AGRICULTURAL CHEMISTRY AND VEGETABLEPHYSIOLOGY.THE year 1912 represents a period of steady progress without anyremarkable discovery or new advance to make the date memorablein the history of the science. It is perhaps hardly to be expectedthat any wide new generalisation can be attained for some timeto come. The first approximations to the truth have already beenmade, and we are a t present realising the inadequacy of theanalytical methods available to solve the very intricate questionsinvolved in all living processes. I n every direction, in thechemistry of the soil, in the nutrition of the plant and of theanimal, evidence is accumulating of the powerful effects of tracesof this or that constituent, traces which are both minute anddiEcult to identify in the complexes of which living tissue iscomposed.Perhaps the most striking example is afforded by recentwork in animal nutrition. The older investigators were concernedwith the broad quantitative facts concerning the utilisation of food-proteins to repair nitrogenous waste-carbohydrates, and fatsas sources of energy. It has now been shown, however, that ananimal may be supplied with a diet perfectly balanced from thispoint of view, pure proteins, carbohydrates, fat, and salts inadequate quantities, and will yet fail to grow or even to thriveunless a minute trace of some materials directly derived from livingorganisms, such as meat extract, milk, or fresh vegetables, is given.The amount of the latter constituent involved do not enter into thequantitative statement of the food supplied and utilised, yet theyare indispensable to the well-being of the animal.Again, in discuss-ing the chemical processes taking place in the plant, we mustadmit that we can follow no one of them accurately because of theimperfection of our analytical methods. The funda.menta1 functionof the plant is photo-synthesis and the subsequent migration andstorage of the carbohydrates produced thereby; in order to followthe sequence of this process it is necessary to estimate with accuracythe constituents of a mixture containing five- and six-carbon sugars,bioses, starch, and other carbohydrates approximating to starch,all in dilute solution and liable to change from the presence of24AGRICULTURAL CHEMfSTRY AND VEGETABLE PHYSlOLOGP.243enzymes, masked also by the presence of nitrogenous substances ofvarious stages of complexity. Until analytical methods have beenworked out capable of dealing with such complexes as this, andwith reasonable rapidity, we can neither follow the developmentof the plant nor reason about such practical aspects as its qualityor food value.Soil Chemistry.The question of the increased fertility of soils that is producedby heating to the temperature of boiling water or exposure for atime to the vapour of antiseptics haa continued to occupy theattention of investigators in all parts of the world. Russell andHutchinson have so far published no further communicationregarding their theory of the source of the increased productivity,namely, that i t is due to the destruction of a factor that inhibitsthe free development of the bacteria reducing the compounds ofnitrogen present in the soil to the state of ammonia, which factorconsists in certain forms of protozoa inhabiting normal soil; butnone of the other investigations invalidates their theory.Russell,in collaboration with F. R. Petherbridge,l has published an accountof experiments on the treatment of greenhouse soils on a com-mercial scale both by heating with steam and by the addition ofvarious antiseptics. I n the rich composts employed by marketgardeners under glass, which are constantly maintained in a verymoist condition and a t high temperatures, deterioration sets inafter a few years, and the soil has to be changed, although analysiswould still show it to be rich in all the elements of plant food.The conditions are obviously such as would favour the developmentof protozoa, but nematodes and other parasitic organisms alsoincrease abnormally and are affected by the treatment just like thsprotozoa.The authors found that such greenhouse sick soil canreadily be restored to its former condition and made even moreproductive by steam heating or by the addition of small quantitiesof various antiseptics, of which formaldehyde is the most practicallyeffective. Methods have been worked out which are commerciallyremunerative, and many of the market gardeners growing tomatoesand cucumbers are now partly sterilising their used soils as amatter of business routine.The question, however, calls for muchmore investigation, as heating t o such temperatures as loooproduces substances which persist in the soil f o r a time and areinjurious to seedlings and the earlier stages of certain plants,although not to others. The foimation, however, of these injuriousbodies is most irregular, and the results cannot as yet be predictedwith any