TECHSIC AL CHEMISTRY. 127T e c hn i c a1 C h em i s try,Influence of Coal-dust in Colliery Explosions, By W. GAL-LOWAT (Proc. Roy. Xoc., 33, 437-445, and 490-495).-A continua-tion of the author's experiments.. The apparatus finally adopted toinvestigate the influence of coal-dust consists of (1) an explosionchamber 6 feet by 2 feet, lined with strips of wood, with three open-ings for admitting the fire-damp, letting out t'he air displaced, andfor igniting the mixture respectively. It is provided with a smallcentrifugal fan for mixing the air and the fire-damp. (2.) A gallery126 x 2 x 2 feet, consisting of seven pieces, each 18 feet long,placed end to end and hooped by iron bands, one side of which, ofdimeiisions 18 feet by 2 feet 3 inches, can be opened like a door.Before an experiment, these doors are opened and coal-dust strewed onthe floor t o a thickness of one-eighth t o a quarter of an inch, andsome laid on shelves in the several sections.The method of procedureis as follows :-The explosion chamber is drawn back, and severalsheets of paper inserted between it and the gallery t o act as adiaphragm; the chamber and gallery are then bolted together, thefiredamp introduced from a measuring cylinder, and mixed with theair by the aid of the fan, and the mixture exploded. When no coal-dust was introduced, or the floor or shelves damped, the fire-dampexplosion travels along the gallery for about 12 feet; if the coal-dust was dry, and all the sections closed so as to make the gallerycontinuous, the flame extended to 50 or 60 feet (experiments showedthat the greater or less moisture in the atmosphere exerted an nppre128 ABSTRACTS OF CHEMICAL PAPERS.ciable effect on the coal-dust), and finally if the doors and the fourthand fifth sections mere opened, the flame reached to 60 or 70 feet.I nall cases, a thick cloud of coal-dust and air was driven by the explo-sion-wave through the gallery, and on emerging into the open airassumed large proportions, and exhibited all the phenomena ofincipient explosive combustion. Crusts of coked coal-dust werefound on the shelves the farthest removed from the explosionchamber, which corroborated the hypothesis proposed in connectionwith explosions a t collieries, that these crusts are deposited during a,retrograde movement of the air, travelling back towards the origin ofthe explosion. From observations made by the author a t the Peny-graig Colliery after an explosion, similar crusts of coked coal-dustwere found deposited in a direction opposite to that of the explosion.The results of the experiments given in the papers confirm theview put forward by the author as to the manner in which theflame of an explosion is originated and propagated, but they furthershow that the presence of fire-damp is unnecessary, provided that thescale of the experiments be large, and the coal-dust be sufficiently firieand dry.V. H. V.Water of Rangoon. By R. ROMANIS (Chern. News, 46, 187).-Inthe water st,ored in reservoirs a t Rangoon, thn vegetation increaseslargely during the hot season, but the quantity of free ammonia ishighest during March.Albumino’id ammonia sometimes reaches ashigh as 0.82 in July, the minimum quantity during two yearsBy A. H. ALLEN (Chem. News, 46,145--146).-1n a recent trial (J. J. Milnes against the HuddersfieldCorporation), the question arose as to the influence which the presenceof sulphuric acid had on the intensity of the action of water on lead ;and from the scientific evidence given it was inferred that a trace offree sulphuric acid was rather beneficial than otherwise, as it wouldtend to protect the pipes from the action of the water by depositinginsoluble lead sulpbate. The author has proved this suggestion falla-cious, for he has found by experiment that water containing free sul-phuric acid dissolves more lead than water which is either altogethertree from acid or which has been neutralised.The experiments weremade by adding definite quantities of decinormal sulphuric acid to250 C.C. of water, and then immersing in the liquid equal sized piecesof sheet lead, scraped clean immediately before use. The resultsvary. Some water after standing in lead pipes all night contained0.61 grain of lead per gallon. Water taken from the main, havingmarked acid reaction to Poirier’s orange, left in contact with clean lead,dissolved 0.42 t o 0.56 grain per gallon, but when previously renderedfaintly alkaline with lime-water, only 0.14 of lead mas dissolved. Theauthor is of opinion that the free acid in drinking-water is more likelyto be hydrochloric than sulphuric acid.Antiseptic Action of Salicylic Acid. By E.ROBINET andH. PELLET (Bied. Centr., 1882, 63?).