AGRICULTURAL CHEMISTRY AND VEGETABLEPHYSIOLOGY.DURING the past year the activity of the many workers in thisvery varied field, which includes the chemistry of the soil and ofthe nutrition of both plants and animals, has been well maintained,although nothing very novel has come to light either in the wayof a discovery or a new point of view. We are advancing towardsan analysis and a reconstruction of all the varying play of forcesinvolved in the growth of a plant from seed round to seed again,but in reviewing the progress effected during a year one is moreconscious of the flight of time than of the lessened distance to thegoal. Very often, indeed, a large proportion of the work seemsto be devoted to the undoing of previous investigations, but theconditions under which a plant grows are so complex, and itsdevelopment represents the resultant of so many different actions,that investigations which seem t o lead to definite conclusions inthe laboratory are apt to be true only for that particular set ofcircumstances, and to have only a limited application to the openfield, where the results may be determined by some other factor nottaken into account in the experimental work.Soil Bacteriology.I n connexion with the bacteriology of the soil, attention is stillmainly directed to the question of nitrogen-fixation, for althoughthe main facts are not in doubt, there are considerable differencesof opinion as to the magnitude of the part played by the differentraces of nitrogen-fixing bacteria in Nature.As regards Azotobacter C ~ ~ O O C O C C Z L ~ , the most active of thebacteria which fix nitrogen when free in the soil, its originaldiscoverer, M.W. Beyerinck,l has abandoned the idea, which heonce put forward, that the actual fixation is effected by anotherorganism, Radiobacter, living in symbiosis with Azotobacter ; henow agrees with the many other observers, who kept to his originalopinion, that Azotobacter is the effective agent. Beyerinck suggests,1 Proc. K. Akad. Wetensch. Amsterdam, 1908, 11, 6’1 ; A . , ii, 9’15AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 243the use of calcium malate, instead of mannitol or glucose, in theculture media used for identifying the presence of Azotobacter insamples of soil, because a larger number of organisms develop intocolonies on this medium tha,n on the more usual ones containingsugar.He also makes the interesting statement that colonies ofAzotobacter seem to be associated with the roots of leguminousplants even when they are not abundant in the rest of the soil,an observation which requires careful examination to see if thisassociation is confined to leguminous plants. Krzemieniewski 2explains the superior nitrogen-fixation per gram of sugar oxidisedwhich is found when the inoculation is made with a raw soil extractinstead of a pure culture of Azotobacter, as due to the smallquantity of soluble humate that is added with the soil extract.It was found that pure cultures of Axofobacter could be stimulatedto a much greater fixation by the addition of a little sodium orpotassium humate.On the other hand, Lohnis and Pillai 3 concludethat humus alone is about the least effective source of carbon forthe Azotobacter organism, mannitol and xylose being most effective ;dextrose, starch, sodium tartrate, calcium lactate, sodium propionateare successively lower down in the scale. These authors also give aseries of measurements of the activity of the organism in soils thathave received different manurial treatment, and in the same soila t different times of the year; but their results are not veryconvincing, probably because their method of determining theactivity of the soil was not satisfactory. Among the chief desideratain connexion with soil bacteriology are satisfactory methods formeasuring the power of a given sample of soil to bring about certainkinds of bacterial action, for example, nitrogen-fixation, nitrifica-tion, production of ammonia, protein fission, etc.; for none of thosewhich have been hitherto proposed seem to give results in accordwith the field experience. Stoklasa and his co-workers4 have alsodiscussed the relationship of Radiobacter to Azotobacter, and findthe former of little value as a nitrogen fixer; they, too, havecompared the various sugars as sources of carbon for A zotobacter,and state that I-arabinose is the most effective, and that all theother monosaccharides possess much the same value, considerablyabove that of the disaccharides. The same workers have beenstudying the chemical reactions involved in the fixation of nitrogen ;they found that from dextrose the chief product was carbondioxide, but ethyl alcohol, formic, lactic, and acetic acids were alsoproduced, * and some hydrogen was always liberated.Stoklasa isBUZZ. Bcacl. Sci. Crncow, 1907, $46.Centr. Bakt. Par., 1908, ii, 20, 781 ; A , , ii, 522.Ibid., 21, 484, 620 J A . , ii, 880, 975.R 244 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.very positive above the hydrogen and the ethyl alcohol, the forma-tion of which other observers have denied; but in all probabilitythe reaction varies with the source and the activity