732 



THE AHRTCULTURAL GAZETTE 



i , that such a power shoukl be attribute,! to 

 S?mS£i operations of vegetable life, until its 

 iSJZSShBd been either disproved by facts or at leas 

 £££* utterly at variance with the whole tenor of 

 «xperunental research. 



The same remark applies to the now .S^^ies^f 

 felled belief in the presence of nitrogen .« al JJ«« 

 p»in, and the consequent necessity for a supply of 

 Soma from one quarter or another to the growing plant. 



Th* first of these facts was ascertained by uay 

 Lu^ oTy wlhiTTfew years; the latter would even 

 recently be disputed by those who, like Mulder, and 

 Er lohJL, of Durham, contend for the possi- 

 biEyVf nitrogen being absorbed under certain c.rcurn- 

 S2m from the air, and being thus directly assimilated 

 by plan sTan opinion discountenanced as I conceive 

 Dy a reference to the general economy of nature, which 



appears 



ever 

 suggest* to os, 



rt to show, that the constituents of the atmosphere 

 maintain their relative proportions unaltered, and 

 __ that nitrogen must be conveyed to the 

 ffirthrongh'the medium of ammonia only, inasmuch 

 as there is every reason for supposing, that this element 

 cannot be made to abandon its elastic form through the 



influence of vegetative forces. . . 



Nothing indeed short of the powerful action of elec- 

 tricity will cause it to unite with oxygen, although the 

 strength of its affinity for this body is shown by the 

 stability of some of the compounds it forms with it ; nor 

 do we know of any other element capable of uniting 

 with it directly, except it be carbon, in an experiment 



not yet fully cleared up * 



It seems, therefore, a priori, improbable that the nitro- 

 gen of the atmosphere c an have any share in the 



nutrition of plants ; and so far as experiments have yet 

 .rone, the evidence is on the same side. 



I have recently grown Beans in an artificial soil, com- 

 posed of pounded brick, and enclosed a plant obtained 

 from them in an atmosphere, sufficiently supplied with 

 moisture, and renewed at regular intervals by the in- 

 troduction of fresh air taken from the outside of the 

 building in which the experiment went on, but from 

 which all the ammonia present had been carefully 

 removed, by passing it first through weak sulphuric or 

 muriatic acid. After a certain time the plant confined 

 in this atmosphere became feeble, mildewed, ana flabby ; 

 whilst another placed under precisely the same cir 

 stances, except that the air retained its ammonia, con- 

 tinued till the end of the experiment healthy, and 

 comparatively vigorous. (The two plants were shown 

 to correspond with the description above given, and the 

 apparatus in which the experiments had been carried on 

 was also exhibited.) 



vegetable exuviae 



'^■""^ cauvimj auu remains ou.'ht toT^" - ^^ 

 mountains of Africa, on heights extendinfw^ * 

 limits of perpetual snow, where no bird } d *• 

 finds food, from the absence of all v^^f. ?° *"»*. 



4. 

 ft, 



VI 



cum- 



in a 



popular lecture it did not teem desirable to dwell 

 upon the proof* of thU a»*ertion, but an it is opposed to the 

 opinion of certain »ble chemists, I subjoin the grounds upon 

 which I object to the arguments by which they maintain the 

 contrary. , , , „ 



AraulntnUfor and against the Theory of the Absorption of Gaseous 



Nitrogen by other Elements. 



1. When organic substances which contain no nitrogen are 

 on Used in the air, ammonia not un frequently is produced. 

 Answer.— This fact may be readily refen ed to the absorption 

 ©f ammonia by all spongy bodies, as has beeu shown by 

 Faraday, the ammonia being, of course, derived from the 



an sphere. . 



2. When moist iron-filings are eiposed to the air, and 



undergo oxidation, ammoni a U disengaged. Answer.— Berze- 

 Hus, Kapport,for 1844, admits that this experiment.* fallacious. 