particular soil.J. Board AgriczlEture, 1912, 18, 1923 ; 19, 809.I244 ANNUAL REPORTS ON THE PROGEESS OF CHEMISTRY.0. Schreiner and E. C. Lathropz have isolated some of thesesoluble substances that are formed in steam-heated soils. Theytook two soils of the same type, one poor and the other rich. Fromthe poor soil they obtained dihydroxystearic acid and various decom-position products of nucleic acid, namely, xanthine, hypoxanthine,guanine, cytosine, arginine, all of which substances were increasedin amount by the heating process.In the rich soil they were notpresent at the outset, but were produced by heating. The nitrogencompounds may serve as food for plants and add to the value ofthe soil, but this value is overbalanced by the detrimental effectsof the dihydroxystearic acid, which must be removed before thebenefit of steaming is realised. E. C. Lathrop, in another com-munication,3 explains his method of isolating guanine, which hasso far only been found in heated soils, probably because i t is sosubject to destruction by the micro-organisms, etc., present innormal soil. Among the most effective compounds examined byRussell and Petherbridge was calcium sulphide, to which they areinclined to attribute the fertilising value of the old form of “gaslime ” known as “ Blue Billy,” and E.Boullanger 4 finds the additionof flowers of sulphur increases the fertility of the soil. As thisincrease is not obtained with soil that has been sterilised, Boullangerconcludes that the action of the sulphur must be in some wayconcerned with the living organisms of the soil. In a furtherpaper,Q he attributes to the sulphur an activating effect upon theorganisms breaking down the insoluble nitrogen Compounds of thesoil, because only small doses are effective, further additionsreducing the fertility of the soil below the normal. A. DemolonGconsiders that the presence of free sulphur in crude ammoniumsalts from the gas works explains the manurial efficiency of thesecompounds, which is greater than can be attributed to the nitrogenalone that they contain.It would hardly seem, however, that anyvery trustworthy evidence has been produced of the activatioFofbacteria by non-nutritive substances. The whole question ofso-called “ catalytic ” stimulus of either lower organisms or plantsis still enveloped in doubt as to the facts to be explained.It is satisfactory to note that considerably increased attention isbeing paid to liming soils both in practice and in the investigationof the effects of lime on the chemical and bacteriological changesin the soil. A t one time among the most widespread of farmingoperations, liming and chalking fell into disuse with the rise inJ.Amer. Che?n. Soc., 1912:34, 1242; A., ii, 981.Ibid., 1260 ; A., ii, 982.Contpt. r e d . , 1912, 154, 369 ; A., ii, 381.With M. Dugardin, ibid., 155, 327; A., ii, 971.Cmpt. rend., 1912, 154, 524; A., ii, 382AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 245the cost of labour and the introduction of artificial manures, andit is only recently that their value, indeed necessity, on many soilsis beginning again to be recognised. In two extensive papers,0. Lemmermann, A. Einecke, and H. Fischer7 discuss the effect oflime and magnesia in various ratios on the bacterial content andactivity of the soil, and the effects that may be observed on plantsarising from either the presence or the lack of this constituent.P.E. Brown8 discusses the effect of applications of ground lime-stone up to the rate of three tons per acre on the Wisconsinexperimental plots. He finds that the base increased the numberof bacteria present in the soil; a t the same time its ammonia-making, nitrifying, and nitrogen-fixing powers had all been raised.As might be expected, the crop-producing powers of the soil hadbeen raised pari passu.E. BlanckQ has examined the laterite soils of the tropics andcompared them with the red soils of temperate countries, such asthose derived from the Permian and the Triassic formations. Hisanalysis would point to considerable similarity between the twosets of soils, although the surface of the laterite soils in proportionto the amount of silica and alumina they contain is greater,because the sesquioxides are partly in a colloidal state.D. J.Hissink10 points out that Blanck's analyses indicate a muchhigher ratio of alumina to silica in the laterite than in the redsoils, van Bemmelen having previously noted the high proportionof free alumina as a characteristic of laterite soils.As regards the study of soils in situ a survey of the soils andagriculture of Shropshire has been published by G. W. Robinson,lland contains a number of analyses, chemical and physical, of soilsderived from the Old Red Sandstone, the Wenlock Shale andother Silurian rocks, and from the Bunter and Keuper. A. D. Ha11and E. J. Russelllz report studies of the composition of the soiland of the grass