-Salicylic acid added to must inbeing 0.24. E. w. P.Action of Water on Lead.D. A. LTECHNICAL CHEJIISTRY. 129quantities of 0.3 gram per litre preserves it perfectly from fermenta-tion, and when yeast has been added to the must, 0.5 gram per litre issufficient to destroy its action.Certain Properties of Hydrogen Cyanide. By C. BRAME( Compt. rend., 94, 1656).-Aqueous solution of hydrocyanic acidcopiously precipitates albumin from its aqueous solutions. Bodiesof animals poisoned by hydrocyanic acid have been preserved for ayear. When the bodies of animals injected with hydrocpnic acidhave been preserved in closed receptacles for several months, they loseall odour of the acid, and acquire that of ammonium formate, whichsalt may be found in the serous liquids.In embalming by means ofhydrocyanic acid, it is necessary to introduce into the body, after theBoiler Explosions. (Dingl. polyt. J., 245, 517.)-It is menbionedthat a silent boiling of liquids is due to the formation of gases. Ifinstead of feeding a boiler with fresh water, boiled or condensedwater be used, which contains less absorbed air, explosive boiling mayoccur after heating the boiler for some time, and as in this case a,large amount of steam is formed in a short time, the plates of theboiler are endangered, owing to the sudden increase in the pressureof steam.D. B.E. W. P.acid, a small quantity of zinc chloride. Ru R.Recovery af Sulphur by Mond's Process. By SUHAEPPL (Dingl.p o l j t . J., 246, 341--345, and 387--392).-The following i s a sum-mary of the author's results and conclusions :-The longer the timethe liquors and oxidised residue are allowed to remain in contact, themore sulphide is dissolved. It is best to oxidise in as concentrated asolution as possible, and to lixiviate for two or three hours. Theweaker the liquor, the more sulphides does it contain ; the stronger it isthe larger is the quantity of thiosulphates : hence the longer t;he liquoris oxidised the greater is the importance of working with weaker solu-tions. In the commencement, a solution was used of 16" T. ; subse-quently this was reduced to 12", so that it was possible to oxidisewith twice the quantity of air without over-oxidising the liquor,whereby a considerable increase in the yield of sulphur was obtained.A further modification was the use of hot water, which not only dis-solves a larger proportion of sulphides in a shorter time, but preventsthe cooling of the residue.Formerly this residue required four to sixhours' heating to render it effective, whilst a t the present time it canbe used a t once for a further oxidation. By mixing the liquor andacid in closed vessels before bringing them into the decomposer, theloss of sulphuretted hydrogen due to defective decomposition is re-duced, whilst, owing to the possibility of working with smaller vessels,the operation is considerably facilitated.It is necessary, however, tolieat the liquor to 80- go", otherwise the sulphur is deposited in a formdifficult to filter. D. B.The Currents of the Gases in Sulphuric Acid Chambers.By K. ABRAHAM (Dingl. po7yt. J., 245, 416--421).