148 ABSTRACTS OF OHFJIICAL PAPERS. I n o r g a n i c Chemistry. Afinities of Iodine in Solution. By H. GAUTIER and G. CHARPY (Compt. rend., 111, 645--647).-1f mercnry is agitated with any solution of iodine, a green precipitate of mercurous iodide is formed, but if the mercury coutains another metal, the iodine combines with the latter in proportions depending on the nature of the solvent. In the case of an amalgam of lead, the difference in colour between lead and mercurous iodides enables the change t o be followed. Brown solutions of iodine (in alcohol, ether, acetone) yield with lead amalgam ft yellow precipitate of lead iodide, even when the pro- portion of lead is aery small, and no mercurous iodide is formed nnt.il .all the lead has been converted into iodide. On the other hand, violet solutions of iodine (in chloroform, carbon bisulphide) give green mercurous iodide, eveti in presence of con- siderable quantities of lead and when the iodine is in excess.Solutions of intermediate tint give precipitates intermediate in colou- between lead iodide and mercurous iodide, and it is found that it’ the solutions of iodine in various solvents are arranged in order according to their colour, and a h according to the colour of the pre- cipitate which they yield when agitated with lead amalgam, the two orders are the same. The colour of the precipitate is indepen- dent of the composition of the amalgam and the concentration of the iodine solution. Careful examination of the reaction shows that brown solutions of iodine and pure mercury at first yield mercuric iodide, which passes into solution, whilst violet solutions of iodine at once form mercurous iodide, even whilst some free iodine remains. I n presence of lead amalgam, brown solutions of iodine first form mercuric iodide, which attacks the lead, forming lead iodide and mercurous iodide, and the latter is again converted into mercuric iodide by the free iodine.No permanent precipitate of mercurous iodide is formed with brown solutions until all the lead has been converted into iodide. It follows from these results that violet solutions of iodine contain the element in a more simple molecular condition, with a tendency to at once form mercurous iodide, this tendency beiug more marked, the simpler the condition of the iodine. The phenomena seem $0 belong t o the same order as those to which Berthelot has given ihe name “ tendency to conservation of type.” By H.BECQUEKEL and H. MOISSAN (Compt. rend., 111, 669--672).--It is well known that certain C. H. B. Fluorapar from Quinci6.INORBANIO OHEMISTRY. 149 specimens of fluorspar, when powdered, emit a peculiar odour, which has been attributed by different observers to free fluorine, hypo- chlorous acid, ozone, hydrocarbons, &c. Thc fluorspar examined by the authors was deep violet in colour, and came from QuinciB, near Villefranche. I t had the composition Ca, 36.14 (= CaF,, 70.47); Fez03 + A1,03, 3-93 ; SO4, 25.00 ; loss at a red heat 2-10 per cent ; sp. gr. 3.117. When powdered, it emitted an odour recalling that of ozone and likewise that of fluorine.Moissan has shown that fluorine decom- poses water with liberation of ozone. The odour from the fluorspar is very similar to that emitted from the electrolytic cell in the isola- tion of flumine, and even if the odour is due to ozone, the latter may be a product of the action of free fluorine on the moisture of the air. Fluorspar from Quincik, when powdered in contact with moist air, evolves a gas which at once acts on ozone paper. If moistened with starch paste and potassium iodide solution, and powdered under a microscope, bubbles of gas are seen to escape, and an intense blue coloration is produced. When the fluorspar is powdered with sodium chloride or potassium bromide or iodide, free chlorine, bromine, or iodine is liberated. When heated above a red heat, the fluorspar decrepitates, loses its colour, and becomes ochreous, and after wards gives no trace of ozone when powdered.If heated at 250" for an hour, which is quite sufficient to destroy all ozone, it still gives, when powdered, a strong reaction with ozone paper. Small fragments of the mineral, when heated in a small glass tube, corrode its surface ; when powdered with silicon, a pungent odour is emitted, and if the mixture is heated, silicon fluoride IS evolved. If small fragments of the mineral are left in contact with water, the water becomes acid, and if the liquid is then evaporated in watch glasses, the latter are corroded. No similar results were obtsined with a white fluorspar from the Pyrenees, and although i t is possible that the fluorine results from the dissociation of a perfluoride, the authors regard it as more probable that the free fluorine is occluded in the mineral.The Molecular Weight and Refractive Energy of Sulphur Dichloride. By T. COSTA (Gazzetta, 20,367-372).--The existence of definite compound of the composition SC1, has been repeatedly called in question (see this Journal, 2870,455 ; 1871,1163 ; Abstr., 1878,553 ; 1886, 977) ; and the substance held by some to be sulphur dichloride has been variously regarded as a solution of chlorine in the mono- chloride, or as rt compound in a state of partial dissociation. The author has determined cryoscopically the molecular weight of the reddish-brown liquid obtained by saturating the monochloride with chlorine below O", and then removing any excess of chlorine by passing in a current of carbonic anhydride, and the results of the determinations, both in benzene and acetic acid solution, agree with the molecnlar formula SCI,. This substance can, therefore, no longel*- be said to exist in a state of partial dissociation.Its density at 15.4" is 1.64819 and its molecalar refractive energy PHa = 1.57169, pNa = 1.57806. S. B. A. A. C. H. B.150 ABSTRACTS OF UHEMICAL PAPERS. Specific Gravity of Sulphuric Acid of Different Degrees of Concentration. By G. LUNGE and M. ISLER (Zeit. ang. Chem,., 1890,129-1 36) .