growing on them of certain fields in RomneyMarsh, where some fields are capable of fattening six or eightsheep to the acre in the summer months, whereas the, land along-side, however lightly stocked, will only maintain the sheep in agrowing condition.Three pairs of such fields were studied, butdespite the great differences in their productivity, the ordinarymethods of analysis, mechanical and chemical, did not reveal anymarked causal factor which would differentiate between them. I nLandw. Jahrb., 1911, do, 174, 255 ; A , , ii, 198.Centr. Baht. Par., 1912, ii, 34, 148 ; 35, 234 ; A., ii, 670.J. Zandw., 1913, 60, 59; A., ii, 482.Ibid., 237 ; A., ii, 981.Published at Shrewsbury.J. Agric. Sci., 1912, 4, 339246 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.each pair the soil of the good and the bad field, althoughdiffering in type in the three cases studied, was similar withinthe limits of error of the method, the water content andtemperature throughout the growing season were also similar, andthe herbage neither botanically nor chemically could be distin-guished.The only constant and significant differences found werethat the good soils were slightly higher from the permanent watertable, more permeable to water, and richer in phosphoric acid,although the poorer soils could not be regarded under ordinarystandards as deficient in this constituent. The soils of the goodfields were also more active, their oxidising power and the rate a twhich they produced nitrates and ammonia were greater.Theherbage was characteristically more leafy and less steinmy on thegood fields, but the proportions of fibre and of nitrogen compounds-protein, non-protein, and digestible-revealed no significantdifferences. The general conclusions reached by the authors werethat our existing methods of analysis, both of soils and of fodder,are not refined enough to discriminate between good or bad incases of this kind.Bacteriology.One of the most important processes in the bacteriology of soilconstituents has hitherto received remarkably little attention,despite the fact that it plays a considerable part in other industrialprocesses. We refer to the fermentation of cellulose and otherinsoluble carbohydrates found in plant tissues.The broad factsthat such substances are rapidly oxidised in soil to carbon dioxide,and that humus, methane and hydrogen are possible by-products,have long been familiar, as also that the degradation process is abiological one, but the investigations of the agencies are few andincomplete. Omelianski has described two organisms which workunder anzerobic conditions and in addition to carbon dioxide, fattyacids and humus produce, the one methane, the other hydrogen,but few other investigators have continued on this line of research.K. F. Kellerman and L. G. McBeth13 have now published a pre-liminary account of a fresh attack on the cellulose organisms, whichalready leads us t o revise our conclusions on the subject, and bringsthem much more in accord with field experience.Unable to isolateorganisms agreeing with those described by Omelianski, theyobtained from him preparations of the bacteria he had described,and were able to isolate two distinct cellulose ferments from themethane-f orming, and one from the hydrogen-forming, pre-paration. All three, however, proved to be only facultativel3 Centr. Bakt. Par., 1912, ii, 341, 485AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 247anaerobes, which oxidised cellulose most readily in the presence ofoxygen. I n no case, however, did the pure culture of the organismgive rise to gas; both the methane and the hydrogen were liberatedby contaminating organisms from the products of the degradationof the cellulose.These investigators also succeeded in isolatingfrom soil eleven other organisms attacking cellulose, one of whichbelonged t o the thermophilic group. All these acted as facultativeanaxobes, and none of them gave rise to gas. Large numbers offungi were also found to have the power of dealing with cellulose.With the above exception, bacteriological investigation seemslatterly to be concerned more with the soil as a whole, with theactivity of groups of organisms bringing about a particular change,than with the work of particular organisms isolated under laboratoryconditions. The view that the ammonia-making bacteria in themain determine the formation of available nitrogen compounds,and in consequence the fertility of the soil, is gaining ground, andis strengthened by several of the researches that have been pub-lished during the year.It was long held that the higher plantscould only take up nitrogen from the soil in the form of nitrate,and after the discovery of the nitrifying organisms, it becamecustomary to regard the rate of nitrification in the soil a8 thelimiting factor in supplying the crop with nitrogen. As, however,the amount of ammonia in the soil never