-The success ofVOL. XLlV. Ir130 ABSTRACTS OF CHEMICAL PAPERS.the manufacture of sulphuric acid depends largely on the uniformityof the admixture of the reacting gases, not only at the point ofentrance but throughout the chamber. Schwarzenberg’s theory isthat these currents move in horizontal strata from the roof to the floorof the chamber. His views are based on observations of the tem-perature and sp. gr. of the gaseous mixture at successive points. Theauthor from his own investigations concludes that Schwarzenberg’stheory is untenable.He states that the gases on entering come intocontact with a gaseous mixture which differs only slightly from themin sp. gr., and therefore undergo a uniform distribution over the firstportion of the chamber considered in vertical section, the productionof sulphuric acid showing a corresponding uniformity. The coolingaction of the sides and roof of the chamber effects a decrease inthe temperahre : hence the gases travel upwards from the centre anddownwards along the side walls of the chamber. The author for-mulates these phenomena in the following manner :-The gases movein vertical strata perpendicular to the exit, each gaseous moleculedescribing a spiral line whose axis is parallel to the length of thechamber.The practical conclusions arrived at are these :-The inletof the gases should be at the middle height of the chamber, and todetermine the point of origin of the screw motion as closely to thefore side of the chamber as possible and prevent the ingress of thegases in too rapid a manner, the tube is enlarged with a conicalopening. Thesteam should not be introduced in jets along the chamber, but shouldbe admitted through several openings in the roof, each tube to supplytwo perpendicular jets, the orifices of the tubes being sufficiently largeto prevent the entrance of the steam in powerful jets.Utilisation of the Nitrogen-compounds from the Manufac-ture of Sulphuric Acid. By G. WACHTEL (DingZ. polyt. J., 245,517).-Although the loss of potassium nitrate in the manufacture of sul-phuric acid has been greatly diminished, about 50 per cent.of the totalnitrogen in the potassium nitrate still escapes with the exit gases fromthe Gay-Lussac tower. For recovering these nitrogen compounds,the exit gases are drawn by means of a Korting’s injector throughcast iron or clay retorts filled with iron filings heated to redness. Theoxygen compounds of the nitrogen are thereby converted into ammo-nia, which may be absorbed by means of sulphuric or hydrochloricacid. This process is specially adapted for sulphuric acid works notusing the Gay-Lnssac tower.Preparation from Bauxite of Aluminium Sulphate freefrom Iron. By C. FAHLBERG (BUZZ. SOC. Chim. [2], 38,154-156).-Attempts to prepare aluminium sulphate free from iron from banxitehave hitherto been unsuccessful, for the methods proposed have beenfound to be too costly or too complex.The author, in conjunctionwith Semper, has practically solved the problem by the use of lead per-oxide, which is prepared by first triturating a mixture of 2 parts leadmonoxide and 1 part sodium chloride, until the mass assumes thewhite tint of lead oxychloride ; the product is then boiled with bleach-The outlet tube is arranged in a similar manner.D. B.D. BTECHNICAL CHEMISTRY. 131ing powder until lead peroxide is formed, which is washed and pre-served in the damp tjtate. This paste is added to a neutral or slightlyalkaline solution of bauxite in snlphuric acid ; for every part of ironcontained in the solution 20 parts of the dioxide are required. It isnecessary to work with concentrated solutions and to avoid a rise oftemperature ; the iron must also be as a ferric salt.In order to recoverthe peroxide employed, the solid matter is separated by a filter-press,suspended in water, and then dilute sulphuric or nitric acid added,which leaves the peroxide undissolved, so that it can be employed anumber of times without losing any of its properties.V. H. V.Japanese Soils : a Natural Cement. By 0. KORSCHICLT (Chem.News, 46, 187) .-The soil below Tokio yields to hot hydrochloric acidas much as 80 per cent., and this contains about 30 per cent. Si02 and30 per cent. Al,O, + Fe203, and 1.5 to 3.0 per cent.K20 was found inthe lower layers ; it contains little or no quartz, but 50 to 60 per cent.of zeolites. The tufa soils have a low sp. gr., varying from 2.097-2.291. Pull analyses of many samples taken from different depths aregiven. When mixed with lime paste, they form a satisfactory cement,the temperature rising 7" during the mixing ; the proportions used are1 vol. lime to 6 vols. earth. The analyses show a decrease of nitrogenfrom the surface downwards : in the top layer it amounts to 0.521 percent. E. W. P.On Cement and its Appliaation. (Dingl. poZyt. J., 245, 381-387, 456-464, and 499-506) .