TT,GETAULE PHYSIOLOGY AND AQRICELTURE.Chemistry of Vegetable Physiology and Agriculture.75Nitrogen necessary for Cultivated Plants. By THAER (Bied.Centr., 1884, 546--549).-The author in 1879 reported to R congress ofnnt~uralists a t Freibury, as the result of eleven years' experimerlts, thatthe nitrogen contained in the crops on which lie experimented, grownon sandy loem, was derived from the soil, t o half its amount. He hascontinued his experiments since then on potatoes, rye, barley, andpeas, and now arrives a t the conclusion that tbere is an unmistakablerelation between the quantity of nitrogen supplied by the soil and thatput into it by man.If man supplies nitrogen freely in t,he manure, nature respondsfreely in the crop ; if man is sparing, so is nature ; and he formulatesthe rule that in a year of fairly productive weather, if the farmersupplies in the form of manure one-half the nitrogen which he oughtto receive from the crop, that nature will supply the remainder. Heexcepts specially adverse seasons when, for example, exceptionaldryness prevents decomposition of nitrogenous substances ; in suchcases, sulphate of ammonia and Chili saltpetre, if used, are a completeloss, as they are never available after the first year.J. 1'.Formation of Sugar in Beets. By A. GIRARD (Bied. Centr., 1884,545--.546, and CYowpt. ?wL(/., 99, 808).-The author being of opinionthat light takes a very great part in the production of cane-suger inthe beet, undertook a series of experiments, extending over severalmonths. He had leaves gathered daily about four o'clock in the after-noon and three in the morning, and analysed them ; he found that theleaves gathered after the enjoyment of the whole day's light invari-ably contained considerably more cane-sugar than those pluckedafter passing through the night, the amount in the former being inall cases more than double that of the latter ; the glucose and reduc-ing sugars did not vary in anything like the same proportion.Heconsiders the leaves t,o be the place where the sugar is formed, fromwhence it passes t o the roots, and that a double process of osmose iscontinually being carried on within the cells of the plant, one carry-ing the mineral matters derived from the plant t o the leaves, theother bringing the completed saccharose to the Foots.Tollens agreeswith him in this view, which he says has long been accepted as true.In a paper recently published in the Conzptes renclus, the authorgives additional experiments confirming these results.Salicylic Acid in the Cultivated Pansy. By A. B. GRIFFITHSatid E. C. COXKAD (C'ILL'IIL. A-ews, 50, 10d).--Various pnrt,s of theJ. F7 6 ABSTRACTS OF CHEMICAL PAPERS.garden pansy were found to contain the following percentage of sali-cylic acid :-I. 11.Leaves ............ 0.1329 0.1 930Stems 00852 0.0856Roots.. ............ 0.0531 0.0521,..............D. A. L.Experiments with Manures containing Thiocyanates. ByG. KLEIN (Bied. Csntr., 1884, 519-520).-Three plots mere sown withbarley and oats, one remained unrnanured, the second was manuredwith ammoniacal superphosphate, the third was manured with thesame, receiving in addition 0.8 per cent.of ammonium thiocyanate.In the last plot, the plants were developed slowly, and the points ofthe leaves became brown ; this lasted two weeks, when rain came on,and the plants recovered their normal strength and appearance, andthey flourished as well as those in the other plots ; evidently the rainhad caused decomposition of the thiocyanate. With water culture, thenulritive liquid used contained 0 . ~ 1 gram of ammotlium thiocyanate tothe litre; old plants with six to eight leaves bore this without injury, butwhen the quantity was doubled they sickened a t once, and 0.1 gramper litre proved fatal almost immediately.In view of the decidedlypoisonous effects of the thiocyanate, the author cautions farmersagainst using manures containing it.Poisonous Effects of Ammonium Thiocyanate on Vegetation.By J. K ~ N I G (Bled. C‘entr., 1881, 520-522),-Foar flower-pots werefilled with loamy soil, each was manured with 8 grams ammoniacalsuperphosphate. No. 1 was left so, No. 2 received 0.05 gram, No. 30.10 gram, and No. 4 0.25 gram of ammonium thiocyanate; theywere put aside for five weeks, a t the end of which No. 1 had aplentiful crop of weeds; No. 2 only a, few, and the other t w o none.