 Will has also refuted it. 



3. When tin-tilings are rapidly oxidised by means of nitric 

 acid, ammonia is produced. Answer.— This experiment proves 

 nothing, as the Bitrogtfl and hydrogen, when they combine, 

 are both in a nascent state. 



4. It' a current of moist air be made to pass over re-l-hot 

 charcoal, carbonic acid and ammonia are simultaneously 

 formed. Answer.— This experiment I have mjself repeated, 

 but • ind that the ammonia did not continue to be evolved 

 after the experiment had been for some time prolonged. Hence 

 I conclude that it was derired from the charcoal, which had 

 absorbed it previoutly. 



5. If 40 parts of iron-filings be mixed with 1 part of hydrate 

 and I of nitrate o f po a*«, and then heated, ammonia becomes 

 perceptible. Answer — This experiment comes under the tame 

 cat- ry as experiment So. 3. 



6. Nitrate of potass is generated in hot climates where no 

 organic matters are present. Hence *e infer, that nitrogen arid 

 oxygen are made to combine directly through the agency of 

 porouh bodies, lime being present to unite with the nitric acid 

 formed, and the compound being afterwards decomposed by 

 pota«s. Answer.— It cannot be denied, that in most cases, and 

 in all those which have been fully examined, organic matters 

 were present where nitre was produced. If in any instance, 

 as in that of the caves of Ceylon, their presence cannot be 

 substantiated, may it not be, that the lime and potass attracted 



ammonia from the air, and that the nitric acid proceeded 

 from the oxidation of ammonia ? 



7. When a succession of electric sparks is passed through 

 common air, nitric acid is slowly but sensibly generated. 

 Answer.— I have repeated this experiment under circumstances 

 which exclude the objections which might be raised against 

 Cavendish's experiment, as originally performed, in which, 

 as potass was used, ammonia might probably have been 

 present in it. I am bound, however, to state, that even 

 when no potass was employed, and the air had beeu passed 

 through sulphuric acid, to deprive it cf ammonia, nitric acid 

 was produced by iheelcc"~ic spark, and therefore to admit that 

 tha direct union of nitrogen and oxygen may be accomplished 

 in this way. No ammonia could be generated, when hydrogen 

 and nitrogen were electrified together, by means of the 

 same powerful machine as that I ■ had uied successfully 

 for producing nitric acid. Yet the power of electricity to 

 cause the union of nitrogen and oxygen must be confined 

 to very narrow limits, or the quantity of nitric acid generated 

 on the whole body of the atmosphere would have been so much 

 greater than It is found to be, as to entail the destruction of 

 animal and vegetable life. 



8. Desfoasea showed, that when nitrogen was brought into 

 contact with carbon at a high temperature, an alkali being 

 present, a cyanide was produced, and Mr. Lewis Thomson i« 

 £iL£u m *^ a *• Ure PrU8 * ia » blue on a large scale on this 

 CLvJ Ln £ f ° WneS (Brit " Assoc - K *P' *«*• 10 >. appears to 



4 rlLr ThU ^ * ramonU ^ J * *» these caiei be present. 