-Delbruck mentions that in tender-ing for large cement contracts it no longer suffices to give the priceonly, but that the strength of extension forms an important item.The value of cement is determined, therefore, according to the priceand the guaranteed weight which 1 part cement mixed with 3 partssand bears after 28 days' setting.In comparing cements differing inthe rate of setting (slow, medium, and rapid), it is necessary to con-sider the time. According to G. Dyckerhoff, the packing of cement inbags is 10 per cent. cheaper than in casks. It is also mentioned thatwhen rollers are used in the grinding of cement, the motive powerconsumed is less than in the case of the ordinary cement mills. Thisis confirmed by Heyn, Delbriick, Nagel, and Kaemp, who add, that notonly is a more finely divided product obtained, but the wear and tearof the machinery is considerably reduced.For sifting the groundcement, Nagel and Kaemp recommend the use of shaking sieves, madeof perforated sheets of steel, the holes being 1 mm. in diameter.These are said to be stronger than wire sieves, but, like the latter, donot produce a cement fine enough to pass through a sieve with5000 meshes per sq. cm., without leaving a residue of about 30 percent. on the sieve. The air sieve constructed by Michaelis is said toovercome this difficulty. The cement is put into a centrifugal machineand whirled, the fine dust produced being collected in a chamber incommunication with the machine. The process, however, is notpracticable, owing to the excessive consumption of motive power andthe enormous wear and tear of the machine. According to Heintzel132 ABSTRACTS OF CHEMICAL PAPERS.cement made u p with 339 per cent.water hardens in 94 hours ; with30 per cent. in 7$ hours ; with 26+ per cent. in 4 hours ; with 233 percent. in 37 minutes ; and with 20 per cent. in 4 minutes. I n com-paring the time which cement requires for setting, it is usual to mix itwith water to the consistency of a thick paste. It is difficult, how-ever, to fix the quantity of water necessary to effect, this result, assome kinds of cement absorb more water than others. It is best,therefore, to use an excess of water in all cases. Herzog has foundthat in preparing a large block of cement, the temperature increasesconsiderably, especially after the mass has been beaten down. Inbuying cement, it is often stipulated that during the hardening thetemperature should not rise more than 3" to 5", although the quantityof cement to be used to determine this point is not mentioned, eo thatby using larger quantities greater differences are obtained, the resultbeing the rejection of good samples of cement.I n order to economiseheat, Tomei, in burning cement, uses a battery of shaft furnaces con-nected with one another, and worked continuously. Dyckerhoff hasmade a series of useful experiments as to the profitable application ofPortland cement to the preparation of mortar and concrete. He showsthat concrete, when beaten down in the air, requires twice as muchflint as sand, and that it is not economical to throw concrete directinto water. For concreting under water, not more than equal parts ofsand and flint should be used, otherwise the firmness of the concretewill not be the same as that of the mortar used in its preparation.The firmness of mortar and concrete, when beaten down or broughtinto water depends a n the quantity of sand used and the quality ofthe cement, Mortars were examined as to their impermeability towatei- and resistance to atmospheric influences.The followingmixtures were found to give good results :-1 part cement with 1 partfine sand, or 2 parts ordinary sand and 0.5 part lime, or 3 parts sandand 1 part lime, or 6 parts sand and 2 parts lime. D. B.Iron Industry. (Biwgl. polyt. J., 245, 392--394.)