‘The weeds were removed, and the pots sown with barley and oats.The growth was good in all of the pots, and the pots containingthiocyanate surpassed the others, owing probably to the excess ofammonia and deconiposition of the thiocyanate.Similar experimentswere made, sowing milnure and seeds together; the results weresimilar, and were confirmed by others in which the plants werewatered n-ith solutions containing varying quantities of thiocyanate.The author csutioiis buyers of manures apainst the use of certainsuperphosphates now being actively pushed, and if they are usedadvises them to be sown some days before the seed; if possiblerainy weather should intervene.J. F.J. E’.Influence of Acid Smoke on Vegetation. By J. v. SCHROEDERand another ( R i e d . Ce7~tr., 1884, 555-556).-The damage done togrowing plants by smoke containing acid gases shows itself first by theleaves becoming yellow or yellowish-brown and spotted-in leaves ofthe pine family the points become yellow.Such parts on analysisyield larger proportions of sulphuric or hydrochloric acid, as the casemay be, than the healthy leaves. Schroeder says that 5.L$ab of sulVEGETABLE PHTSIOLOGY AND AGRICULTURE. 57phurous anhydride in the air will quickly injure plants, but plants areriot so sensitive t o hydrochloric acid. The most sensitive to snlphurousgas are conifel-011s trees, the least so agricultural plants and vegetables.Fruit trees are very liable to damage, plums and cherries more sothan apples o r pems.The author made a large number of analyses of affected trees inthe neighbuurhood of four different fqctories, in t w o of which zincblende was roasted, a bronze foundry, and a general chemical worksfor producing sulphuric and hydrochloric acids, chloride of lime, &c.;he found that all the plants whose leaves showed they had beenattacked, contained throughout their substance more of the acidsthan healthy plants. To meet the suggestion that the supplycame from the soil, he made several examinations of it also, theresults of which confirm his views. On examination of the ash forcarbonic acid, less was found than in healthy plants; the authortliinks it proved that the acid gases penetrating from the exterior tothe interior of the plant neutralise the inorganic and organic basesnecessary to growth, and substitute those of a hurtful character.J. F.Use of Copper Sulphate to Destroy Mildew.By A. PERREY(Compt. r e n d . , 99, 543--545).-When vine poles are steeped in Rstrong solution of copper snlphate, and vines of from four to sixyears old are carefully trained round them, the vines are protectedfrom mildew (Peronospoyn viticokn), but the efficacy of the coppersulpliate does not extend beyond a cylindrical space 0.2-0.25 metrei n diameter, having the vine pole for its axis. C. H. B.Carbon Bisulphide in Aqueous Solution as a Remedy forPhylloxera. By E. PELIGOT (Conzpt. rend., 99, 587-Nl) .-Theauthor confirms Ckiandi-Bey's observations respecting the an tjsepticproperties of carbon bisulphide. He finds that when carbon bisul-phide is briskly agitat,ed with water a t the ordinary temperature,100 C.C. of water dissolve 0.3: c.c., or 0.452 gram of carbon bisul-phide.The solution has no action on lead paper, but when boiled1-upidly for some t i m e it gives off its carbon hisnlphide, and the con-densed water contailis small quantities of hydrogen sulphide. Theauthor recommends the application of an aqueous solution of carbonbisulphide to vines instead of the liquid itself.Protective Influence of Growing Plants on the Undergrowth.By E. WOLLKY (Bird. Centr., 1884, 550--551).--The distribution ofwater in the soil, and the temperature, depend very much on whether itis in a state of cultivation or not; in fallow ground, the higher strata arethe drier, and the lower the more moist. When covered by vegetation,the contrary is the case, as the roots of the plants withdraw moisturefrom the subsoil, and the leaves, fruit, &c., of the growing plantspr,ltect the upper layer from the drying influences of sun and wind.Small seeds tyhich are near the surface fare badly in fallow ground,but when sown where they are protected by vegettction they growwell. As soon as their roots reach the lower layers occupied by theC.H. B78 ABSTRACTS OF CHEMICAL PAPERS.roots of the covering plants, these must be removed, as well onaccount of the exhaustion of moisture as of excess of shade.J. F.Four-course System at Woburn. By A. VOELCKER (Bled. Centr.,1882,623-626 ; Jour. A y i . Xoc., 19, 348--35ti).