increases beyond verylow limits unless the nitrification organisms have been killed offby one of the processes of partial sterilisation, it becomes evidentthat nitrification normally goes on as fast as ammonia can besupplied, and that the limiting factor is the rate a t which theorganisms splitting off ammonia from the nitrogenous reaidues dotheir work, rather than the activity of the further group whichconverts ammonia into nitrates.Other evidence has shown that thenutrition of the plant by ammonia instead of nitrates takes placeto a considerable extent in the field, and is not a matter of abnormallaboratory conditions. In this connexion attention may be drawnto a paper by P. E. Brown and R. S. Smith,l4 who have beeninvestigating the bacterial activity of the soil a t different seasonsof the year, and especially after freezing has taken place. I nautumn, the number of bacteria diminishes with the fall of tem-perature, but rises again rapidly after freezing has taken place.The ammonia-making, the nitrifying, the nitrogen-fixing, and thedenitrifying power of the soil all show the same sequence, but therise of activity is most marked in the ammonia-making power.Theauthors conclude that the increase in the numbers of bacteria musttake place when the soil is frozen, but they do not seem to havel4 Centr. Bakt. Par., 1912, ii, 34, 369248 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.considered whether it may not follow very quickly on a liberationof soluble food brought about by the freezing. In dealing withplants, we have evidence that processes like freezing, by alteringthe water content of the cells, brings enzymes into play and startsor speeds up many actions which result in soluble products leavingthe cell, and by analogy one may well expect something of the samekind to take pIace in the soil, just as exposure to chloroformvapour increases the soluble constituents that can be obtained fromthe soil.P.E. Brown15 has also traced the effect of the rotation of cropson the bacterial state of the soil. He found a larger bacterialcontent and increased activity in ammonia making, nitrificationand nitrogen fixing, in soil that had been under a rotation ascompared with soil that had been continuously cropped with oneplant. The soil of plots under a long rotation again gave betterresults than that of land under a short rotation of two or threecrops only. Curiously enough, where a green crop had beenturned in there was sometimes a decrease in the nitrogen content,but this the author is inclined to attribute to the reduction of themoisture brought about by the growth and ploughing in of thegreen crop.These facts must be considered in connexion withrecent theories on the cause of the benefits due to rotations.Another interesting field study of the bacterial changes in soilis reported by R. Stewart and J. E. Greaves,lG who for some yearshave been determining the nitrates in a rich soil well suppliedwith calcium carbonate under irrigation in California. They foundthat the irrigation water increased the production of nitrates, butthe smaller quantities of water were more effective than the largerapplications. Again, the amount of nitrate varied very markedlywith the depth, and successive layers of soil, although thoroughlymoist, could contain very different proportions of nitrate.A zonerich in nitrate could be made to rise or fall in the soil, but apartfrom these vertical movements there was little or no diffusion, andno evidence that any soil solution of approximately uniform com-position, as postulated by Whitney and Cameron, was ever formed.Different crops had very varied powers of seizing on the nitrateswhen formed; lucerne (alfalfa) and oats always kept the pro-portion of nitrates and the concentration of the soil solution verylow as compared with potatoes and maize. In spring the nitratecontent of the cropped soil was higher than that of the fallow;in autumn the reverse was true, as had previously been observedby Warington and King. Vogell? has been considering thel6 Cent?.. Bakt. Par., 1912, ii, 35, 234.Ibid., 3$;115.l7 Ibid., 540 ; A., ii, 1089, 1206AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 249destruction of nitrates in the light of certain experiments in whichthe soil was placed in shallow layers in porcelain vessels. The soilcontained 15 to 20 per cent. of water, but although no freshorganic matter was present, great losses of nitrates were expe-rienced up to 60 per cent. within ten days. The reduction seemsto depend on the exclusion of air by the moisture in the littleaggregates of soil. The author suspects some purely chemicalreduction of nitrate, but the evidence against biological action doesnot seem very strong.C. B. Lipman and L. T. Sharp18 have investigated the toxiceffects of various substances, chloride, sulphate, and carbonate ofsodium, found in alkali soils, on the activity of