstrated the reverse view, yet a 
 repetition by Boussingault of his trials appeared 
 to him to confirm his negation, and (largely from 
 his eminence and influence) his view became 
 generally accepted. This view was strengthened 
 by trials at Rothamsted in England, which 
 seemed, at the time, to confirm its accuracy. 
 
 It is most curious how often truth is smothered 
 by influence and authority. Since that time — 
 over sixty years ago — the air has been sharply 
 excluded in the dogma of science from ability 
 to provide nitrogen to plants, and the activities 
 of plants have been put down as absolutely 
 unequal to fix it. From the soil alone, it has 
 been laid down, can plants derive any nitrogen. 
 And that idea has been maintained although 
 plants are bathed constantly in this nitrogen of 
 air, although they are greatly in need of nitrogen 
 to form their basic material, although the soil 
 often contains so Uttle nitrogen as to render it 
 very unfit to properly provide plants, although 
 
96 
 
 there is a special arrangement in soil to convert 
 what little it contains into a form that passes oS 
 quickly to the drainage system, and although, 
 finally, plants find no difficulty in utilising 
 carbonic acid gas in air to provide themselves 
 with carbon. Nature seemed to have made a 
 blunder in giving the soil, so uncertainly provided, 
 a monopoly in the supply of the ingredient that, 
 of all ingredients, might be regarded as most 
 essential to the life of plants, and about the 
 provision of which there should be no uncertainty. 
 But it may safely be said that nature never 
 makes a blunder, and the semblance of it in 
 regard to nitrogen now appears rather to be 
 actually a beneficent regulator suitable for the 
 life and growth of both animals and plants. 
 ! Undoubtedly, a certain quantity of nitrogen 
 is derived by plants from the soil, but facts were 
 constantly occurring in actual practice (such as 
 the production of heavy, and highly nitrogenous 
 crops of legumes, turnips, rape, &c., on soiL con- 
 taining little nitrogen, and this without reducing, 
 but actually increasing the nitrogen in the soil) 
 which demonstrated that at least certain plants 
 must acquire nitrogen from air. Liebig, while 
 feeling bound to accept Bouaaingault's negative 
 evidence, was yet satisfied from his direct 
 observations that, somehow or other, nitrogen 
 is really provided by the air. Shut out from 
 free nitrogen in air, he concluded that it must 
 be provided in the combined form of nitrogen, 
 viz. ammonia, and, as the exaggerated quantity 
 of ammonia at that time supposed to be in air 
 seemed sufficient for the purpose, he adhered to 
 this view, which, however, is now known to be 
 untenable, because it has been definitely proved 
 that all the combined nitrogen in air in various 
 forms (ammonia and nitric acid) does not amount 
 to more than 5 lb. falling on one acre per year, 
 and as crops frequently contain ten times fl-s 
 much, and as these crops are carried out without 
 sensibly lowering the nitrogen of the soil, it 
 became evident that this combined form of 
 nitrogen in air was far from solving the problem. 
 Yet the conviction of so shrewd an observer as 
 Liebig, that, somehow or other, the plants get 
 nitrogen from the air, is significant. He judged 
 from cultivated crops, but much stronger, and 
 even more obvious evidence is also presented by 
 the growth on the large scale of mighty forest 
 trees on the poorest soil, and even on bare 
 fissures of rook, containing no nitrogen, or only 
 minute traces of it, while the forest trees contain 
 
97 
 
 large quantities of it. Still, there was no direct 
 scientific evidence of absorption of free nitrogen, 
 and no process or organ in plants could be 
 pointed to aa being concerned with such absorp- 
 tion, and hence, what had the semblance of 
 being direct scientific evidence of the contrary, 
 has sustained during all these years the doctrine 
 of non-absorption. 
 
 It is most remarkable on how slender evidence 
 a great doctrine may be based. Here we have 
 this outstanding doctrine based upon only one 
 system of trials by one man (Boussingault), and 
 even these were so ably opposed by trials by 
 another man (VUle) that the pro was as strong 
 as the con — the balance was equal. No doubt 
 Boussingault's evidence seemed, at the time, 
 to be confirmed by Lawes and his colleagues at 
 Eothamsted, but, as the method (with its now 
 apparent flaws) was identical in both caises, the 
 two trials may be regarded as constituting one 
 inquiry repeated by a second person. The 
 evidence was not only meagre, but doubtful, 
 because it was strongly contradicted, and, after 
 all, it was only negative evidence, i.e. absorption 
 had not been detected. 
 
 THifEELlABLB EVIDEKCE. 
 
 The failure to discover absorption, at once 
 suggests the question. Had the plants under 
 trial an opportunity of absorbing ? Assuredly 
 they had not an opportunity. The fact is well 
 known, and admitted, that the conditions of 
 Boussingault's and of LaWes' trials were quite 
 unnatural, and the results proved that they were 
 quite unsuitable. The arrangements were entirely 
 artificial, the" soil was ignited, the plants were 
 closely confined under glass, air was passed in 
 through acid, the needful carbonic acid was 
 artificially supplied, light, heat, and drainage 
 were artificially regulated. Now, if under these 
 conditions, vigorous, fully developed and average 
 sized plants had been grown, conclusions from 
 them might have been acceptable, for such 
 success would have shown that the artificial 
 arrangements were suitable and equal to the 
 natural conditions. But the actual fact is 
 (although it is not nearly so well known) that 
 the plants were quite abnormal, or " atrophied " 
 as Franck called them, as shown not only by 
 their exceptionally small size ( Jrd to ^Hth part of 
 a fair-sized plant), but by the admitted facts that 
 they were weakly, diseased, sometimes unto 
 S 
 
98 
 
 death, and that those that survived were only 
 partiaUt/ devdoped, failing as a rule to develop 
 seeds, but only empty seed heads, and such seeds 
 as were formed were shrivelled up or milky. 
 In short, they were such plants as, in modern 
 trials, are unhesitatingly thrown aside as worthless 
 and misleading. Such plants could not be 
 regarded as fit to do, or to show, what vigorous 
 and healthy plants could do. The unnatural 
 conditions were such as to render vigorous and 
 healthy growth impossible, for it has now been 
 found, by Franok and others, that only under 
 vigorous growth of the young plant are the 
 powers of the plant developed in such a way as 
 to absorb nitrogen. 
 