-This report refers tothe seaqon 1883, and is an account of experiments conducted in thesame manner as has been previously reported on and referred to inthis Journal.The highest yield of purple top swedes was obtainedfroni the plot (plot 3 ) manured with farmyard manure of knowncomposition mixed with Chili saltpetre, bone-ash, superphosphate,and snlphates of magnesium and potassium, the lowest yield(plot 1) from the plot which had received farmyard manure(cotton cake added to the food); on the second plot, grew Dutchwhite clover, and it was fed off by sheep which on plot 1 receivedalso cotton cake, and on plot 2 maize-meal ; the sheep on plot 1 in-creased in weight the most rapidly of all the flock, and this greaterincrease is due to the cake. The clover on 3 was of least value, theaction of the saltpetre showing itrelf by diminishinp the value ofthe succeedinq season.The wheat was lowest on plot 3, but thestraw was highest; bnt the barley was highest of plot 2, which hadreceived only farmyard manure made with maize-meal. E. W. P.Growth of Breadstuffs in Various Latitudes. (Rid. Centr.,1884, 626--628.)-In Europe, barley (and potatoes) can be grown asf a r north as 70". but, east and wedwards the limit, falls southwards.In the Faroe Islands (61-43") but little grain is grown, whilst inGreenland and Iceland none a t all. I n East America the limit is SO",which rises to 57--'43" on the western coast, whilst on the east coastof Asia it again sinks to SO", gradually rising to 60" (Obi river.), 67"Archangel, and finally i n Sweden to 70". I n the southern hemi-spheres, the regions of limited growth are not ascertained.Thelatitude does not wholly determine the limit, height above the seamust also be taken iiote of. I n Sweden, cereals will not grow a t aheight above R few metres, whilst in Switzerland they flourish at, aheight of 625-1250 metres ; wheat requires a higher temperaturethan rye or barleg, oats require least warmth. There are many dis-tricts in the Alps were by reason of the cold no winter corn can besown, yet the summers are hot enough for maize to grow well. I nthe Himalayas, maize is grown a t 933 metres, wheat a t 3125 metres,barley, oats, and rye a t 3750 metres, and in Thibet wheat ripens a t5625 metres. The chanqe in the temperature IS remarkable. Pro-ceeding eastwards, wheat again hecomes more nitrogenous, which factis accounted for by the harder winters, the hotter summers, and thesmaller amount of rain than is experieiiced in Europe.The followingfigures represent the percentages of nitrogen in several samples ofwheat :-Scotch, 2.01 ; North of France, 2.08 ; Lille, 2-18 ; Chemnitz, 2.42 ;Bavarian, 2.20 ; Eldena, 2.18 ; Moraviau, 2.36 ; Polish, 2-68 ; Odessa,3.12 ; Tayanzog, 2 54 ; Rjgsan, 2.47 ; Samaya, 3.47 ; European Russia,3.58 ; Wilna, 1.95 ; Cedtrilt Provir~ces, 3.57 ; South-eastern Provinces,3-72 ; Siberia, 2.65 ; Tobolsk, 2.74. The nitrogen in rye and barleTWGETABLE PHY SIOLOOT ASD AGRICULTURE. 79also varies : Scotch rye, 0.90; German, 2.12 ; Scotch barley, 1.42 ;Cultivation of two Varieties of Sorghum, and Preparation ofSugar therefrom.By V. PFUEL and another ( B i e d . Centr., 1884,628-GW) .--HO~C?LC sorghum and H. sacch.nratum were sown thin and011 the flat ; the method of cultivation is the same as for niaizP, and afterautumn cutting it throws u p a good feed for sheep. As regards thevalue of t,his crop as a source of sugar, i t has been found t,hat a t theperiod when the seed ripens there is 15 per cent. of saccharose present ;before that time the qnantity is only 1-3 per cent. That the yieldof sugar may be as high as possible, the rows strould be 4 feet apart,the seeds (six together) one inch deep, and each plant left a t 4 to 6inches apart from its neighbour. The rows should run north andsouth, and the land be kept well hoed until the plants are 3 to 4 feetCultivation of Sorghum in France. By N.MINAKGOIN (Bied.Certtr., l884,634).-The cultivation of sorghum is less costly than thatof beet, and the yield of molasses is less. By the use of Champonnois’apparatus, good brandy can be prepared, and the residue makes goodfodder, but the brandy must be .thoroughly rectified, which can beaccomplished without difficulty.Drying of Diffusion Cuttings. By M. M~RCKER and others(Bied. Cei~tr., 1884,630-632).