the ammonia-forming, nitrifying, and nitrogen-fixing organisms.The nitrogen-fixing organisms, unlike those causing nitrification, are resistantto comparatively high concentrations of sodium chloride andsulphate, hence the abnormal accumiilation of nitrates observedby Headden and Sackettlg might still be due t o bacterial action.The explanation advanced that the accumulation was due to excep-tional fixation of nitrogen by A zotobacter had been criticised, notonly on the score of the absence of carbohydrate as a source ofenergy for the nitrogen fixation, but also on the ground that thechlorine in the soils increased with the nitrate to such an extentas would inhibit bacterial action, a correlation which would alsoindicate leaching and seepage as the source of both salts.J.Stoklasa 20 has studied the biological absorption of variousmanure constituents when added to soils. When solutions ofsoluble phosphates, potash, ammonia salts or nitrates are allowedto percolate through the same soil, sterilised in the one case andnot in the other, €here is always considerably greater removal ofthe fertilising constituent by the unsterilised than by the sterilisedsoil. The bacteria either utilise the material in growth and multi-plication, or arrest it in some way by temporary adsorption.Stoklasa regards the amount of absorption as proportional to thenumber of bacteria in the soil, and proposes to take it as a measureof the bacterial content, and therefore of the fertility of soil.A.Duschetschkin 21 also demonstrates the biological precipitationof phosphoric acid when solutions are placed in contact with ablack soil enriched with starch. If the soil is first sterilised, thephosphoric acid remains soluble.l8 Centr. Bakt. Par., 1911, ii, 32, 58 ; 1912, 33, 305 ; 35, 647 ; A., ii, 76, 473,l9 Ann. Report, 1911, 222; Sackett, Centr. Bakt. Par., 1912, ii, %, 81. ; A., ii,2e Chem. Zeit., 1911, 35, 1425 ; A., ii, 198.21 J. E q . Landw., 1911, 666 ; A., ii, 677.1200.670250 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Chemistry o f Plant Nutrition.It is now somewhat generally agreed that formaldehyde con-stitutes one of the early steps in the photosynthetic process wherebycarbon dioxide and water are converted into carbohydrates andoxygen.The difficulty is to isolate the formaldehyde amid themany other substances present in the green leaf. T. Curtius andH. Franzen 2 distilled large quantities of green hornbeam leaveswith water, and were able to identify very small amounts offormaldehyde in the distillate. Other green leaves when distilledalso gave positive results. They were able to isolate Aa-hexen-aldehyde from the distillate. The presence of this substance mustalso be connected with carbon dioxide assimilation, because it wasnot obtained from the same leaves if they had been kept protectedfrom the light for some time before gathering and distillation.I. Pouget and D. Chouchaks have repeated some of the earlierwater-culture experiments on the effect of the concentration ofthe nutrient solution on the growth of the plant.For each of thecritical constituents, nitrate. phosphate, and potash, they f ou udthat a t very low dilutions (for example, 0.1 milligram of P,O, perlitre) the plant gives out, and does not absorb, the constituent.As the concentration increases the absorption increases y o rntnuntil a point is reached when the absorption is exactly proportionalto the concentration of the nutrient solution. A further point isreached later when the absorption becomes less than indicated bythe increased concentration, because it is then determined by thecapacity of the plant to assimilate the material taken in. Otherunpublished experiments in England would confirm the main con-clusion of the authors that within certain limits the absorption ofthe nutrient materials and the consequent growth of the plant isproportional to the concentration of the solution, even when pre-sented to the roots in unlimited amounts.These facts afford somz-what cogent arguments against Whitney and Cameron’s soil solutiontheory, according to which the concentration of the soil water insuch constituents as phosphoric acid and potash is a matter of noaccount in the nutrition of the plant, because it can fully supplyits requirements from a solution of extreme dilution, far belowany that would be formed naturally even in the poorest soils.The method of water culture is, however, full of pitfalls, andexperiments require to be repeated in large numbers and interpretedwith great caution.E.Ramann% has continued his studies of the migration of i*ood22 Ber., 1912, 45, 1715; Annulen, 1912, 390, 89; A , , ii, 797, 978.23 Compt. rend. , 1912, 154, 1709 ; 155, 303 ; A . ) ii, 796, 975.Landw. Yersuchs. $tat., 1912, 76, 157, 165 ; A., ii, 378AGRlCULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 251substances from the leaves of trees prior to the autumnal