 These characters should have been sufficient 
 to put aside long ago the negative evidence of 
 Boussingault and Lawes as altogether in- 
 acceptable, and to leave the question of absorp- 
 tion or non-abaorption still open, but the hold 
 that an accepted idea gets, makes its removal 
 difficult. Thus Franck of Germany, Atwater 
 of America, and the author, had each pointed 
 out the inacceptable character the trials upon 
 which the doctrine wholly depended, but so 
 firmly established in the minds of all was the 
 doctrine of non-absorption, that exposiire of 
 the faulty character of the trials had little effect 
 in removing it. 
 
 Another weakening feature of these trials is 
 this — that not only were the plants deprived of 
 any opportunity of absorbing nitrogen, but 
 the plants chosen were mostly just of the class 
 (cereals) whose power of absorption even in the 
 healthy state now turns out to be exceptionally low. 
 It seems incredible that upon these faulty 
 trials alone so important a doctrine could have 
 been based as the inability of plants tojutilise the 
 free nitrogen of air. We all accepted^ it, aiid 
 only now do we see the explanation of our too 
 ready acceptance, viz. that while the figures 
 of the analyses were in the foreground, the 
 characters of the plants were in the background. 
 The latter certainly were not hid, they were even 
 specially referred to ; but they were explained 
 away as immaterial, and hence the vitiating 
 features gradually went out of eight. Now, 
 however, when opposing facts cause them 
 to be brought into full view, we have reason 
 to be somewhat ashamed of our very faulty 
 scrutiny. 
 
99 
 
 We come now to the giadual steps towards 
 the truth. Atwater of America showed that 
 legumes acquired nitrogen ; Franck of Gerinany 
 confirmed this, and showed that algse also 
 absorbed nitrogen ; Helhiegel in Germany also 
 confirmed the absorption of nitrogen by legumes, 
 but he, rather rashly, ventured to go much 
 farther by advancing the ideas (they were no 
 more) (1) that the well-known tubercles on the 
 roots of legumes are filled with bacteria ; (2) 
 that these bacteria absorb nitrogen from the 
 air ; (3) that the nitrogen is passed on to the 
 legumes on which they themselves Uve, thus 
 presenting a mutual benefit or " symbiotic " 
 action, an idea which, from its somewhat novel 
 and pleasing nature, " caught on." Actually, 
 however, it was never proved that the particles 
 were bacteria — they had characters distinctly 
 differing from bacteria — and very soon the 
 name was changed to bacterioids — or particles 
 like, or supposed to be, bacteria. Of course 
 bacteria would ultimately appear as they do 
 in all decomposition. Actually, also, no proof 
 was given, and it has not since been proved, that 
 these particles really absorb nitrogen ; it was 
 a mere idea advanced to explain the facts that 
 the tubercles were rich in nitrogen, and that the 
 plant contained more nitrogen than could have 
 been derived from the soil. It is remarkable how 
 often what is advanced as an idea gradually 
 comes to be spoken of as a proved fact. It is.i 
 unnecessary here to enter on the prolonged 
 controversy that has taken place on this tubercle- 
 bacteria idea, which has been alternately 
 accepted and rejected by different inquirers. 
 It may suffice to say that recently no less than 
 four Continental investigators, Pf eiffer,Ehrenberg, 
 Kemy, and Thiele (several, if not aU, of whom 
 were believers in the idea, but recognised that 
 there was no real evidence of its accuracy), set 
 themselves laboriously to procure evidence by 
 direct trials, and that they have been obliged 
 to confess frankly that they have failed to find 
 any evidence, and to state — viewing aU that 
 has been done and pubhshed — that there does 
 not exist any evidence of absorption of nitrogen 
 by bacteria of any kind, " We have," frankly 
 says Dr. Thiele of Berlin, " merely built up 
 theories of which there are no proofs." 
 
 It is well to note here that, whether or not 
 bacteria absorb nitrogen, is a matter that does 
 
100 
 
 not touch the altogether different question^ 
 whether or not green plants directly ahsorb 
 nitrogen. Both operations might go on side by 
 side. All that is here advanced is — that of 
 absorption of nitrogen by bacteria there appears 
 to be no proof. 
 
 NBW INQUIBY. 
 
 It was during this controversy that the 
 Director of this Association took up the subject 
 Berionsly, being led to it by certain trials in 
 another inquiry which indicated very strongly, 
 what he had long suspected, that nitrogen of air 
 is directly acquired by plants generally. He 
 recognised that the negative trials by Boussingault 
 and Lawes must be put aside, and therefore 
 presented no deterrent, but rather an encourage- 
 ment to further inquiry. Cognisant of the 
 difficulties and uncertainties associated with 
 gravimetric chemical trials, he endeavoured in 
 the first place to find a solution from the botanical 
 side, which, if obtained, might then be confirmed 
 from the chemical side. To the preliminary line 
 of action then taken was largely due the success 
 that attended the inquiry. Conceiving that 
 the seat of absorption was most likely to be the 
 fresh young parts of plants freely exposed to air, 
 ■-.c, the leaves, and that on, or about, them 
 therefore was likely to be found any structure 
 or organ of absorption if it existed, the questions 
 were carefully considered — what are the most 
 likely plants, the most likely parts of the 
 leaves, and the most likely stages of growth, 
 at which such organs might be observed; 
 and he was thus fortunately led to commence, 
 not with a cultivated plant, but with a wild 
 plant. Had this not occurred, it is doubtful 
 if the discovery would have been made, for, 
 in the plants usually cultivated, the organs 
 are most likely to elude detection, unless 
 the search is pursued with the persistence 
 assured by the conviction from analogy that 
 they are certainly to be found, or with the 
 knowledge when and where they are to be 
 found. 
 