-h 1877 thePrussian Chamber of Commerce made a series of %tests with a viewof comparing Rhenish-Westphalian foundry pig with English andScotch brands. It was shown that the prevailing prejudices againstGerman cast iron were no longer tenable, so that since that time theimports of foreign foundry pig into Germany have decreased 'by about12 per cent., whilst the home production has been doubled.Analysis of flue-dust from a, Whitwell apparatus :-K20. Na20.CaO. MgO. Fe20,. ZnO. M U ~ .17-05 9.53 25.95 2.31 0.91 1.30 0.37COz, H,O, CN, and residue. s. SiO,. &03. L-----J1-71 24-05 10.09 6.73The silica is partly free, partly combined ; the sulphur is present aspotassium and calcium sulphides, also as alkaline thiosulphate. Thepotash and soda are in combination with silicic acid, thiosulphuricacid, thiocyanstes, cyanides, and ferrocyanidesTECHNICAL CHEMISTRY* 133The following table gives the chemical analysis of the various ironsexamined in the comparison mentioned above :-Kame of pig iron.Coltness No.1 .. . . ,. . . ..Langloan No. 1 , . . . . . . , . .Clarence No. 3 , . . . . . . . . .Clarence No. 3 , . . . . . . . . .No. 1. Foundry A . . .NO. 3. Foundry c . . .2 No. 1. Foundry D . . .2 No. 1. Foundry D . . .F4 (No. 3. Foundry D . . .NO. 3 from Lorraine.. . . ,.No. 2 from Luxemburg . . .-$.4 4 .4 m -3 -502 -932 -523 *082 -451 '872 -451 9 52 -111 *611.302.013 *502 -701 '86 --dk 2@80,9840 -7521 '4901 '8000 '9770 -9350 9880 '8120.8500.7900 -9300.8500.9661 -8302 -210 -$4 .dau30 *0220.0410 *0550 -0250 -0110 -0080 -0350 *0340 *0210 .c440 *0050 *0180 *010D -041)D -058 --0'2 4 2a$--3 '303.403 '393 '333 '282 -933 '403 *123 *162 *973 -223 '383-27-i-84g 2 -pu--0 *200 -460.130 *120 -260 -500 *190 *150 *490.610 -230 '420 '153 *08,0*1L2 -88 1 0 '55IF:!a4U E?0 -0990 *0710 -0380 -0450 -0600 -0550.0390 -0390 -0400 *0550 *055traces0 *0390'0600 *820 --93 bD 81 -581 *620 -680 -820 *180 -161 q4.81 -920 -970 *860 -720 *990 "790 -630 *099 --dH90 -2490 -5191 -4089.8292 -4093 -4591 '1091 -8092 '0092.7893 '3291 *5092 '1091 -2091 -50 -The following is an analysis of the slags from samples Nos.1 to 3compared with slag obtained from fibrous puddled iron :-No. 1. No. 2. Puddledf--- r--A-, No. 3. iron.SiO, . . 27.50 28.30 31.37 53.30 31.20 32.20A1,0, . . 9-75 11.61 13.09 13.09 10.81 8-17CaO.. . . 58.90 54-94 58-04 52.04 53.17 48.92MgO .. 1.37 0.98 1.16 1-16 1.08 4.79The ratio of the oxygen of the silicic acid to that of the bases inslag No. 1, is as 2 : 3 ; in No. 2, 3 : 4 ; in No. 3, 4 : 5, and in puddlediron, 8 : 9. D. B.Utilisation for Agricultural Purposes of the Basic Slagobtained in the Dephosphorising Process. (Diiagl. polylt. J., 245,513.)-At a large steel works 'in Westphalia some investigations weremade as to the possibility of using the slag from the dephosphorisingprocess for agricultural purposes in the place of phosphaf,e.Thecinder gave on analysis :-Al,Oij andBand, alkalis,SiO,. COz. 8. Pz05. Fe. Mn. CaO. magnesia, &c.6.20 1-72 0.56 19.33 9.74 9.50 47.60 2.68It was found that 10.94 per cent. phosphoric acid, corresponding to56.6 per cent. of the total phosphoric acid, was soluble in ammoniu134 ABSTRACTS OF CHEMICAL PAPERS.citrate, and therefore mesent in a form which will allow it t o beassimilated readily by &ants (compare Abstr., 1882, p. 1229).D. B.Desilvering of Lead. By HAMPE (Dingl. polyt. J., 245, 515).-The author mentions that while the refining of copper by means ofelectricity is being worked with success on a large scale, Keith’s pro-cess of desilverising lead by electrolysis has not made much progress.This is mainly due to the fact that the refined lead does not answerthe requirements of commercially pure lead, and that lead precipitatedelectrolytically from acid solutions does not give a compact substance,but forms lamellar masees, diffused over the whole of the solution.To obtain crystals of lead sufficientlylarge to fall to the bottom of thesolution, it is necessary to increase the distance between the elec-trodes ; however by doing this the resistance, and with it the consump-tion of electricity required to surmount it, are proportionatelyincreased.D. B.Reactions of the Mexican Amalgamation Process. By A. K.HUNTINGTON (Chem. News, 46, 177).