of the particularculture of ,4 zotobacter employed.The magnitude of the part played by Azotobucter in Nature isstill a matter of uncertainty.J. G. Lipman 5 has made a numberof inoculation experiments with soil treated in various ways, butwithout any very positive results to show that the Azotobucter hadsucceeded in fixing enough nitrogen to affect the yield of the cropafterwards grown in the soil. As this author, however, verysoundly points out, the mere inoculation of a given organism intoa soil in which it was previously lacking, is never likely to resultin its establishment therein, unless a t the same time the generalsoil conditions are made suitable for it. The absence of theorganism is in itself most probably an indication that the soil isnot a fit medium for its growth, nor can it be established untilthe inhibiting factors have been removed.Since the discovery of Clostridium, Aeotohacter, and their relatedorganisms which will fix nitrogen when grown on suitable nitrogen-free media, the power of fixing a little nitrogen has been attributedto a large number of other organisms; indeed, it has been supposedto be a property common to all oxidising bacteria under fittingconditions ; Bredemann reports studies on a bacterium onlyabout one-fourth as effective as Azotobacter.Frohlich 7 makes outthat certain fungi associated with dead leaves, etc., possess thepower, whilst Hannig8 maintains that a certain grass, whenassociated with a parasitic fungus on the root, will bring some freenitrogen into combination.As regards the nitrogen-fixing bacteria associated with leguminousplants, there is nothing new to record; cases continue to be reportedwhere inoculation of the ground with the nodule organism hascaused a marked increase in the yield of the crop, but they referto relatively exceptional soils or crops ; under ordinary farmingconditions nothing appears to be gained by inoculating the seedsof such staple crops as clwer or beans.Reports appear from timeto time that the nodule organisms have been made to associatewith non-leguminous plants, but no evidence is yet forthcoming.Nitrification continues to receive some attention; L. C. Coleman 9has been studying the effect of organic matter, which the earlyinvestigators of nitrification had regarded as inhibitory of nitrifica-28th Ann. Rep. New Jersey State Agric. Exper. Stat., 1906-1907, 141 ; A ., ii,Centr. Bakt. Par., 1908, ii, 22, 44.Centr. Bakt. Par., 1908, ii, 20, 401, 484 ; A , , ii, 315.615.Ibid., 21, 162.8 Bey. Do&. bot. Ges., 1908, ii, 26a, 238 ; A . , ii, 523AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 245tion. He found, however, that small quantities of dextrose, upto 0.5 per cent., increased the rate of nitrification in non-sterilisedsoils, and a similar effect was seen when 0.02 to 0.05 per cent. ofdextrose was added to pure cultures. Karpiliski and Niklewski 10obtained similar results with humates and soil extracts, also withsugar and acetates, which latter salt Coleman found injurious tothe process. These contradictions, which are always turning upwhen the nutrition of bacteria is being examined, only emphasisethe need for caution in drawing conclusions from laboratoryexperiments as to the behaviour of soils in the field.Hall, Miller, and Gimingham 11 have examined the biologicalcondition of some of the Rothamsted soils which have become acidthrough the repeated application of ammonium sulphate andchloride.I n these soils, nitrification is practically a t a standstill,and the nitrification organisms are only to be found sparsely, ifa t all. The authors show that the acidity is mainly due to freehumic acid, although a little hydrochloric and sulphuric acids mustalso be present to a greater extent after the application of themanures than later in the year. The acid arises from the ammoniumsalts, which are split up by certain micro-fungi and moulds abun-dant in the soil of these plots, the ammonia being utilised bythe fungus and the acid set free.These acids have year by yearattacked the calcium humate in the soil and set free humic acid,which, being sparingly soluble, has accumulated. The poor growthto be seen on these acid plots may be put down to the fact thatthe grasses are driven to draw their nitrogen directly from theammonium salts without previous nitrification, and generally to themanner in which the acidity of the medium causes the replacementof the normal bacteria in the soil by a fungus flora, which competeswith the crop for manure and plant food in the soil.Hall and Miller l2 have attempted to oxidise by soil bacteria thenitrogen compounds contained in powdered rocks taken from greatdepths beyond the reach of any weathering processes, chiefly clayswhich show a considerable proportion of nitrogen.They foundthat some of this maherial was convertible by bacteria intonitrates-more than could be accounted for by the ammonia whichthey also found to be always present in these rocks. The processof nitrification is, however, very slow, and the authors considerthat some of the nitrogen compoiinds in soils may originally havebeen present in the rock out of which the soil