 BISCOVBEY OF ABSORBDTG DEGANS. 
 
 Happening many years to have carried out an 
 investigation on weeds, which included estima- 
 tion of their nitrogen contents, he recalled the 
 unusually large quantity of nitrogen in Spergvla 
 arvensis (corn spurrey or yarr), and therefore 
 
101 
 
 chose it for the first examination. The choice 
 was fortunate, for, highly nitrogenous as that 
 plant is, the nitrogen absorbers are both numerous 
 and conapicuous, and thus consistent with its 
 high nitrogen contents. Studded over as this 
 plant is with sticky hairs, he — like botanists 
 generally — regarded them as what are vaguely 
 called " glandular hairs " (to which no particular 
 function is ascribed), Now, however, by 
 specialised observation, they assumed a totally 
 new aspect. Rigorous microscopic examination, 
 and careful and varied chemical tests, brought 
 out that the hairs actually are absorbers of 
 nitrogen from air, transformers of it into albumen, 
 and conveyers of the albumen into the plant. 
 What held good in Spergula would, it seemed 
 likely, hold good in other plants ; and actual 
 examination showed that this was the ease, i.e. 
 that absorbers of nitrogen were found to occur, 
 in one form or another, on all phnts. Search 
 for them, though attended frequently with 
 failure ,at first, has, in every case, after per- 
 sistency, been followed by success in finding 
 them in one place or other, if not in the edges, 
 or back, or ribs of the leaf, then on the young 
 stalk, or the leaf scales, &c. So also, absolute 
 failure to find them on some plants, such as 
 legumes, was followed by success on searching 
 at a certain stage of growth, i.e., the leaves iust 
 as they emerge from the hudr — Plater on they dis- 
 appear, being absorbed into the leaf. The 
 organs have now been found on a large number 
 of the most unlikely plants (on which nothing 
 akin to glandular hairs had been recognised), 
 such as hard-leaved pines. In short, on no plant 
 as yet thoroughly examined has the search 
 been unsuccessful, and evidently therefore we 
 have here not an occasional occurrence (as in the 
 case of the so-called glandular hairs), but a 
 general occurrence to ensure the provision of 
 the substance most essential to life — viz. 
 nitrogen to form albumen. 
 
 This constant occurrence was a strong feature 
 in the evidence. Had it not been found, in one 
 form or other, on every plant examined, there 
 would have been a weakness in the chain of 
 evidence, more especially if the absence appUed 
 to a highly nitrogenous plant, such as any 
 legume ; and long and trying was the vain search 
 for it on legumes. Had a legume been chosen 
 first, as from its high nitrogen content it might 
 probably have been, the discovery would almost 
 certainly not have been made, and the investiga- 
 
102 
 
 tion would probably have been given up. At 
 last, on the edge of a leaf, a minute knob was 
 observed which wag unusual, and close examina- 
 tion brought out that it possessed the specific 
 characters of an absorber, but in this case sub- 
 merged in the fleshy leaf ; remains of numerous 
 similar structures altogether submerged were 
 then seen ; it thus appeared that the examination 
 must be made at an eaiUer stage. Seedlings 
 were therefore raised and examined, when, instead 
 of any difficulty in finding the absorbing organs, 
 they now appeared at once and in abundance, 
 standing up like a forest and in the usual typical 
 form. This event was one of the most convinc- 
 ing features in the progress of the work — ^it gave 
 confidence of being on the right track. 
 
 Those of the nitrogen absorbers that happen 
 to have been observed by botanists, have been 
 classed among glandular hairs, and little or no 
 further notice has been taken of them, and no 
 function was definitely ascribed to them. But, 
 on the other hand, plants that have no glandular 
 hairs bear the absorbers ; further, many of the 
 so-called glandular hairs are not nitrogen 
 absorbers, such as the odorous glandular hairs 
 on the moss rose. It will fall to botanists now 
 to limit glandular hairs to those that are not 
 nitrogen absorbers. 
 
 The nitrogen absorbers occur most usually on 
 the youngest leaves just as the bud is expanding, 
 or soon after. They are rarely so large as to be 
 visible by the naked eye, but they can frequently 
 be seen by a lens, though generally the aid of 
 the microscope is necessary. They have a 
 definite and special character, a general re- 
 semblance in structure, and frequent resemblance 
 in form, and although the form varies greatly in 
 different plants, the specialised character always 
 remains. The usual structure is a long blunt 
 projection divided into sections, like a finger 
 with its joints (as in Spergula), the lower 
 sections being at first (and for some time) 
 colourless, transparent, empty, and double 
 walled ; the highest section, whach is very often 
 distended into a bulb or club-head-like form 
 (as in legumes and geranium), is altogether 
 different in appearance and distinctive in 
 character from the lower sections, by containing 
 yellowish-green matter resembling ehlorophyU, 
 but probably differing from chlorophyll ; it is 
 the active and essential part of the organ, and 
 it shows very marked changes during its period 
 of activity or Hfe. This is to say — the highest 
 