-Hellriegel states that i t is advisable todry these cuttings thoroughly ata high temperature, after which theyahaorh but a relatively small amount of moisture, and keep better.Marcker thinks that the digestibleness is impaired by the high heating ;he also recomniends $ per cent. of lime to be added, and then pressureapplied before drying ; this prevents swelling, and renders thepressing more easy of accomplishment. Cunze and Stammer considerthat, this addition renders the fodder unpalatable ; moreover, thisper cent.is equivalent to 10 per cent. of calcium carbonate when thesections are dry. Marcker, on the other hand, says cattle eat thefodder with vigour, and that the lime only amounts to 4.4 per cent.,as part is removed by pressing-of the remainder 1.1 per cent. onlyis as carbonate, the rest being present as organic salt ; also clover-hayfrequently contains 3 4 per cent. of lime. Marcker gives the lossof organic matter occasioned by his process as 5-32 per cent.Bavarian, 1.72. E. w. P.high. E. w. P.E. W. P.I!!. w. P.Tobacco Culture.(Hied. Centr., 1884, 5Fi2.)--This paper containsnotes relative to the growth of tobacco in Gnadenthal, Switzerland.Three descriptions are cultivated-Virginia, Maryland, and Cuban.It is found that a soil rich in humus gives good results ; heavy soilsyield greater weight, but inferior quality; newly broken, warm soilproduces fine, nicely perfumed leaves. As the roots do not penetratethe soil deeply, the condition of the subsoil is not of much importance.Ttle best irianiire to use is well rotted, easily assimilable, strong cow-dung ; fresh horse and cow-dung mitke the tobacco sharp, heavy, andbititig. Irrigation with liquid manure is also advised. J. 880 ABSTRACTS OF CHEMICAL PAPERS.Influence of the Weather on Crops. By C. FERRARI (Bied.Cemtr., 1884, 589).-Rcgarding wheat, rye, and barley, the crop isless the more cloudy are the months March to June, the greaterthe number of wet days during spring, and the lower the temperatureof April to June.FrGm data collected in the valley of the Po, tjhecrop on irrigated rice fields is higher when the skies in July andAugust are unclouded; maize yields best when the summer isshowerg. During 1880, and by reason of the cold winter of 1879-80,the crop of grapes was reduced 75 per cent. when the mean wintertemperature was -40°, and the reduction is 50 per cent. when themean temperature is - 2". E. W. P.Dependence of Cultivation on the Depth of the Soil. ByHEINRICH (Bied. CerLtr., 1884, 591-593) -Vegetation is largelydependent on the state of concentration of the plant-food in the soil ;the fertility of the soil is not a t all measured by the total quantity ofnourishment present, for a deep soil may contain the same absolutequantity of plant-food as a shallow one, but there the concentrationis much lower.Consequently, if there is a want of manure, the soilmust be cultivated shallow, so as to keep up the concentration,nnd deep cultivation without a corrcsponding increase in manure isprejudicial to the yield ; deep cultivation, however, ensures thewelfare and certainty of the crop during hard weather, but a t theexpense of the yield.Influence of Physical and Chemical Properties of the Soilon Evaporation. By C. ESER (Bied. Centr., 1884, 505-519).-Although the amount of moisture in the soil depends greatly onmeteorological conditionfl, yet its physical and chemical state exercisesmuch influence, and as this is capable of arbitrary alteration, it is amatter of much practic(L1 importance.The author has therefore nladean exhaustire series of experiments with soils of various composition,details of which accompany the paper. The general conclusions a twhich he arrives are as follows :-The amount' of evaporation of a soil depends principally on theamount of water contained when thoroughly wet. All soils appear toyield aqiieous vapour a t the same rate. Evaporation proceeds so longas the upper layer of soil continues moist, the loss being repaired bycapillary attraction from the subjacent layers. When capillary attrnc-tion ceases to act, the upper layer dries, and evaporation ceases.This drying diminishes the effects of the ordinary agents of evapora-tion, wind, &c., and if the upper layer be broken up mechanically itinterposes a still deeper shield between the moist snbsoil and thedrying influences of the atmosphere ; the same effect is produced bya top dressing, or covering of the soil.The phvsical state of thesurface is also of great importance, the evaroration from a lumpycoarse surface being considerably greater than from a smooth and well-tilled one, but a too finely powdered soil yields water more readilythan that which is in a moderately gra,nnlnr state. Under naturalconditions, soil containing humus dries quickest, sand slowest, andclay stands intermediate.The amount of evaporation is greaterE. W. PVEGETABLE PHYSIOLOGY AND AGRICULTURE. 