was formed byweathering, being, as it were, in a mineralised condition unavail-able for the plant.lo Bull. Acad. Sci. Cracow, 1907, 596 ; A . , ii, 123.11 Proc. Roy. Xoc., 1908, 80, B, 196 ; A . , ii, 624. l2 J. Agric. Ski, 1908, 2, 343246 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.M.C. Potter 13 has isolated an organism from garden soil capableof oxidising amorphous carbon in the form of coal, peat, charcoal,etc., which would seem to indicate that such fossilised organicmatter is even more attackable by bacteria than previous observershad supposed.The question of whether the soil bacteria aid in the solution ofsuch nutrients as tricalcium phosphate has received further atten-tion. Perotti14 considers that the attack only takes place whenthe nitrogen compound present in the culture medium is aphysiologically acid one, for example, ammonium sulphate, andthis would agree with Soderbaum’s experiments.15 Sackett, Patten,and C. W. Brown,l6 however, think that other factors come into play,such as the carbon dioxide excreted by the organism, or the specificacid it will form when supplied with an appropriate source ofcarbon.Even the potash of leucite is attacked when it is intro-duced into cultures of acid-producing moulds.17Voorhees, Lipman, and 9. E. Brown 18 have examined some of thechemical and bacteriological results of liming the soil, and findthat after an application of lime the bacterial activity of the soil,as measured by its power of making ammonia from gelatin or itsnitrate content, is considerably increased. I n their trials, purelime was more effective than a magnesian lime made from dolomite,and calcium carbonate was often more effective than either.Soil C l ~ e n ~ i s t ry .The theory of the action of fertilisers, which we owe to Whitneyand his colleagues in the Bureau of Soils of the U.S.Departmentof Agriculture, has received considerable developments during theyear. Briefly, the theory is that each plant excretes duringgrowth certain substances toxic to itself but not to other plants;infertile soils are those in which such substances have accumulated;fertilisers act, not by directly feeding the plant, but by neutralisingor otherwise putting out of action the toxic bodies excreted byprevious crops. Since last year’s Report the point of view seemsto have changed somewhat; no further work is reported on whatwas the prime hypothesis (that the soil water possesses a constantcomposition which is unaffected by the addition of fertilisers) andinstead of excretion from the plant itself, the toxic substances are‘l3 P~oc.Roy. SOC., 1908, B, 80, 236 ; A , ii, 524.l4 Atti R. Accad. Lincei, 1908, [v], 17, i, 448; A . , ii, 527.l5 Landw. Versttchs.-Slnt., 1908, 68, 433 ; A . , ii, 728.l6 Ccntr. Bakt. Par., 1908, ii, 20, 688 ; A . , ii, 415.l8 New Jersey State Aqric. Exper. Stat. Bttll., 1907, 210 ; A , ii, 317.Grazia and Camiola, Bied. Zen.fr., 1908, 37, 207 ; A . , ii, 415AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 247now supposed to arise from the action of bacteria, etc., on theresidues left by the crop in the soil. This is a different hypothesis,which, with a little extension to include the action of the bacteriathemselves, and the abandonment of the quite unnecessary sup-position that fertilisers precipitate or destroy the toxins, it is onewhich merits very careful attention, as affording an explanation ofvarious difficulties met with in the field.The most noteworthyfacts in this connexion are the isolation from certain infertile soilsby Schreiner and Shorey l9 of small quantities of two substances,picolinecarboxylic acid and dihydroxystearic acid, which the authorsregard as toxic. Both these substances were obtained from thecoloured extract which remains after an alkaline extract of theorganic matter of the soil has been precipitated by an acid; theywere prepared in crystalline form, and have been duly identified;the picolinecarboxylic acid may be regarded as a product of thedecay of protein in the soil, just as dihydroxystearic acid maywell be a derived product from some plant fat containing oleic acid,or possibly of a protein also.Evidence is brought to show thatboth these substances, and especially the ,latter, are toxic tovegetation, and the conclusion is further drawn that they con-stitute the source of the infertility of the soils from which theyare derived. From 1 kilo. of an infertile cotton soil, 0.05 gramof dihydroxystearic acid was obtained, although more was presentin the soil. It is just the evidence f6r the toxicity of these com-pounds which seems open to criticism; the method employed wasto place series of ten young wheat seedlings in bottles containingdistilled water, to which varying amounts of the substance underinvestigation have been added.The growth of the wheat seedling(which was still deriving its nutriment from the endosperm) wascontinued for about ten to twelve days, and was measured both bythe amount of water transpired and by the increase in weigh1 ofthe seedling. The following table shows the sort of numbersobtained :Transpiration. Green weight.Control-distilled water only . . . . . . . . . . . , . . . . . . . . .1 per million of picolinecarboxylic acid ... ... 