-Mercury worked up with silversulphide and sodium chloride extracted seven-eighths of the silverchloride, which was three times as much as that extracted whensodium chloride was absent: ferric oxide causes loss when sodiumchloride is present, as calomel and ferric chloride are formed ; verylittle iron causes much loss.When cupric sulphate is present in themixture, loss of mercury is greater, and the yield of silver less. Theaction of cuprous and cupric chlorides on silver sulphides occurs intwo stages :-Ag2S + CuClz = 2AgC1 + CUS cus + ‘CUC12 = CU2ClZ + s,which results in the formation of silver chloride and free sulphur.The amount of free sulphur and cuprous chloride formed depends onthe strength and qaantity of a solvent for cuprous chloride present,such as sodium chloride or CnC12, the temperature and the pressure.The action of the air in facilitating the action is due to the conversionof cuprous chloride into insoluble oxychloride :3C~zC12 + 3H20 + 30 = ~ C U O , C U C ~ ~ , ~ H ~ O + 2CuCIZ.Cuprous chloride and free sulphur are formed when cupric chlorideand silver sulphide are heated in a closed vessel to a high temperature,an6 if heated long enough, the sulphur is oxidised to sulphuric acid ;if, however, all air be excluded, no sulphur is formed, but cupricRulphate and cuprous chloride instead.Cuprous chloride and silversulphide yield silver chloride and cuprous sulphide. This is contraryto the statements of Malaguti and Durocher, who obtained metallicsilver, but it was because they employed ammonium as a solvent, andnot sodium chloride.Extraction of the Precious Metals from all Kinds of Ores byElectrolysis.By BLAS and MIEST (Chem. News, 46, 121-122).-The authors have discovered that if, in electrolysis, compressed sulphur-E. W. PTECHNICAL CHEMISTRY. 135ores are used as anode in a bath of an electrolyte containing the samemetal as the metal of the ore, on the passage of the current the ore isdecomposed, the sulphur, &c., being precipitated at the anode, whilstthe metal collects at the cathode. Thus with pure galena in a leadnitrate bath, the separation is complete and easy. If the ore containssilica as well, then the silica is deposited along with the sulphur, andremains uncombined ; antimony and arsenic, if present, behave in asimilar manner, being precipitated as insoluble oxides ; they are veryeasily separated by subsequent electrolysis.When large quantities ofarsenic are present, a part of it combines with the sulphur, and formsrealgar or orpiment. When ores containing several metals areoperated on, the precious metals, being most easily precipitated, arethrown down first in the metallic: state at the cathode under the actionof a moderate current. The final separation of these metals requiresvery little battery power, for the mass of metal when dissolved underthe action of the current regenerates sufficient heat for the ulteriorseparation of each metal separately. The products a t the anode areextracted and purified by treatment with carbon bisulphide, and after-wards by separate electrolysis.The decanted carbon bisulphidesolution of sulphur is distilled, the latter being left pure. If the oreis a polysulphide, and is mixed with much iron, sulphur and ironoxide are obtained in the first operation. These are best separated byelectrolysing in a dilute sulphuric acid-bath ; pure sulphur is obtainedat the anode and basic iron sulphate at the cathode. By this process, 18 horse-power is required to produce 1 kilo. of copper from a sul-phurous ore in one hour. As an example of the working with a com-plex ore, they describe the treatment of an argentiferous lead orecontaining iron, copper, and zinc. The curreut being sufficientlystrong, the iron and zinc will dissolve as readily as the other metals,but will not be precipitated so