103 
 
 section of these structures, and it alone, is at 
 first filled with this yellowish-green chlorophyll- 
 like matter, and, even when just fully formed, 
 it shows no presence of albumen by the usual 
 tests ; gradually, however, that Jtughest section, 
 and that section alone, becomes charged with 
 albumen, and ultimately is gorged with it ; the 
 albumen then passes down through the open 
 ends of the sections into the vascular system of 
 the plant. These absorbers are found in all 
 stages of growth in regard to albumen contents, 
 i.e. absent, filling, filled, gorged, and emptied ; 
 frequently (as in the poplar and sycamore) 
 they occur in groups, in which all these stages 
 can be observed at one glance according to the 
 varying age of the members of the group. Very 
 often (as in potato) there are two forms on one 
 plant, as if showing a reserve to ensure the 
 provision of nitrogen, just as in plants there is 
 frequently a, reserve method to secure repro- 
 duction (i.e. flowers and leaf buds, runners, &c.). 
 On cereals and grasses the arrangement at first 
 found was very rudimentary in form and 
 limited in extent, and bence in accordance with 
 what is found in practice ; thus legumes and, 
 turnips require little or no artificial nitrogenous 
 manure, and they are just among the plants that 
 are profusely provided with absorbers ; while 
 those plants sparsely provided with absorbers 
 (as cereals) are just those that demand the 
 assistance of artificial nitrogenous manures to 
 sedu-e the large growth required in cultivation. 
 So rudimentary was the arrangement in cereals 
 and grasses that it seemed surprising that they 
 could be provided with nitrogen sufficiently to 
 explain even the small growth frequently 
 experienced in poor soil, but recently a very 
 distinct and interesting arrangement tas been 
 found dn the cereals aiid grasses that ensures 
 the provision of a certain supply. This accord- 
 ance of the varying number of organs with the 
 well-known varying demands for artificial 
 nitrogen supplies, was anotJier strengthening 
 feature in the chain of evidence. 
 
 The absence of knowledge of i),ny organ for 
 the absolution of nitrogen is what has stood so 
 long iii tfie way of the recognition of nitrogen 
 absorption by plants. It was there that Vule, 
 Franck, and Atwater fell short — being unable to 
 show how, or by what means, it was absorbed. 
 
104 
 
 Franok indeed predicted that sooner or later an 
 absorbing organ would be found. The dis- 
 covery now made of the existence of these 
 organs, not merely on many plants, but on 
 eviry plant examined, forms the conspicuous 
 feature of the solution now provided. 
 
 CONFIKMATION BY GEAWMBTBIO TBIALS. 
 
 There was thus already presented two-fold 
 evidence of the direct absorption of nitrogen by 
 plants, i.e. (1) constant experience in practice, 
 frequent experience in experiment, and general 
 observations in nature — especially by growth on 
 the large scale, such as forests, &c., on sterile soil ; 
 and (2) the discovery of the organs of absorption 
 as proved by microscopic observation of their 
 structure, their character, their gradual forma- 
 tion of albumen, and their discharge of it into 
 the plant, as well as by their presence on plants, 
 not occasionally, but generally, and in numbers 
 according with the demands for nitrogenous 
 manure in practice. 
 
 It was then endeavoured to find three-fold 
 proof by framing trials of a kind fitted to bring 
 out an increased weight of nitrogen that could 
 have no other source than the air. The diffi- 
 culties of doing so are well known. They are 
 due largely to the comparatively small quantity 
 of albumen in plants ; to the small proportion of 
 nitrogen in albumen ; to the comparatively 
 large quantity of nitrogen that, in one form or 
 other, exists in the best medium (the soil) in 
 which plants can, as a rule, be grown naturally ; 
 and to the need, in order to secure absolute, or 
 scientific, accuracy, to work on a small scale 
 of plant growth. Under these circumstances 
 it would hardly be possible to get reliable weight 
 results were it not for the fact that chemical 
 analysis can determine nitrogen to a quantity 
 so low as -'002 gramme and even less by certain 
 processes. This abiUty, along with consideration, 
 care, and conscientiousness, should be, and 
 have been found to be, sufficient to overcome 
 the difficulties. 
 
 Carefully considered trials were made with 
 scrupulous attention to avoid error, and repeated 
 frequently to check any error, by growing single 
 plants in specially purified distilled water, and 
 
1G5 
 
 also by growing a few plants in glass vessels 
 containing specially exhausted soil in which 
 the nitrogen had been most carefully determined. 
 To these media were added only pure chemical 
 salts of known composition, the exact nitrogen 
 contained being charged in the final balance. 
 The watering with distilled water was regulated 
 and registered, any fallen leaves collected, the 
 drainage reserved, and all tested for nitrogen 
 which was credited or debited, as the case might 
 be, in the final balanc^. The operations were thus 
 under the strictest controL That the conditions 
 of growth were satisfactory was shown by the 
 healthy growth, and by the fully developed 
 plants produced — leaves, flower, and seed. The 
 weight of produce was necessarily restricted 
 in the trials of the first year (Nos. 1 to 6) by 
 the small number of the plants that could be 
 grown in a glass vessel containing only IJ lb. 
 of soil, in the case of Nos. 1 to 4 ; and by the 
 nature of the plants grown in Nos. 5 and 6, 
 which even in the fully developed plants are 
 naturally small, and appreciable weight was 
 possible only by the large number of plants 
 produced. But while in this latter group (Nos. 
 5 and 6) the same strict control was observed, 
 the growth was unrestricted and entirely 
 natural, as it consisted of aqiiatic plants grown 
 in distilled water contained in large glass vessels, 
 which were placed in a loose-paned glass (Wardian) 
 case, enclosed in a glass house, and therefore 
 doubly protected from dust or other accidental 
 matter. A small quantity of piue chemical 
 salts was added containing no nitrogen, so that 
 this group of plants grew under the conditions 
 of total absence of nitrogen except the very in- 
 finitesimal trace in specially distilled water 
 (which was charged in the balance account), and 
 except what was at command from the air. 
 