140 9510 7, 9 J ,, ...... 105 10150 2, 9 , , , . . . . . . 107 98100 , 7 $ 9 , , . . . . . . 85 892oo 1 1 Y Y ,, ...... 55 70100 100To anyone acquainted with the great individuality exhibited bywater cultures, and the many ways in which such experimentswill fail even when growth is going on in nutrient solutionsand not in water alone, these figures will not appear very con-l9 J .Amer. Chem. Soc., 1908, 30, 1295, 1599; A . , ii, 889, 1067248 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.vincing. No actual weights are given, and although we gatherthat the trials were made in duplicate, the two sets are not givenseparately; thus we have no means of estimating the experimentalerror, which we know must be large. Furthermore, a substancemay be very toxic in a water culture, where the plant is set togrow in distilled water and nothing else, but there is no guaranteewhatever that it will behave in the same way in the soil, whichpossesses an enormous power of withdrawing organic substancesfrom solution. The substances which Schreiner and Shorey haveisolated are of great interest, and open up a new field in the studyof the organic matter of the soil, but they demand a good dealmore investigation before they can be accepted as the causes ofthe infertility of the soil.For example, a soil rich in organicmatter-the accumulation of previous vegetation-is in most casesextremely fertile; are such soils richer or poorer than the averagein these so-called toxins?In another paper, Schreiner and Reed20 attempt to show thatvarious bodies used as fertilisers destroy or otherwise mask thetoxic action of organic plant poisons on wheat seedlings. Thefertilisers employed were sodium nitrate and calcium carbonate,the toxins, coumarin, arbutin, and cinnamic acid, and the methodof experiment has already been described.The authors give thefollowing table to show the beneficial action of calcium carbonate.rNoaddition.100133,, 25 ,, ..................... 80Control : distilled water oiily.,. .........Vanillin 1 per million .....................,, 10 ,y ..................... 126,, 100 ,, ..................... 53,) 500 ,) ..................... 25CaCO, arldcd2000 per million.2092011841831271 O iAgain no actual results are given by which the experimentalerror may be checked; the increases seen with 1 and 10 per millionof vanillin are set down to the stimulus brought about by smalldoses of poisons (no case has yet been made out for the generaltruth of this theory of stimulus), but no explanation is attemptedof the fact that calcium carbonate added to the pure distilledwater in the control experiment increased the growth from 100 to209.By parity of reasoning, the distilled water must have beenthe toxin in this case.Schreiner and Sullivan 21 claim to have extracted from (( wheat,-sick ” soil a substance toxic to wheat, and from ‘( cow pea-sick ”soil a substance toxic to cow peas, although not to wheat, but nodetails are yet given.J. Amer- C7~m. Soc., 1908, 30, 8 5 ; A . , ii, 420.a1 J. Bid. Chem, 1907, 4, sxvi ; A , , ii, 422AGRICU1,TURAL CHEMISTRY AND -VEGETABLE PHYSIOLOGY. 249We have dealt with these papers a t some length because it isonly by close attention to the details that they can be judged;each of the papers which emanates from the Washington Divisionof Soils begins with a convinced exposition of the theory to beproved, and the reader does not always see that the experimentswhich follow, although they will agree with the theory, are veryfar from a demonstration -of its truth.If the American authors of the theory seem to be weakening ontheir original hypothesis that the plants excrete the toxins, theirold view has found an independent supporter in India. F.Fletcher22was led by certain considerations as to the vigour of the plants inthe outside rows of experimental plots, the well-known “ falloweffect,” to regard this increased growth as due to the comparativefreedom of their roots from toxins excreted by neighbouring plants.He then proceeded to make water cultures with certain plants,cotton, sorghum, etc.; he grew young seedlings in well-water fortwenty-one days, three times in succession in the same liquid,the volume being kept constant by fresh additions of water.Finally, the solutions thus obtained were allowed to evaporatein a room until in each case about 20 litres of original well-water were reduced to something between 1 and 2 litres.Intothese liquids fresh seedling plants were put to grow, but werefound to wither and die very quickly, a result the author setsdown to the concentrated toxic excretion. On this part of thework certain criticisms suggest themselves-the plants grown inthe solutions were really large germinating seeds, in the stage,therefore, of breaking down the protein and other reserve materialscontained in the seed.It is well known that the roots of suchyoung seedlings will part with soluble nitrogenous and othercompounds to any solution in which they are growing, but onemust not argue from the germinating seedling to the normalgrowing plant, which, as a rule, has