 tZZLZC* w P enm * n ' "ems to establish the possibility of 



5? to com3 n Un,t1 ^ Whh Carbon ' ™ *• P"c«dini- one does 



charts a„S & "** °*l g *? 5* the P°™* ™"are of 

 cnarcoai, and us power of absorbing gasca, must be taken 



^/h^ a thT at 5 ** d '! ""*• therefore, still appear doubtfu^ 

 Z*£Z l^Z 5 W decided evidence, that nitrogen can be 

 made to abandon r S elastic iorm on the earth's surface, except 



So^H^^ 0f •»«**** «* ot the attraction 



ItVn t fwhE^ Ul ? ay bti Mk6d - ca » * mm °nia be produced 

 ™L£ n.rtT 8reat *Z" m would effect the ™&n of its 

 r^lrZ LI' tn iT C kn0W that their n,u£ « al affinity is 



father FIo*?hU n? Wp *?* Uaited * h ™ ™" bought 



tognher. How this pressure U brooirht .lmnt u «f „„„ * « 



The many bearings on practical husbandry which these 

 theoretical principles involve will not at the present day 

 be disputed— they lie indeed at the root of those questions 

 which have of late been so much agitated between Baron 

 Liebig on the one hand, and Mr. Lawes on the other, as 

 to the necessity of phosphates and of ammonia for the 

 success of certain crops, and are taken for granted by both 

 parties, notwithstanding the differences of opinion which 

 exist between them with regard to the utility of am- 

 moniacal and mineral manures under particular circum- 



StUl -CBS- 



It must be confessed, that this discrepancy of opinion 

 between the highest living authority on organic 

 chemistry, and an experimentalist who has undertaken 

 so elaborate and extended a series of researches with the 

 view of elucidating the theory of husbandry as Mr. 

 Lawes, is calculated to shake, the confidence of practical 

 men in the dicta of science. It may therefore be 

 not amiss to show, that this discrepancy is after 

 all confined within narrow limits, and by no means per- 

 vades the whole of their theoretical conclusions. 



Baron Liebig for instance, maintains, that provided 

 a plant be furnished with a sufficient quantity of 

 those mineral ingredients which are essential to its con- 

 stitution, in a form in which they can be readily taken up 

 and assimilated, it can dispense with any artificial 



supply of ammonia ; this being obtainable either from 

 the atmosphere, or from the rain-water with which its 



roots are moistened. 



He accordingly suggested to his friend, Mr. Muspratt, 

 of Liverpool, a set of manures compounded upon the 

 above principle, and calculated to meet the requirements 

 of the several descriptions of crops in use in husbandry. 

 These, although in fact patented by the above named 

 gentleman, became commonly known by the name of 

 the great chemist who devised them, a circumstance 

 which has given occasion to an anonymous writer in the 

 recent number of a periodical* to indulge in some 

 rather ungenerous and misplaced sneers against the 

 Giessen Professor; as if it had been beneath his dignity, 

 as a man of science, to seek pecuniary profit from his 

 own discoveries. 



I have already stated, that the patent was not taken 

 out by Liebig himself; but had the fact been otherwise, 

 it would have been strange to bring such a charge 

 against a Foreigner, in the country of the Arkwrights, 

 the Watts, and the Wedgwoods ; a country where a 

 Wollaston increased his wealth, without damaging his 

 reputation, by keeping to himself to the last hour of his 

 life a chemical secret ; and where at the present moment 

 the same Gentleman is engaged, without the slightest 

 impeachment on his respectability, partly in experi- 

 ments on agricultural chemistry, and partly in more 

 lucrative undertakings, as a vendor of manures. 



finds food, from the absence of all ve?e^;™ ?° 

 Why, indeed, should we be surprifed £ n 4 

 ivifying influence of the exuberant heat ^ and "^ 

 of the valley of the Nile, cereal crops should 1^2^ 

 effect that, which, according to Mr. LawJ? * k * 

 ments, it would appear that, even in our own W e * ! * rl 

 climate, plants, with a larger development of h^S** 1 

 capable of doing ; for how else are weto a econn/f' ? 

 fact, that Turnips, which contain more nitSS b * 

 portion than the Grasses, can dispense with amm ' **" 

 manures, provided only sufficient superphosphate*? 

 administered to them in an early stage of their a 

 On the other hand, the inutility of mineral inanlt! 

 can only be predicated with respect to land almfc 

 charged sufficiently with all the fixed in<n-eE£ 

 which the plants grown upon it contain, and that ttoT 

 not the case in all parts, even of our own countrv Jl 

 appear from the case already cited, in which the'nii! 

 tures of Cheshire were so strikingly improved b? 

 simple dressing of bones. ^ 



It cannot be contended, that what is true of som 

 species of Grasses does not hold good with respect to the 

 rest, and that it may not be possible hy injudicfcn 

 cropping to reduce other land, through the exhaustion 

 of its phosphates, to the same state of sterility as the 

 fields of Cheshire. 