 The results were that in the former, or soil, 
 group (Nos. 1, 2, 3, and 4) a distinct gain was 
 found in each case, small in quantity (as was 
 bound to be the case, by deaUng with few plants) 
 but large relatively, and such as accounted for 
 more than aU the nitrogen in the plants, and that 
 proportion was the normal quantity present 
 in the plants grown in nature. In the latter, 
 or water group, in which there was no restriction, 
 and in which the natural conditions were fully 
 complied with, the plants grew vigorously, and 
 reproduced by budding most profusely, and 
 thus demonstrated clearly by their very growth 
 alone, i.e. without any analysis, that they were 
 
106 
 
 deriving nitrogen from the air, because plants 
 cannot possibly grow without albumen formation. 
 Actual analyses, however^ proved the gain very 
 distinctly ; relatively to the amount provided, 
 it was very large, being no less than eighteen 
 limes higher than the nitrogen originally present. 
 In the following year it was attempted, and 
 with success, to secure gain of a aubatantial 
 weight of nitrogen, by using, in another set of 
 trials (Nos. 7, 8, and 9), large quantities of the 
 same thoroughly exhausted soil. It was placed 
 in large flower pots, 12 inches in diameter, iji- 
 serted in similar pots, glazed inside, and using 
 the same precautions as on the small scale. By 
 this now unrestricted growth, several large and 
 vigorous plants were produced under the most 
 natural conditions consistent with control, and 
 a gain of nitrogen now very substantial was found, 
 that could not have any other source than the 
 nitrogen of the air. The following summarised 
 table gives the results : — 
 
 ACTUAL GAIN OP NITROGEN FROM AIR. 
 
 
 
 Actual Weight of 
 
 
 
 
 Ratio 
 
 Gain of 
 Nitro- 
 gen in 
 
 100 
 parts 
 
 Dry 
 Plant. 
 
 
 
 Plants Grown. 
 
 Nitro- 
 
 Nitro- 
 
 Nitro- 
 
 ol Gain. 
 
 No. 
 
 Plants 
 
 
 gen Pro- 
 vided 
 
 gen 
 Found 
 
 gen 
 Gained 
 
 Nitro- 
 
 
 
 Grown. 
 
 Fresh 
 
 
 (in Seed, 
 
 (in Plants 
 
 (in Plants 
 
 
 
 Weight 
 
 Dry 
 
 Soil, or 
 
 •and 
 
 and 
 
 con- 
 
 
 
 (80% 
 
 Weight. 
 
 Manure). 
 
 Soil). 
 
 Soil). 
 
 sidered 
 
 
 
 
 Water. 
 
 
 
 
 
 as 100. 
 
 
 
 Grms. 
 
 Orms. 
 
 Grms. 
 
 Grms. 
 
 Grms. 
 
 
 Grms. 
 
 1. 
 
 Rape 
 
 20-20 
 
 4-04 
 
 1-32P0 
 
 1-4408 
 
 --1206 
 
 109 
 
 --643 
 
 2. 
 
 Cress 
 
 15-08 
 
 301 
 
 1-3198 
 
 1-4286 
 
 -•1088 
 
 108 
 
 1-285 
 
 3. 
 
 Stellaria . . 
 
 16-14 
 
 3-02 
 
 --1276 
 
 --1440 
 
 --0164 
 
 112 
 
 1-205 
 
 4. 
 
 Mimuliis . . 
 
 19-63 
 
 3-90 
 
 --1276 
 
 --1429 
 
 -0153 
 
 112 
 
 1-282 
 
 6. 
 
 Hydrocharis 
 
 1-90 
 
 --38 
 
 --0012 
 
 -■0092 
 
 --0080 
 
 790 
 
 1-666 
 
 6. 
 
 Azolla 
 
 6-65 
 
 1-38 
 
 --0014 
 
 --0263 
 
 -0249 
 
 1846 
 
 1-836 
 
 7. 
 
 Potato 
 
 664- 
 
 112-80 
 
 27-2697 
 
 33-0667 
 
 6-7960 
 
 121 
 
 1-080 
 
 8. 
 
 Beet 
 rPetunia ^ 
 
 438- 
 
 87-00 
 
 26-4280 
 
 27-0667 
 
 1-6277 
 
 106 
 
 1-670 
 
 9. 
 
 -( Geranium V 
 |,Tobaoco J 
 
 200-25 
 
 40-05 
 
 26-4799 
 
 29-6668 
 
 4-1769 
 
 116 
 
 2-088 
 
 In addition to the gain in the plant (stated 
 in the last column) there was a gain (included 
 in column 7) also to the soil in every case, except 
 in two cases which seem explainable. 
 
 The gains in the first six tiials may be con- 
 sidered small, so small as maj? appfear to Weaken 
 their value. Only the Uniriitiated, however, 
 would form this idea, and, to dispel it, the follow- 
 ing facts may bestated. (1) Essential as nitrogen 
 
107 
 
 is to plants, they contain very little of it ; in 
 the fresh state plants do not as a rule contain 
 more than --2 to --4 per cent, nitrogen, so that 
 in a, plant of 1 gramme weight there would be 
 present only --002 to --004 gramme nitrogen; if 
 the plant weighed 20 grammes (which is nearly 
 what the plants in the trials Nos. 1 to 4 weighed) 
 there would be only from --04 to -'08 gramme 
 nitrogen. Now the actual gains were --1088 and 
 -■1026 respectively, or twice the quantity actually 
 required to provide all the wanti of the plant grown, 
 the excess being passed into the soil. (2) The gain 
 of nitrogen in 100 parts of the dried plant, as 
 given in the last column, is in accordance gener- 
 ally with the nitrogen in the plants naturally 
 grown ; had it been greater the plants would have 
 been abnormally rich in nitrogen ; the air there- 
 fore provided all the nitrogen that the plants 
 required to form their albumen. 
 