not such an excess of nitrogenas to be able to waste any in excretions. Moreover, these watercullares were made in broad, flat vessels, and were allowed toconcentrate by standing in a room a t an Indian temperature; inwhat sort of a bacterial condition were they likely to be a t the end,and what products may not have been formed! There is someindication that the toxicity of the solutions followed the size of thegerminating seeds utilised in each case, but data are lacking.Again, well-water, concentrated to one-tenth of its volume withoutany check against bacteria, may itself provide something toxic,and it is significant that the worst results were obtained in thecase where 23 volumes of well-water were concentrated into one foraz Mem.Dept. Agric. Zndicc, Bot. Xer., 1908, 2, No. 3 ; A., ii, 617250 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the final test. Other difficulties could be raised, but these willbe enough to show that the author subjected his results to nocritical examination; it seems a property of this toxin hypothesisthat its holders set out with the theory and are content if theirexperiments will fit, without risking any crucial experiments totry whether they will fit that theory only and no other.Fletcher considers that his results show all crops to yield thesame toxin; he gives a number of reactions which the substanceshows, for example, it is precipitated by potassium hydroxide,sodium chloride, dilute sulphuric acid, among other reagents, butin view of the very doubtful origin of the material it is perhapshardly worth while considering what these reactions indicate.S.U. Piekering23 has also entered the “soil toxins” field ofdiscussion with a series of experiments showing that many seedsgerminate more slowly in soil that has been heated, the “incuba-tion” period increasing with the temperature from 60° to 1 5 0 O .I n general, the percentage germination also diminishes with thetemperature.The soils are shown to contain more soluble matter,both organic and inorganic, after heating, and it is to this increasein the soluble nitrogenous matter by heating that Pickering attrj-butes his results. He concludes that most soils contain substancesfavourable to germination which are converted into inhibitorysubstances on heating, although some soils probably containinhibitory substances at starting. Pickering also considers thatthis increase of soluble nitrogenous bodies accounts for the resultsobtained by Darbishire and Russe11,24 who found that the growthof plants is much increased by a preliminary heating of the soil,in which case the substances which retard germination eitherbecome destroyed before plant growth begins or have no necessaryconnexion with it.Pickcring dismisses soil bacteria as an effectiveagency either in his own or in Darbishire and Russell’s results, buthis original experimental figures seem to form too slender a founda-tion for the wide conclusions he draws from them.Soil Physics.This branch of the subject is still sadly neglected, although it isrecog-nised that both the soil flora and the nutrition of the plantare determined more by the movements of water and air in thesoil than by any other single factor; during the year, however, oneor two interesting papers have appeared. F. J. Alway25 has mademeasurements of the soil moisture in the semi-arid i‘ great plains ”regions of Saskatchewan and the North-West. He obtained28 J. Agric.Xci., 1908, 2, 411.25 J. Agrie. Sci., 1908, 2, 333.24 Ann. Report, 1907, 265AGRICULTURAL CHEMISTRY AXD VEGETABLE PHYSIOLOGY. 251samples, by means of an auger, down to the depth of six feet fromland which had been cropped and from adjacent land which hadbeen fallowed in order to accumulate the rainfall for a crop in thesucceeding season. By determining the hygroscopic moisture ofeach sample, that is, the amount absorbed by the dry soil from asaturated atmosphere, and regarding the difference between thisand the actual water in the soil when sampled as the ‘( free ” waterwhich would be available for a crop, the author claims to be able todecide, a t the commencement of a season, whether the land containssufficient water for the needs of a crop.The author incidentallydenies that the soil in this region is frozen permanently, or that itsgradual thawing throughout the growing season keeps the cropsupplied with moisture. Alway’s figures would seem to indicatethat the crop chiefly depends for its water upon the store in thetop six feet-or so of soil, and that the moist soil below this yieldsup very little water by capillarity to the layers above. This isthe contention of J. W. Leather,26 who made a series of determina-tions of the amount of water a t various times during the year inthe uniform fine silt which constitutes the Indo-Gangetic alluviuma t Pusa. From the fact that a t about seven feet below the surfacea layer occurred which contained the same proportion of watera t the beginning and end of the dry period, Leather concludes thatthe loss of water by evaporation is confined to the higher levels,and that movements of water by surface tension from greaterdepths up to or near the