81in proportion as the surface soil is dark in colour ; when there issubsoil-water, the amount of evaporation depends on the thickness anddensity of the intermediate layers of earth. The position of the groundalso affects the question, land exposed to the south losing most. Theangle at which ground rises from the level is also important, theloss of moisture being nearly in proportion to the inclination.Influence of the Soil and its Cultivation on the Tempera-ture of and Moisture in the Air. (Part I.) By E. Womm( Bied. Cent?.., 1884, 58%-588) .-Employing thermometers, the bulbsof which were protected from direct radiation by conical paper shades,suspended at different heights over various classes of soils, the authorfound that the air over quartz sand was the warmest, followed by darkyellow clay, then chalky sand, and lastly peat ; but that the surface ofthe peat was the warmest, then the quartz sand, clay, and chalky sand.The probable cause for the higher temperature of the peat, whilst theair above it is cooler, is the amount of moisture which it retains, butwhich, when evaporated, removes much heat, On the other hand,the light-coloured quartz sand reflects much heat ; consequently theheat absorbed and employed to evaporate the water is at a minimum,and the heating of the air is the most intense.Chalky sand beinglight-coloured reflects much heat, but much water is also retained ;therefore much heat is retained, and the air temperature falls close tothat of the air over the peat.Generalising, we have-soils which arelight-coloured and dry commu~iicate most heat to the air, whichis reduced when the soil is moist; the minimum of the air tempera-ture is reached when the soil is dark-coloured, and the heat renderedlatent by water. Another set of experiments was made on bare soil,and on soil carrying C ~ O F ~ ~ P , the heights of the thermometer above thesurface being 58 cm., 90 cm., and 200 cm., and the results were :-(1) that the air over a field bearing a crop is cooler than it would bewere there nothing growing ; (2) the variation of temperatures underthe first conditions is less than under the second. The first resultis brought about by the fact that so much heat is absorbed for theevaporation of the water by the leaves, and direct insolation of thesoil is prevented ; moreover the absorptive capacity for heat exerted byplants is much higher than that of the stones on the surface.Whenthe plants were moistened, the temperature fell below that of the airabove the same class of plant which was kept dry.To observe the influence of orientation, a pyramid of earth (4 squaremetres) was constructed, the four faces of which were directed respec-tively to the four cardinal points, at an angle of 30" to the horizon. Aswas to be expected, the air over the southern side was the warmest,over the northern side the coldest, whilst the western was warmerthan the eastern in the evening, and vice uersd.Result of Removing Debris from the Surface of Sandy Soil.By E.RAMANX (Bied. Centr., 1884, 59&596).-The soil under obser-vation was sandy, and was covered with the dead needles of pine treesgrowing on it. A plot from which these needles were regularlyremoved by a rake was compared with another kept in its naturalFOL. m v m .J. F.E. W. P.82 ABSTRACTS OF CBEMICAL PAPERS.state. The second plot was covered with moss and coarse grass,these had been removed from the experimental plot ; as regards themoisture present in both plots, it was only in May that the unrakedplot was the moister, whilst during June to September the raked plotcontained most water down to a depth of 80 em. ; this is because, asthe year proceeds, the surface becomes more thickly covered by theleaves which, together with the moss, prevent the penetration of therain.By keeping the surface of this class of soil bare a considerableloss of mineral matter occurs, by reason of the rain falling on the baresurface, arrd carrying with it much soluble matter into the lower strata ;whilst at the same time decomposition of the silicates proceeds morerapidly than in the covered soil, because of the greater variation ofheat and cold. This statement is in opposition to that of otherobservers on the same subject, but in support of his theory the authorstates that there is 4.6 percent. of insoluble mineralsin the undisturbedsoil, whilst in the raked soil there is 3.6 per cent, ; also there is a greaterloss of sulphuric acid and potassiizm.Moreover, as he finds that thereis more nitrogen removed in the rubbish than is accounted for by theloss experienced by the soil, he considers that this class of soil canabsorb nitrogen from the a i r ; the quantity of total solids removedfrom the surface is much less than what is lost by solution in thewater passing through. E. W. P.Fine and Coarse-grained Superphosphates. By F. FARSKY(Bied. Centr., I 684, 601-604) .