fail.He finds that the migration chiefly takes place during the com-paratively short period after the leaves have begun to changecolour. Then a considerable proportion, in some cases amountingt o one-half, of the nitrogen and phosphoric acid are returned t othe permanent parts of the tree, calcium compounds and silicataking their place. If the leaves are killed by frost before’thsyhave yellowed off and died naturally, the migration process isstopped, and the nitrogen, a t any rate, remains in the leaves.Theanalyses indicate, strangely enough, that in such cases the frozanleaves lose their potash and phosphoric acid in a few hours afterthawing, although no rain has taken place, but such a conclusionrequires further experimental support.The question of migration also enters into the practical problemof determining the optimum time a t which to cut the hay crop,which has again been taken up by C. Crowther and A. G. R U S L O ~ . ~ ~They cut “seeds” hay on four dates separated by approximatelyfortnightly intervals, and determined the total weight of the crop,its composition, and digestibility, as far as was possible by labora-tory methods.The dry matter and the true protein per acreincreased the later the cutting, but the “amides” decreased inpercentage and finally in absolute amount. The fibre and pentosansincreased both relatively and absolutely; the soluble carbohydratesshowed some absolute decrease in the latter two cuttings. Thevalue of the food produced per acre, either for maintenance orproduction, reached its maximum a t the third cutting, and thenfell off, but the results would indicate that a fair amount oflatitude may be allowed in the date of cutting without causingappreciable loss. It would be desirable to have these resultsrepeated on a larger scale, and accompanied by real digestionexperiments.The effect of traces of various metals on the growth of plantscontinues to be a subject of considerable investigation, especiallyin France, where the labours of G.Bertrand and his colleagueshave considerably advanced the question, especially in connexionwith manganese. Several recent papers 26 deal with the dependenceof Aspergillus niger on manganese and zinc in the nutrient sub-stratum. The conclusions are somewhat remarkable-that suchminute traces of manganese as one in ten thousand million havean appreciable effect in increasing the yield of Aspergillus, althoughgreat precautions have to be taken to free the materials frommanganese in order to realise this result experimentally. Again,25 J.Agm’c. Sci., 1912, 4, 305.36 G. Bertrand, Compt. rend., 1912, IM, 381, 616 ; M. Javillier, i b i d . , 383 ; A.,ii, 377252 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.in the absence of manganese, the fungus will not give rise toconidia; moreover, minute traces of iron and zinc must also bepresent before the conidia will form. A minute trace of zinc mustalso be present in the medium to enable the invertase present inthe cells of Aspergillus niqer to act; in its absence the invertasedoes not diffuse through the cell waII.The employment of manganese and other so-called ‘ I catalytic ”manures on a field scale does not make much headway. T. Pfeifferand E. Blanckfl report a number of experiments both in potsand with trial plots in the field.The results are not conclusive,however, only in so far as they indicate that the magnitude ofthe effect produced by the manganese, if any, is not of practicalimpor’tance. A. J. Brown and F. P. Worley28 have continuedtheir investigation into the extremely interesting semi-permeablemembrane they discovered enveloping the endosperm of barley.They now find that the rate of absorption of water by the barleyseeds a t different temperatures is an exponential function of thetemperature. This leads to a discussion of the constitution of waterthat would agree with such a result, from which the authorsconclude that only the simple molecules are transmitted by thedifferentia1 septum and assimilated by the starch within. Thisconclusion is confirmed by the measurements obtained for the waterabsorbed from a solution of ethyl acetate, which agree with theresults obtained for pure water, except for a possible slight associa-tive effect of the ethyl acetate on the water molecules.Chemistry of Animal Xutrition.29The most notable example of the effect of certain substancesexisting in food in minute traces only is afforded by the numerousinvestigations that have led to the discovery of the source of thedisease of malnutrition well known in the East under the nameof “beri-beri,” which has been shown to be identical with a stateof polyneuritis that can be induced artificially in fowls a d otheranimals.Beri-beri is prevalent in rice-eating communities, andvarious theories have been previously advanced to explain its origin ;for example, it has been associated with a fungus attacking ricethat is stored and allowed to become mouldy, and, again, it hasbeen attributed to the incomplete nature of the proteins containedin rice.It was noticed that many rice-eating communities, oftenof the poorest character, were free from the disease, whereas othersconsuming purchased rice of presumably good quality developed21 Landw. Versuchv. Stat., 1912, 77, 33 ; A., ii, 476.28 Proc. Roy. SOC., 1912, B, 85, 546 ; A., ii, 1086.29 See also pp. 228 et seqAGRICULTURAL CHEMlSTRY AA’D VEGETABLE PHYSIOLOGY. 