surface do not take place.Leather’sresults, however, would be equally consistent with the view thatthe layer in question is in a condition not of static, but of dynamic,equilibrium it5 regards its water content, and that instead of losingno water to the layer above during the dry period, it has beenbalancing its losses by gains from below. The point can only besettled by determinations of the actual quantity of water lostby evaporation ; considering the importance of this question of therise of the subsoil water by surface tension or capillarity, it isvery desirable that further experiments should be set on foot.Souniversally is the capillary uplift of water from the subsoil regardedas the source of the resistance of certain soils to drought, that itis surprising to find how few and untrustworthy are the databearing on the subject.The question of the flocculation of the finest soil particles bysalts2’ has again been discussed by Rohland,28 who connects itwith the plasticity of the clay, the permeability of the soil to26 Mem. Dept. Agric. India, Chenz. Series, 1908, 1, 79.27 Ann. Report, 1907, 269.28 Lnndw. Jahrb., 1907, 36, 4i3; A., ii, 59252 ANNUAL REPORTS OX THE PROGRESS OF CHEMISTRY.water, and its surface tension and absorptive power, all of whichproperties depend on the colloidal substances in the soil formedby the weathering of the felspars.Chemist? of the Growing Plant.The supposed photosynthesis, outside the plant, of formaldehydeand then of starch, by Priestley and Usher 29 has been subjectedto severe criticism,3O and their work is generally only regarded asaffording support to the hypothesis that formaldehyde is the inter-mediate step between carbon dioxide and a sugar, although E.Baur31 discusses the possibility of oxalic acid being the first stagein the synthesis.The formaldehyde theory is supported by B.J. Harvey Gibson,32who has published a short note outlining a theory of photosynthesis,according to which the passage from carbop dioxide and water toformaldehyde is brought about by electric currents in the leaftissue, generated by the incidence of the light rays. He is ablet o show by a new test that formaldehyde is present in all greenleaves, the amount present bearing a definite relation to theillumination, and he also shows that a silent electrical dischargewill generate formaldehyde in a solution of carbon dioxide.Theelectric currents in the leaf tissues and their variation with theillumination have been demonstrated by other investigators.S. Strakosch 33 has been studying the other end of the assimilationprocess as it goes on in the leaf of the beet; he finds only dextrosein the mesophyll; sucrose appears later in the leaf veins aftermigration of dextrose has begun. Starch is not found until laterstill, after there has been some accumulation of sugars in the leaf.The formation of sucrose is dependent on light, but the amountof monosaccharides in the leaf remains almost constant whetherthe leaves are exposed to light or kept for some time in the dark.The sucrose migrates from the leaf to the root without undergoingany change, whereas, according to F.S t r ~ h m e r , ~ ~ when the reversenigration takes place in the second year of the plant’s growth, thestored sucrose in the root is converted into invert sugar before itcan be moved back to the leaf, where it is re-synthesised.The old question of whether t-he endosperm of barley and similar* Proc. Boy. Soc., 1906, B, 77, 369; A . , 1906, ii, 299.90 Ewart, ibid., 1908, B, 80, 30; A., ii, 217 ; Mameli and Pollacci, Alti 3.31 Zeitsch.physikal. Cham., 1908, 63, 683 ; A., ii, 790.32 Ann. of Botany, 1908, 22, 117.33 Zeitsch. Vcr. deist. Zuekcriizd., 1907, 1057 ; A . , ii, 125.34 Oesterr.-umg. Zeitsch. Zuckerind. Anndw., 37, 18 ; A , , ii, ’126.Accnd. Lincci, 1908, [v], 17, 1, 739; A., ii, 881BGIiICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 253seeds possesses any vitality, or is to be regarded as a dead magazineof reserve food, has continued to attract attention. D. Bruschi35brings evidence to show that the vitality varies with the natureof the seed; all gradations may be observed between maize, in whichthe glutinous part of the grain is alive, and rye, in which theendosperm is wholly dead ; wheat and barley being intermediate,in that a few layers of cells below the aleurone layer retain somevitality.F. Stoward 36 shows that the purely endospermic tissueof both barley and maize will respire and exchange carbon dioxidefor oxygen, thus bringing evidence of another character in favourof the continued vitality of these cells.The changes taking place in the nitrogenous compounds ofplants when the proteins are hydrolysed during the germinationof seeds and subsequently reformed in the growing shoot, continueto attract much attention, since on these very complex actionsdepend a good many technical differences of importance which thepractical man sums up under the name of quality ” in the seedsor their products. H. T. Brown has published two importantpapers37 on the soluble nitrogen compounds in malt and on themovements of such bodies from the endosperm into the embryo,as studied