The experiments which I have myself performed on a 

 small scale, and of which an account is given in the u Phi- 

 losophical Transactions," for 1 845,* tend to show that the 

 phosphates, as well as the alkaline salts present in the 

 soil, exist there in two different conditions, a part being 

 readily taken up by water containing carbonic acid 

 the remainder capable of being extracted at the time 

 only through the more energetic action of mineral acids. 

 It is reasonable to suppose, that the portion which 

 the former menstruum fails at once to dissolve, will 

 not be immediately available 

 the growing plant, but that 

 become so with greater or lesser 

 to the degree of energy with which the vegetable 

 processes are going on in the soil which contains it 



In the case of Mr. Lawes's land, which, at the rerr 

 time when it was considered by him as agriculturally 

 exhausted, produced 164 bushels of Wheat to the acre, 

 it cannot be supposed that the mineral phosphates were 

 actually deficient ; but it is very possible, that the 

 floating capital, as it may be termed, had been reduced 

 by previous cropping, so that it might require a certain 

 vigour in the plant to extract the requisite amount of 

 phosphate and alkali from the soil. By the application 

 of aramoniacal manures, this increased vigour may, as it 

 would appear, be imparted to the cereal crops, but not 

 to the Turnips, which latter would consequently oe 

 checked in their development, unless phosphate of lime 

 were added, in a more soluble, and more readily awiaoie 

 form, than that in which it existed in the soil. 



We should, however, have had more solid Pf*™" 

 proceed upon in this matter, had Mr. L^f^^ 

 an analysis of his soil, at the time when he m 

 sidered it to be in an exhausted condition, as w* 



the researches m ^ 



ight then have had 



for 

 it 



the 



purposes « 

 may nevertheless 

 rapidity, in proportion 



done by Mr. Way, B in 



ensrazed his able assistance 



which 1 



engaged his able assistance ; we mignu »-- > ^ 

 date for determining, how far the circumstances^ 

 farm corresponded with the average ones in otnerpu 



Whilst, then, Baron Liebig lays the greatest stress upon 

 mineral fertilisers; Mr. Lawes, on the other hand, infers* 

 from his experiments at Rothamstead, that cereal crops 



[arm corresponded auu *•«* «* — -©— i: mA remain- 



England, and what amount of phosphate oi ™ e ^ 

 ing in the land suffices for an abundant crop of cereajj 

 when other plants grown in it are benefited Dj 

 liberal supply of that mineral. tf t0 



Whilstf however, Mr. Lawes' experiment m 

 insufficient to overturn Baron Liebig s p^ 



me 

 to the 



of his 



rerturn w*i "" — ~ o * ^ g 



utility of mineral ^^J^^oca/ii 



general, I am by no means prepared to » . 



opinion which that great chemist in SOI ?^ he artificial 

 . works appears to countenance, namely, tna ^ 



are improved more by ammoniacal salts than by phos- application of ammoniacal salts is of no P™^^ by 

 phates, and that the latter are chiefly beneficial to "~ ' 



Turnips and other plants of a similar organisation. 

 Experiments of this description are doubtless valuable 

 as a guide to direct our practice, where the circum- 

 stances are similar to those under which they were 

 undertaken, and as an indication, that in the climates and 

 on the soils with which we have to deal, cereal crops are 

 unable to abstract from the atmosphere, or from the 

 soil, sufficient ammonia for an abundant crop, and, 

 therefore, require the adventitious aid of nitrogenised 

 materials. 