-In his earlier communications(Abstr., 1882,90, 550,653), Farsky found that sometimes fine-grained,at others coarse-grained superphosphates were most satisfactory. I nthese experiments, he has attempted to decide the question by experi-ments made under glass, giving in addition to the superphosphate,sodium nitrate, and watering the plants (buckwheat) once and fourtimes a day ; the result thus obtained was in favour of the fine super-phosphate and the more frequent watering.I n another series, thesodium nitrate was replaced by ammonium sulphate, and the water wasgiven (1) in four equal quantities during the day; (2) one half in themorning, the other half in the afternoon ; (3) one quarter morning andthree quarters in the evening ; (4) the same quantity as in the previousexperiment, but given after the soil was much dried. It was found thatthe regular watering was best on plots manured with the finely dividedsuperphosphate, whilst the irregular watering was more adapted for thecoarse-grained manu re. On the whole, the finely divided superphos-phate is to be recommended for agricultural purposes.E. W. P.Action of Soluble and Insoluble Phosphates. By A. VOELCKER(Bied. Centr., 1884, 599; Jour. Roy. Agri. Xoc., 39, 357).--This isthe report of the action of the above manures on the experimentalplots at Woburn, during 1880-81-82-53, i.e., during a whole rotationunder the four-course system. The report in 1880-81 has already beenreferred to in a previous volume, and as the clover in 1882 failed, wehave only to remark the results obtained in 1883, when the crop wasoats. The best yield was obtained on that plot previously manuredwith Redonda phosphate, which gave the worst results in 1881 ; disVEGETABLE PBY SIOLOGY AND AGRICULTURE. 83solved and raw bone-meal is advanta'geous, and the plots producedmore than the unmanured plot ; the lime plot ranks high, in all pro-bability because of the paucity of lime in the soil (I per cent.).E.W. P.Superphosphatic Gypsurn as an Absorbent of Ammonia.By E. HEIDEN (Bied. Centr., 1884, 606) .-Coprolites from Helmstad tand Goslar were treated with sulphuric acid, the resulting solublephosphate pressed out, and the residue again treated with acid ; theresidue now consisted of calcium sulphate, with 4-5 per cent. 8olublr,and 1-2 insoluble phosphate. Compared with other ammoniumabsorbents as to its action on farmyard manure containing 0.2 percent. of ammoniacal nitrogen, it was found to be vastly superior.E. W. P.Employment of Potash Manures in Brittany.By G.LECHARTIER (Oompt. rend., 99, 658--661).-The crops grown on thereclaimed soils of Brittnny after the application of phosphatic manure,rapidly use up the reserve stores of potassium compounds in the soil,and although the grmitic rocks fi-om which the soils have been formedcontain a notable proportion of potassium, the latter can only bebrought into an assimilable form by continual tillage and exposure tothe atmosphere. I t therefore becomes necessaSy to employ manuresrich in potassium compounds, and the use of such manures is attendetlwith highly beneficial results, especially if they also contain phosphatesand nitrogen. C. H. B.By MXRCKER (Bied. Centr., 1884,607-609).-With the exception of potassium sulphate on good loam,which raised the percentage of starch 3.5 per cent., all other potashmanures depressed it 1.5 per cent. ; nor was a good result obtained withthese manures (kainite, kieserite, &c.) as regards total yield. Thisstatement, however, only applies to spring manuring, for potassiumsalts, especially on light soils, are necessary for potatoes, but they mustbe applied at some other period than the spring. The effect of potas-sium salts on the nitrogen is remarkable ; they raise the total nitrogen,but the percentage of albumino'id nitrogen is lowered, the amidq-nitrogen being correspondingly raised, pointing to the conclusion thatthe manured tubers were less ripe than the unmanured, but whethcrthis retardation of ripeness was occasioned by the potassium, by thechlorine, or by the magnesia present, is not as yet proved.Potash Manures for Potatoes.E. W. P.Sulphuric Acid as Manure. By F. FARSKY (Bied. Centr., 1884,642).-A plot manured with a compost t o which sulphuric acid hat1been added, was less productive than another but unmnnured plot.This result was probably due t o free acid in the compost, as shoti-11by analysis, E. W. Y