 Any doubt that might remain, however, in 
 the minds of those not accustotued to deal with, 
 and consider, such small quantities, is entirely 
 dispelled by the trials Nos. 7, 8, and 9, in which 
 large quantities of plant matter were produced 
 and correspondingly large gains of nitrogen 
 were fotmd. Indeed it was largely to satisfy 
 the uninitiated that great pains were taken to 
 acquire a large actual weight of nitrogen from 
 the air, and although the difficulties of securing 
 aooiu-acy were increased. It was felt that, by the 
 very great care taken, they were entirely over- 
 come. The soil used was the same as formerly, 
 it had been exhausted for twenty years ; it 
 was partially dried, and then most intimately 
 mixed frequently, most carefully sampled during 
 mixing, and three times analysed before' and 
 after use, to ascertain the nitrogen contained, 
 and as these three analyses concorded very 
 closely, there is no reason for doubt that the 
 proportion of nitrogen in the soil Originally, 
 and in the soil at the end of the trials, was ac- 
 curately ascertained. Indeed, if there was 
 any error it would have been by soakage into 
 the flower pots, and this would have increased 
 the gain. By this arrangement, which provided 
 free root range, aeration, constancy of moisture, 
 and otherwise absolutely natural conditions, 
 the growth was vigorous and uninterrupted. 
 Every precaution was taken to debit the plant 
 with every trace of nitrogen given in watering, 
 &c., and to avoid disturbance as by algae growth, 
 dust, &o. The result, it will be seen by the 
 Table, is that not only was there a large relative 
 
108 
 
 gain as in the former cases, but a large actwil 
 gain of nitrogen, viz. from about 2 to nearly 6 
 grammes. 
 
 Trials Nos. 5 and 6 also deserve special at- 
 tention. They were aquatic plants, and being 
 grown in their suitable medium of water the 
 growth was very abundant. The actual weight 
 of nitrogen gained appears small, but actually 
 it is by far the largest relatively in the Ust, which 
 is due to the extraordinary multiphcation of these 
 small plants by a kind of budding action. AzoUa, 
 for instance, of which the few plants sown 
 covered only about an inch of surface, ultimately 
 completely covered and crowded the surface of 
 the vessel, which was about 20 inches in circumfer- 
 ence — the healthy flat green leaves being spread 
 out on the water, and played over continuously 
 by the air. Let it be remembered that nitrogen 
 was most carefully excluded from these vessels — 
 there was available only the faint trace that is 
 left in specially purified distilled water, and 
 the plants were debited with this infinitesimal 
 quantity. Now, when that trace was used up, 
 the plants should have died, unless they were 
 able to absorb nitrogen from air, because no 
 plant can possibly grow without the presence 
 and action of albumen. It is the essential 
 formative material within the plant. But 
 instead of dying they continued to grow vigorously 
 all the season, and hence, obviously, nitrogenotcs 
 albumen formation was going on freely, the 
 nitrogen for which could have no source but the 
 air, and actual analysis showed that tlie pro- 
 portion was such as exists in normal plants, 
 and that the gain was no less than eighteen times 
 the quantity originally present. If the quantity 
 originally present in the plants sown, along 
 with the trace in water, is put at 100, then the 
 quantity found at the end of the trial is no less 
 than 1846. 
 
 The evidence therefore seems satisfactory 
 and complete ; much more so than that on which 
 rests many of the doctrines confidently taught. 
 
 Full details of all the observations, methods, 
 and determinations are given in the Reports 
 of the Association (1905, 1906, and 1907). They 
 have been published and disseminated all over 
 
109 
 
 the world, and been under consideration tot 
 the past four years, and no weakening criticism 
 has been advanced ; on the contrary, congratu- 
 latory communications have been numerous. 
 
 The solution now provided accords with what 
 might safely be premised, viz. that Nature 
 would carefully ensure the provision of a substance 
 so essential to, and so dominant in, plants ; it 
 accords also with the obvious evidences from 
 growth in nature on a large scale (as forest on 
 sterile soils) as well as with frequent instances 
 of growth on the small scale, as in the case of 
 large plants frequently found growing in fissures 
 of rooks, crevices of walls, &o., which could 
 not — and which analysis show do not — contain 
 more than minute traces of nitrogen ; and 
 finally, it accords with the acceptance of cvdtiva- 
 tion in actual practice, while it dispels the 
 contradictions that were constantly appearing 
 under the former doctrine. 
 
 INDEPENDENT CONFIEMATION. 
 
 With this accordance, and with the structural 
 and physiological, and the chemical evidence, 
 the solution seems complete — the only weak 
 point being that they are the results of one 
 individual. Even this, happily, is met, for 
 most satisfactory, independent, and unexpected 
 confirmation came from the Continent. To the 
 author's pleasure and surprise (for he was unaware 
 that his discovery was being carefully tested), 
 a formal letter reached him signed by two Pro- 
 fessors of Botany in Hungary — Professors 
 Zempien and Both — that they had submitted 
 the discovery to rigorous scrutiny from the 
 Botanical side, in connection with forest trees, 
 that in every case, with one exception (now no 
 exception), the absorbing organs had been found, 
 and that the structure, the action, and results 
 of their tests distinctly confirmed absorption. 
 This is confirmation on the Botanical side. Later 
 on came confirmation on the Chemical side by very 
 rigorous gravimetric trials made by Professors 
 PoUacci and Mameli in Italy, which were made 
 the subject of a paper read by Professor Mameli 
 at the International Congress of Science in 
 London in May 1909. 
 
110 
 
 PRACTICAL VALUE. 
 
 It will be obvious that while the main value 
 of this discovery lies in its importance from the 
 scientific point of view, as providing a founda- 
 tional fact in Agricultural Science, yet it has also 
 a practical value. For, with the knowledge that 
 ptinia absorb nitrogen from air, and that different 
 plants vary in the power to absorb it, farmers 
 may take a variety of means to derive benefit by 
 lessening their purchases of nitrogenous manure, 
 and increasing their crops generally by increasing 
 the stock of available nitrogen in their soils. 
 They will, for instance, bo more distinctly guided 
 in the proportion of nitrogen necessary to give 
 as manure to different plants ; they will not 
 carry off the field matter which is useless (either for 
 sale or for feeding cattle), but which has absorbed 
 nitrogen largely from air, such as the stems and 
 leaves of potatoes and turnips ; they will intro- 
 duce clovers and other large nitrogen absorbers 
 much more freely in their pastures ; and specially, 
 they will endeavour to grow, in the intervals of 
 their rotation, some good nitrogen absorbers 
 suitable to the climate and soil, and plough in 
 the foliage before sowing their regmar crops 
 of grain. A number of trials, both in plots and 
 on the field on a large scale, have been made 
 to test the effect of such methods, and the ad- 
 vantage has been satisfactory, and sometimes 
 conspicuous. 
 