easily, therefore the solution willgradually become saturated with iron and zinc; the current is thenregulated so that only the lead, silver, gold, and copper are precipitatedon the cathode, while the zinc remains dissolved as nitrate.As thebath becomes saturated, the iron yields to the zinc, and is precipitatedto the bottom as ferric oxide, and as soon as the solution is nearlysaturated with zinc nitrate, it is syphoned off; the metals are thenremoved from the cathode, the sulphur and silica from the anode, and theiron oxide from the bottom, of course all separately. The sulphur, &c.,and the metals are treated as above described. The zinc nitratesolution is treated with a small quantity of zinc oxide, which throwsdown the iron ; the lead, copper, and silver retained (if any) are pre-cipitated by passing a current through the solution, using a zinc anode.The pure zinc nitrate may be treated by a stronger electric currentif metallic zinc is required, or chemically if zinc oxide is wanted.Freezing of Wine.By J. MORITZ (Bkd. Centr., 1882, 716).-Wine shows a tendency t o remain liquid below its true solidifyingpoint ; the percentage of alcohol present determines the freezingpoint ; the higher the percentage the lower will be that point, rangingfrom 3.3-5-9" for an alcoholic strength of 7.8-12-5 of alcohol byvolume. E. W. P.D. A. L136 ABSTRACTS OF CHEMICAL PAPERS.Preservation of Beer. By A. H. BAUER (Ried.Centr., 1882, 719).Unless salicylic acid is present in large quantities, it will not preservebeer, but Pasteurising and a small addition of acid preserves beer for3-6 months.Borax is useless as a preservative.(Bied. Ceiitr., 1882, 717.)-To estimate the amountof wort removed in the grains, 50 grams of the grains are shaken upwith 200 C.C. water for 10 minutes, the sp. gr. of the liquid after filter-ing is then taken, and the percentage of extract deduced. To estimatethe starch left in the grains, a sample is weighed and dried andpowdered, and then submitted to the action of dimtase a t 60” ; an ex-tract is then made, and the difference between the sp. gr. of the firstand second extract corresponds to the staroh in the grains.Loss of Sugar by long Steaming of the Mash.” By V. GRIESS-MAYER (Bied. Cenlr., 1862, 717).-l’his loss has been attributed tothe formation of furfural, but the author believes it to be due to thephosphoric acid in the nucle’in, which converts the starch into laevu-linic acid.Maltose is converted by acids under pressure into dextrose,and then furfuaal and formic acid may be produced. In sugar-beet,however, the action of the acid is to produce dextrose and I~evulose,and from the latter lavulinic acid is formed. E. W. P.E. W. P.Beer-grains.E. W. P.Does Potato-sugar contain any Deleterious Matter ? Byv. MERING (Bied. Cer~tr., 1882, 699).-It has been st’ated by Schmitzand Nessler that in the unfermeniable portion of potato-sugar thereis some substance which produces ill effects on animals. By experi-ments the author proves that this unfermentable substance is not dele-terious, but that it is a compound allied to the carbohydrates, and isof some nutritive value. E. W. P.Purification of Sugar-beet Juice. By SCHOTT and others (Ried.Centr., 1882, 697).-According to Schott’s patent, the amount ofpotassium present in the juice must first be estimated, and then jfthere is not a sufficiency of lime present, gypsum is to be added, so asto have 0.593 part CaO for every 1 part K20, then a dilute solutionof ferrous sulphate is poured in, and the whole heated nearly toboiling, finally allowing it to settle, filtering through ‘‘ charred peat,”and evaporating.Siegert in his patent states that after boiling the juice with lime afresh supply of lime is to be added, and after passing it through a,filter-press, the lime is to be removed by carbonic anhydride. Bythis process, treatment wit’h charcoal may be avoided. Licht haspatented a “ barium chloride” method, whereby the organic acids areprecipitated as salts of barium. A similar patent is that of Kottmann,in which strontium chloride is employed. E. W. P