253cases of the disease. The next step was the observation that fowlsfed on decorticafed or polished rice pine away and contract adisease of polyneuritis similar to and presumably identical withberi-beri.30 If, however, the fowls are fed on whole rice just asit is threshed, they remain healthy; the same diet, also, willinduce recovery from the disease induced by the decorticatedmaterial. A t this stage several lines of investigation coincide.U.Suzuki, T. Shimamura, and S. Odake31 proceeded to attackthe husk or the polishings removed in the process of preparingrice for market. These investigators satisfied themselves that thesubstance inhibiting the disease could be extracted from the husksby water or alcohol. Finally, by dealing with the alcoholic extractof the fat-free husks, they were able to prepare an alkaloidalsubstance containing nitrogen, to which the name of oryzanin hasbeen given.Small quantities of this substance will keep animalsfree from the disease that follows feeding on materials in whichit is lacking; for example, dogs fed on boiled meat and huskedrice after three or four weeks completely waste away and die ifthe diet is persisted in. The addition to the daily ration of 0.3gram of oryzanin, however, brings about a rapid recovery. Thesame investigators were able to show that the same substance, orone analogous in its effects, could be isolated from extracts of wheatand barley bran, from bread, from oats, cabbages, and othernatural foods. Similar experiments have been reported with wheatbran; the white flour from the interior of the endosperm has incertain cases proved incapable of maintaining growth, although itwas thoroughly utilised on the addition of a small quantity of thebran or its extract.To test the applicability of these facts to thenutrition of man on white or on so-called (‘ standard ” bread, L. F.Newman, G. W. Robinson, E. T. Halnan, and H. A. D. N e ~ i l l e 3 ~made experiments on themselves, each trial of one or other breadlasting a week. On the whole, absorption of the nutrients was veryuniform; from white bread about 34 per cent. more protein wasabsorbed, whilst ‘‘ standard ” bread contained rather morephosphates, which were equally well absorbed. When whole-mealbread containing more of the husk was fed, the absorption both ofnitrogen and phosphorus compounds was less. There was noevidence of any effect due to the specific cortex compounds, norcould the usual claims made for “standard” bread be substan-tiated.Indeed, the differences indicated possess no practicalimportance except when bread becomes the chief, almost the only,article of diet.30 See also L. BrBandat, J. Pharm. Chim., 1911, [vii], 4, 447 ; A., ii, 64. ‘‘ Biochein. Zeilsch., 1912, 43, 89 ; A., ii, 980.32 J. Hygiene, 1912, 12, 119 ; A., ii, 658254 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The capacity of a given food to bring about live weight increasemust, however, be distinguished from the power of merely main-taining equilibrium without growth, and this, as regards theproteins, is well brought out in several American investigations.For example, E. V. McCollums fed pigs with the so-called incom-plete proteins, zein and gelatin. For maintenance purposes,to repair the daily wear and tear of nitrogenous tissue, thepigs could utilise these proteins very effectively, up to 80 percent. with zein and 60 per cent. with gelatin, but for growth andthe formation of additional body tissue they possessed much lowervalue. The author therefore insists on the distinction betweenthe prohins required for growth and those needed for maintenanceonly.The discussion on the utilisation of the various nitrogen com-pounds can be paralleled by the question of the form in whichphosphorus compounds must be present in the food in order to beutilised. Most plants contain organic phosphorus compounds, andthe question is whether such substances are necessary to the animalor can be replaced by inorganic phosphates. Experimenting withgoats, Fingerling 34 finds that deficiency of organic phosphortlscompounds 3n fodder can be repaired by the addition of calciumand other inorganic phosphates. The matter is of some practicalimportance in the feeding of milch cows and young stock, certaindiets being deficient in ash containing phosphates.A. D. HALL.33 Amer. J. Ph,ysiol., 1911, 20, 215 ; A., ii, 63.34 Riochem. Zritscih., 1912, 39, 239 ; A . , ii, 465