Before, however, we can admit their validity, as esta- 

 tTeTake^ ^ lishin S a general law applicable to all places and climates, 



it will be necessary, at least, to reconcile them with facts 

 well known to all the world, which point to an entirely 

 opposite conclusion. Thus, for instance, as Baron Liebig 

 observes, the fields in the Delta of the Nile are supplied 

 with no other animal manure than the ashes of the burnt 



I 



himself 

 this abnoi 



should rather avail myself of the •J^'J^tW 



in other passages which might w> 4 ^j 

 ormal supply of ammonia, a \ thou f f it . for if their 



,f plants, tends to accelerate ''' 'fro, 

 vithin a given time bej »J ^ fu r- 

 cceteris paribus, to the freedom with wmc* ^ , n - 

 nished with manures of this description. .,„„ in . 



development within a given 



„ iai in «. —.. ~ of "other JJJJSRI 

 fluences, the subsequent luxuriance ot » itspr eTioo» 



ferred, that in the absence 



some relation, at least, to the rapidity 



S 



owth. 





untenab 



excrements of animals, which form their principal fuel 

 brought about is of court* a in a countr y so denuded of wood ; yet they have been 



proverbially fertile from a period earlier than the first 

 dawn of history, and that fertility continues to the pre- 

 sent day as conspicuous as it was in the earliest times 

 These fields receive every year, from the inundation of 

 the Nile, a new soil, rich in those mineral elements, 

 which have been withdrawn by the crops of the previous 

 harvest. The mud of the Nile contains as little nitrogen 

 as the mud derived from the Alps of Switzerland, which 

 r „„„.„ „ . M fertilises the fields after the inundation of thp TihinA 



*^*£^^?tl^^^ this fertilising mud owed this ^Vrtfto nilro" 

 ab>. *r.r » ; ^ > S" e i s ~.* n .l e *J_L beaeTB . ^-ioued », | gentsed matters, what enormous beds of animal and 



matter of conjecture, but th. tWV -hinv, JZl "\Z 7 

 to take place ia the interior omSJLT^™ 8U PP oge * tbe un,on 

 for thU at well .1 for th. 1. , * h m<i * 8erTe to account 



eoc.no... TbUrboweVer, le no^ ^ he pi ace to ZTSLl 7"$ 

 •p«cul»-ion., which are oqIt alluded to in ^.Z^-T *t ch 

 U I. not nece,.ary to euppoie the aVmoni. '-Men i*i -7' ""I 

 aoi«ata requl^ h.ve'oeen " pent u'^SS?^ 

 it might be geoerated gradually by v.,lca„ J^ * „?*' J. ln 



In common, then, with the larger 

 men of science, as well as of P ract n X . c *\ "gaits, * "jT 

 I will take it for granted that ammon.aca ^^ 

 subordination to the earthy pho-P^** ^^ 

 in vegetation; and proceeding upon these P^^ove* 

 point out, as a real boon to mankind, a ytfkg hire, «J 

 of which Mr. Thomson, of Coot Hall, » *_ in Do * 



» 



the Rev. Mr. Huxtable, of Sutton ^^ ^ <£ 

 shire, seem to have had a glimpse » b ° ut wor ked <jJJ 

 but which has been since more iui ^ {h jwp 

 Professor Way, the consulting chen^t ffl# 



. , ■ nT • *... _..u«ozi name n&s " cc 



gradually by volcanic piocewe 



ce 

 which 



Lt «... -^-r.s 5S5 



i, erer isnee Uj. time of Werner. 



• « 



Edinburgh Review " for July, article •• Chemistry .» 



Agricultural Society, whose name 

 than once referred to. 



I allude to the 

 property, not merely of detaining, ' °> p erc ol»te 

 affinity, saline matters when maoe r e 

 them in solution in water but jtao^ ^ ^ 

 effecting decompositions m those pre* ^ .^^ 

 kind which would^noUak^p^^j— ^CrtP»- 



VBakeri^UcTu^O** 6 Bot * 