by presenting them to the detached embryo in watercultures.Asparagine was found to be the best nutrient, and wasproved to exist in malt, but it was not settled whether it was to beregarded as a down- or an up-grade product. N. Wassilieff,38 instudying the formation and migration of proteins during theripening of seeds of lupins, finds asparagine in the unripe fruits,but regards it as a,n intermediate stage in the upbuilding ofproteins from amino-acids, previously formed by the hydrolysis ofproteins in the husks, etc. Scurti and Parrozzani39 came to theconclusion that in the germination of sunflower seeds asparagine isnot a down-grade product formed directly from the proteins, sinceit only is found during the more advanced stages of the germinationprocess when the up-grade actions have begun.The organic phosphorus compounds of seeds and plants areattracting increasing attention, and a number of papers 40 have35 Ann.of Botany, 1908, 22, 449.57 Trans. Gainness Lab., 1, ii, 288; A., ii, 882 ; J. Inst. Brewing, 1907, 13,38 Ber. Ueut. bot. Qes., 1908, 26a, 454 ; A . , ii, 976.40 Stutzer, Biochem. Zeitsch., 1907, 7, 471 ; A., ii, 124 ; Suzulri and Yoshimura,Bull. COX Agric. T6ky6, 1907, 7, 495 ; A . , ii, 124 ; Winterstein and HiesstandZeitsch. physiol. Chin., 1908, 54, 288 ; A., ii, 218 ; W. Windisch, Jahrb. Yers.Lehr. Braucri, 1907, 10, 56 ; A., ii, 528 ; E. Schulze, Chent.Zeit., 1908, 32, 981 ;A . , ii, 977.36 Ibid., 415.394 ; A., ii, 883.Gazzetta, 1908, 38, i, 216 ; A., ii, 417254 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.appeared on the determination of lecithin, phosphatides, phytin,etc., in plants. No general conclusions can yet be drawn, but thesesubstances will have to be kept in mind in connexion with problemsof ripening and quality.I n opposition to Willstatter,41 Stoklasa, Brdlik, and Just 42maintain that chlorophyll contains phosphorus, and is a lecithin-like substance which yields choline and glycerophosphoric acidamong its decomposition products.M. Wagner43 describes a series of experiments to ascertain howvariations in the nutrition, such as a deficiency or an excess ofnitrogen, will affect the development of the plant in such charactersas the relation of straw to corn, the time of ripening, etc.Theexperiments were made in pots with barley, oats, buckwheat, andmustard. It is not possible to draw any very general conclusionsfrom the results, although the paper should not be neglected byanyone interested in the specific functions of the elements ofnutrition; amongst other things, it is noticeable that the author’sopinion is against the view that phosphoric acid gives a specialstimulus to root development.E. Molz 44 has published a long study of the well-knownphenomena of chlorosis which occurs in the leaves of the vine andother plants, generally when growing on heavy calcareous soils. Heassociates its appearance with the formation of a putrefactive layeron the surface of the root, followed by the entry of calcium car-bonate and the consequent neutralisation of the sap, and bringsevidence to show that such conditions as would further any ofthese actions are recognised in practice as favourable to chlorosis.I n one or two districts in England, fruit trees and allied plants aregrown with difficulty because of their tendency to assume thischlorotic condition; the causes of the disease have never beencleared up, and it would be well if the cases were re-examined inthe light of Molds conclusions.The stimulus to the growth of plants which has been ascribed tothe salts of manganese forms the subject of several papers45 publishedduring the year, but the subject has received no real advancement,because it has not been settled if the supposed stimulus is due todirect action of the manganese on the plant or to some secondarydl A m a l w , 1908, 358, 267 ; A ., i, 199.42 Her. Deut. bot. Ges., 1908, 260, 69 ; A . , i, 279.43 Landin. Versorchs.-S’tnt., 1908, 69, 161 ; A . , ii, 1066.44 Centr. Bakt. Par., 1907, ii, 20, 71.H. vori Feilitzen, J. Lnmiw, 1907, 55, 289 ; -4., ii, 61 ; Uchiyama, Bdl. Imp.Centr. Agric. ExpeT. Stat. Japan, 1907, 1, 37 ; A . , ii, 126; W. F. Sutherut,.Transcaal Agric. J., 1908, 6, 437 ; A., ii, 628 ; Gre‘goire, Hendrick, and Carpiaux,BuEL Inst. Chim. Baet. Gembloux, 1908, No. 75, 66 ; A . , ii, 529AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 255action on the soil. In all these stimulus effects the prime fact of theexistence of increased growth also requires to be put beyond thereach of doubt, just as in the kindred case of the action of high.tension electrical discharges on plants, an old question which hasarisen again this year as the outcome of a large scale experimentnear Worcester.46Manures und Manuring.As regards fertilisers and manures, the record of the year issingularly blank.The new nitrogenous fertilisers, calcium cyan-amide (either “ kalk-stickstoff ” containing free lime or ‘( stickstoff-kalk ” containing calcium chloride) and nitrate of lime, continueto be the subject of a number of field trials, because they arebeginning to be put on the market in considerable quantities, buttheir