 ACCEPTANCE. 
 
 It is not to be expected that acceptance would 
 be sudden of a doctrine that reversed one that 
 had been confidently taught for so long «■ time. 
 " Science creeps but slowly," and we must be 
 satisfied with the happy absence of any refutation 
 of the evidence^ and with the independent con- 
 firmation of it, and patiently wait till the idiosyn- 
 crasies of human natm'e are overcome. 
 
 Nor need we be surprised that any opposition 
 (which has been almost entirely mere words or 
 evasions) has been rather from botanists than 
 chemists, when we recall the attitude of botanists 
 towards the absorption of carbonic acid of the 
 air by plants, from which plants derive their 
 immense quantity of carbon. Not a single 
 botanist Uves who does not now believe in this 
 doctrine. But what said Liebig in 1840, when 
 chemists had settled that fact ? In his Orgari/ic 
 Chemistry in its application to Agriculture and 
 Physiology, 1840, p. 26, he observes — " How does 
 
Hl- 
 
 it ha^ppeu, it may be asked, that the absorption 
 of carbon from the atmosphere by plants is 
 doubted by all botatiists and vegetable pliysio- 
 logiste, and that by the greater number the 
 puriflcation of the air by means of them is wholly 
 denied." If botanists denied so long this — at 
 that time — ^well proved fact, we need not be 
 surprised if they are similarly long in accepting 
 the absorption of nitrogen. 
 ' The fact is that botanists as a rule are not 
 chemists — they do not even pretend to know 
 chemistry well. Similarly, chemists as a rule 
 do not know botany well. The artificial division 
 of nature's work into branches, such as chemistry 
 and botany, has given rise to a field between 
 the two that has been too much neglected, and 
 any deduction by phemists regarding plants is 
 looked at askance % botanists as a kind of 
 intrusion on their field, and of suggesting some- 
 thing new which they might have peen expected 
 to find out, and on which they have formed and 
 taught another explanation. It will be to the credit 
 of botanists in these days of more free circulation 
 of work and thought not to lengthen the period, 
 of unfounded opposition to the absorption of 
 nitrogen, to the extent that they continued 
 their "unwarrantable opposition to the absorption 
 of carbonic acid. 
 
 But in the particular case of nitrogen ab- 
 sorption, botanists are not to be blamed, but 
 rather chemists, for the eminent botanists, Sachs 
 and Van Tieghem, each indicated that they 
 would have ascribed to these hairs the process 
 of nitrogen absorption, had it not been for 
 Boussingault's emphatic pronouncement that 
 plants did not absorb nitrogen. 
 
 CIECULATIONS IN NATTTBE OF MATTEK 
 CONNBOTBD WITH PLANT LIFE. 
 
 The r61e of nitrogen in connection with plant 
 ife being now ascertained, the three grand 
 circulations in nature of matter connected with 
 plant and animal life may now .be delineated. 
 The circulation of water and carbonic anhydride 
 in nature is well known, and that of nitrogen 
 now seems clear. In each of the three cases 
 the circuiation is deviated from in regard to a 
 proportion of the matter. Thus, much of the 
 rain water that falls on the earth goes directly 
 by evaporation back to the atmosphere, so also 
 much of the carbonic anhydride which goes into 
 plants passes directly back to the atmosphere 
 
112 
 
 when pUnt matter is burued or decomposed ; 
 and so also much of the nitrogen, by similar 
 decomposition, goes to the atmosphere in the 
 form of ammonia, or, in certain states of decom- 
 position, in the form of nitrogen. Further, the 
 natural circulation is interfered with by the 
 artificial arrangements caused by communities, 
 by which a part of the three materials goes in 
 the form of sewage to the sea, instead of passing, 
 as in the natural course, to the soil, and thence 
 by drains and rivers to the sea. Apart from 
 these deviations, the circulations are as shown 
 on the appended diagrams. 
 
 With regard to the nitrogen circulation, we 
 can now trace it direct from the air into plants, 
 forming albumen, which passes into animals, 
 and from both plants and animals into the soil, 
 and, being there met by lime and bacteria, is 
 changed into nitrate of lime, which passes into 
 the ^ains, thence to the rivers and sea. It is 
 not known what particular process takes place 
 in the sea, but we know that immense quantities 
 of nitrate of lime do pass by rivers into the sea, 
 for it is known that about 20 lb., or, in the case 
 of well-drained land, up to 60 lb. nitrogen per 
 acre per year is thus carried off in the drainage 
 system. Now the immense quantity of nitrate 
 thus delivered to the sea does not form any 
 deposit of nitrogen salts, nor is it contained to 
 any extent in the sea water, and, therefore, must 
 escape. We know also that living animals in 
 the sea inspire oxygen and expire carbonic 
 anhydride, and the latter, by action on the 
 nitrate of lime, would form (o) carbonate of lime 
 (of which shells, chalk, coral, &c., are composed), 
 and (J) nitric oxide ready by deoxidation (thus 
 providing oxygen for animal life) to become free 
 nitrogen, which, being almost insoluble in water, 
 must escape. Its escape to the air has not been 
 computed, but, that the escape is certain, seems 
 obvious from the facts of the disappearance 
 above stated, and this is confirmed by our actual 
 knowledge that nitrates in badly aerated soils 
 are reduced to nitrites, and that in water-logged 
 soils they are reduced to nitrogen gas, so that 
 in actual water, deoxidised by animal life, we 
 have the same condition for the production 
 of nitrogen gas. 
 