behaviour is pretty much what was indicated in the earliesttrials.Considerable dispute still rages as to the exact nature ofthe decomposition calcium Cyanamide undergoes in the soil, andwhether bacteria are essential in bringing about the change, aswas originally maintained by Lohnis. A. D. Hall47 has alsopublished some experiments on the losses of ammonia experiencedby cyanamide on storage under moist conditions, and on the prac-ticability of mixing the f ertiliser with superphosphate before sowing.The heat developed is not unmanageable, there are no losses ofnitrogen, but the soluble phosphoric acid of the superphosphatebecomes precipitated ; the mixed fertiliser is, however, much moreconvenient for sowing than the original cyanamide.M. Popp 48 has continued the well-known experiments of Wagneron the f ertilising value of different compounds containing nitrogen,the experiments being made in pots, in some cases continued forthree or four years.From the final summary, giving the mean ofall the experiments, numbers like the following were obtained :I f the returns from nitrogen in sodium nitrate be taken as 100,then an equivalent amount of nitrogen in dried blood will return72, in horn meal 71, in castor cake 65, in bone meal 52. It hasnever been found possible to confirm these ratios in field work,where other factors come into play, particularly the influence ofthe fertiliser on the texture of the soil.Chemistry of Animal Nutrition.Since i t is generally accepted that during digestion the proteinsof the food are very completely broken down to amino-acids, etc.,before they are reconstructed in the intestinal wall, among the dataNature, 1908, 78, 331.Landw. Verszcchs.-Xtat., 1908, 68, 253 ; A , , ii, 727.J.Board Agric., 1908, 14, 654256 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.required for an adequate theory of animal nutrition is a knowledgeof the products of hydrolysis of all the proteins commonly occurringin feeding stuffs. Practical graziers know by experience that theproteins of all foods are not of equal value, nor is the same proteinequally suited to all animals, but it is only recently that we seeany means of placing these empirical results upon a, scientificbasis. Osborne and his co-workers have taken up this problem ofthe resolution of the vegetable proteins into their constituent amino-acids with great vigour, and during the year report49 the resultsof the hydrolysis of amandin, gliadin, hordein, zein, vignin,legumin, legumelin, leucosin, and vicilin. A.Kleinschmitt 50 hasalso reported a hydrolysis of hordein. The imperfection of maizeas a food is attributed by S. Baglioni51 to the imperfect digestionof the zein, which yields on partial hydrolysis large quantities ofphenylalanine in addition to phenolic compounds. The author seessome similarity between the symptoms of phenolic poisoning andtiJose exhibited by animals dying through exclusive feeding onrmize flour, but he does not seem to have taken into account theexperiments of Miss Willcock and Hopkins,52 who associate thenitrogen starvation which sets in when zein is the only nitrogenousfood with the absence of tryptophan (and also lysin) from the zeinmolecule.0. Kellner 53 discusses the lack of agreement between the amountof digestible protein in a feeding stuff as determined by pepsin,etc., and the figures, varying in themselves, obtained from estima-tions of the nitrogen in the fzces of different animals. Forexample, the digestion coefficient of the crude protein of potatoes,as determined by feeding experiments, was 31.9 with sheep and58.8 with pigs. Kellner considers that these differences are onlypartly due to the intestinal slime, etc., containing previouslydigested nitrogen, but are in t:ie main caused by the bacteria inthe intestine which build up insoluble proteins in the fzces fromprotein matter that has previously been digested, or from non-protein nitrogen compounds in the food. The many other paperswhich have been published on nutrition and digestion questionsare mainly of technical interest and do not break new ground.49 Amer. J. Physiol., 1908, 20, 470, 477, 493 ; A., i, 115 ; Amer. J. Physiol.,1908, 22, 362, 433 ; A., i, 744, 843 ; J. Bid. Chcnz., 1908, 5, 187; A . , i, 928, 929.6O Zeifsch. p h p i o l . Chem., 1907, 54, 110; A., i, 69.51 Atti Iz. Accad. Lincei, 1908, [ v ] , 17, i, 609 ; A . , ii, 619.82 Ann. Izcport, 1907, 276. 53 Ladw. Terszcchs. -Stat., 1908, 68, 463AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 257,4 nalytical.Attention may be directed to two papers on the determinationof small quantities of nitrogen and carbon in soils by Chouchak andPouget,5* which may occasionally prove useful when only a smallamount of material is available, although it is difficult to see whatsuperiority the method for nitrogen possesses over the Kjeldahlprocess followed by an estimation of the ammonia in the distillateby nesslerising, nor does the method for carbon promise to be moreaccurate than the modified wet combustion process.65A. D. HALL.Ii4 Bull. SOC. chin&., 1908, [iv], 1, 1173, 3, 75 ; A., ii, 223, 225.Ii5 Trans., 1906, 89, 595.REP-VOL. V.