113 
 
 THE THREE GREAT CIRCULATIONS OF MATTER 
 IN NATURE CONNECTED WITH PLANT AND 
 ANIMAL LIFE. 
 
 Water 
 
 Dminaci 
 
 SOIL' 
 
 Plants 
 
 ftNIMAlS 
 
 ,filR 
 
 Carbonic 
 Anhydride qq 
 CO, 
 
 ■Nitrogen 
 N 
 
 Plauts 
 
 0, to air : 
 
 Animals 
 
 Aw. 
 
 Pi/tNrs 
 
 N Change^lo 
 
 Albumen 
 
 flNIMALS 
 
 -30IL' 
 
 LimetBacleria 
 
114 
 
 PRESENT WOEK OP THE ASSOCIATION. 
 
 Three investigations are proceeding which 
 have been going on more or less contijiuouBly 
 for several years. The most important one 
 has been on hand for about seven years and is 
 nearly completed, but the vrork is stagnated 
 for want of sufficient means, and although the 
 investigation will be completed, the costly 
 publication cannot be ventured upon. Yet it is 
 an investigation of a most interesting nature 
 from a scientific point of view, and one that 
 should have no little practical benefit. 
 
 PEOSPBCT OF PROGRESS. 
 
 The History of the Progress of Agricultural 
 Science in Great Britain has now been brought 
 up to the present time. At the present time 
 little is being done to advance Agricultural 
 Science ; practically nothing more than the 
 little that has been going on for the past genera- 
 tion. Consequent on State Grants to Agricul- 
 tural Colleges that have been established in 
 different parts of the country, much more field 
 experimental work is now done than formerly, 
 but it is educational rather than original, 
 illustrative of what is known rather than a search 
 for the unknown, in regard at least to any 
 foundational matter. 
 
 Quite recently, however, the State has provided 
 means for the development of Agricultural 
 Research, which is a signal step in advance 
 that gives grounds for the hope that the great 
 progress that is possible may now be made. So 
 far, however, as the steps already taken indicate, 
 it is to be lamented that there is serious cause 
 to doubt if the hope will be realised. Already, 
 so far as Agricultural Eesearoh* is concerned, 
 the movement seems to have run into a restricted 
 channel, under restricted guidance, which fore- 
 shadows misapplication, monc^oly, and personal 
 influence, instead of the free and capable develop- 
 ment that the subject demands. Independent, 
 disinterested, capable inquiry as to what is 
 really required seems likely to be dispensed 
 with ; individual investigators are not to be 
 dealt with ; the guarantee of past work is not to 
 be recognised ; and what seems imminent is 
 a mergence into a bureaucratic system which 
 will rely for the work to be done on collegiate 
 organisations, the governors of which are un- 
 
115 
 
 familiar with such work ; the work is to be 
 relegated by these official bodies to individuals 
 who, 80 far as their work in the past shows, are 
 interested in remuneration rather than in the 
 search for hidden truths ; all is to work like a 
 machine, constructed, regulated, and driven at 
 command, instead of under the special considera- 
 tions and arrangements necessary for this special 
 and Uttle known kind of work. 
 
 What will be the result can easily be foreseen, 
 if it be true that, as expressed by an eminent 
 scientist able to judge — Professor Sir W. Roscoe 
 — " It is, after all, by individual effort that all 
 true progress in science has been made," which 
 is an echo of the phrase that " Discoverers are 
 not manufactured, but born." Instead of 
 recognition of this feature, it would appear that 
 there is in prospect a system of discovery made 
 to order, a system connected with great outlay 
 and large reports, but one that will periodically 
 be dismayed and chagrined by the announcement 
 of overshadowing discoveries made in the natural 
 way, that, as Roscoe says, they ever have been 
 made. 
 
 The hope may be expressed that those in 
 power, who may discern that this tendency 
 would be disastrous, and who may appreciate 
 the search after truth for the regard for truth 
 alone, knowing that utility must follow, will 
 do their best to ensure that this national provision 
 intended to assist progress wiU be applied in 
 such a way as experience indicates is the true 
 method to secure the great advance and benefit — 
 individual and national — that is within reach. 
 
 If now we summarise what has been done in 
 Britain, limiting reference to the more im- 
 portant work, placing the foundational facts in 
 dark type, and the facts of much practical 
 utility in lighter type, it is found that the list 
 for Britain is lamentably small, but important 
 so far as it goes. 
 
 Discovery of Oxygen Priestley 
 
 'Priestley 
 Hales 
 Cavendish 
 Black 
 Bonnet 
 Ingenhousz 
 Percival 
 
 ^Senebler 
 
 Discovery of Carbonio Oxide 
 
 Its absorption and decamposltioii by 
 
 plants 
 
 ntlllsation by plants of Its Carbon . 
 Rajeotlon to air of its Oxygen . 
 
116 
 
 BetentlonbySollof Ammonia, Phosphate, \mr,„ 
 
 and Potash / ' 
 
 Formation of Soluble Phosphate, i.e. Super- Xrio^in- 
 
 phosphate . ; JL,\eDie 
 
 Elucidation of Nitrification in soils . . "V Warington 
 Determination of Nitrogen compounds In air V 
 and soils j Lawes 
 
 Availability of Insoluble Mineral Phosphates ■n 
 Cause and Bemedj; of Turnip Disease . . I 
 Self-cross fertilisation of Cereals and Grasses I t._,:_„„_ 
 Eeproductive method in Cereals and Grasses /■•'a™«son 
 Absorption and Utilisation of Nitrogen In I , 
 
 dir by pUnts ......'' 
 
X s^ M 
 
 
 I