-In consequence of tohe discovery of errors in Kolb'F table, the authors have made fresh determinations with great care. The curve plotted from the results, whilst agreeing in many places closely with that of Kolb, is much smoother, and at the extremes, differs somewhat considerably.The table, of which the following is an abstract, was obtained by graphic interpolation ; iu the original, i t is given for intervals of 0.005 (lo Twaddell) in the specific gravity :- Sp. gr. at 15" in vacuo. 4 O 1,000 1 -020 1 -044) 1 -060 1 -060 1 -100 1.120 1 -144) 1'160 1.180 1.200 1 -220 1 *240 1 -860 1 -280 1 -300 1 *320 1 '34.0 1 -860 1 *380 ~~~ Percentage of H2S0,. 0 *09 3 *03 5 *96 8 -77 11 *60 14 -35 17 -01 19 61 22.19 24 *76 27 -32 29 '84 32 '28 34.57 36 -87 39.19 41 *50 43 '74 45 *88 48 -00 8p. gr. st 15" in vacuo. e0 -- 1 -400 1 '420 1 *440 1.460 1 -480 1 '500 1 0520 1.540 1-560 1 *580 1 *600 I *620 1 -640 1 * 660 1 -680 1 -700 1 -720 1 *740 1 -760 1.780 Percentage of H2S04.50-11 52 -15 54 -07 55 *97 55' -83 59 -70 61 *59 63 -43 65 *C8 66 -71 68 *51 70 -38 71 *99 73 -64 75 '4.2 77 -17 78 '92 80 -68 82 -44 M -50 Sp. gr. at in vacuo. -- 1 -800 1 *820 1 -824 1 *826 1 *828 1.830 1 -832 1 -834 1 -836 1,838 1 *840 1 -8405 1 *8410 1 -8415 1 *8410 1 % a 5 1 93400 1 -8395 1 * 8390 1 -8385 Percentage of HSSOI. -- 86 '90 90 '05 90 *80 91 -25 91 -70 92 -10 92 -52 93 -05 93 -80 94 *60 95 *60 95 -95 97 -00 97 -70 98 -20 98 *70 99 *20 99.45 99 *70 99 *95 M. J. S. Reduction of Oxygen Compounds with Sodium. By. M. ROSENFELD (Ber., 23, 3147-3149).-Sodiiim may be obtained in a finely-powdered condition by triturat ion with some other solid sub- stance. Such a niixtnre ot' sodium and zinc oxide ignites spon- taneously, and leaves a residue of metallic zinc.Ferric oxide and lead oxide react in a similar manner, whilst gypsum is reduced to calcium sulphide. Certain orgauic compounds, sach as pyrogallol, wheat starch, or salicylic acid, inflame immediately on admixture with sodium, carbon being separated ; other substances, such as milk sugar and cane sugar, after admixture with sodium, require to be ex- posed t o moist air before reaction takes place. In the cme of com- pounds which only contain carboxylic oxygen, the sodium salt of the acid is formed. Sodium benzoate and sodium oxulaie are obtained from benzoic and oxalic acids respectively. The carbonaceous residue from rosaniline, toluidine, albumin, and other amido-compounds contains sodium cyanide ; brucine, morphine, and strychnine yield aIKOROANIC CHEMISTRY.151 porous mass of charcoal free from cyanogen. Both sodium cyanide iLnd sodium cyanate were obtained from uric acid. “ Saccharin ” vields a residae containing sodium thiosulphate and sodium cyanide. J. B. T. By A. FOCK and K. KLUSS (Ber., 23, 3149-3151).-Ammoniu1n pyrosulphite, ( NH,),S205. is prepared by passing sulphurous anhydride into cold, concentrated, aqueous ammonia until the liquid becomes yellow; i t is then allowed to evaporate spontaneously in a vacuum. The salt crystallises in large, thick, deliquescent plates, which belong to the rhombic system. M.arignac has shown that the corresponding potassium salt crystal- lises in the monoclinic system. Ammonium Pyrosulphite. J. B. T. Properties of some Beryllium Salts and of the correspond- ing Aluminium Compounds.By F. SESTINI {Guzzetta, 20, 313-319).-( 1.) Phosphates. The phosphates mere prepared in the gelatinous state by precipitating ber.yllium sulphate and potassium alum respectively with disodium phosphate, and washing the pre- cipitate for 4 to 6 days ; they are both sparingly soluble in distilled water, the beryllium salt being considerably t-he more soluble of the two. On igniting the moist beryllium phosphate, it left 6 per cent. of its weight of white anhydrous phosphate. A litre of a saturated solution of beryllium phosphate in 2 per cent. acetic acid contains 0.550 gram of t h e anhjdrous salt (containing, however, 74.9 per cent. P,& instead of 74.2 per cent.). A similar solution of the aluminium salt, however, contains 0.373 gram of phosphate dissolved, containing 87.1 per cent.P205 (instead of 54.8 per cent.) ; this excess of acid is probably due to the formation of a little beryllium pyrophosphate and to the conversion of f~ portion of tho aluminium phosphate by the acetic acid int.0 a more soluble acid phosphate. A litre of a saturated solution of the beryllium salt in 10 per cent. acetic acid conlains 1.725 grams, and the corresponding niu miniuin solution Q.30 gram of the respective anhydrous Phosphates. On gently heating the acetic acid solution of beryllium phosphate, it becomes turbid, and near the boiling point a white precipitate of a basic phosphate, of the formula 3Be0,P20,,3H20 + Aq, is deposited; a solution of the aluminium salt at most becomes opalescent. (2.) Cai-bonates.-lOO C.C.of water saturated with carbonic an- hydride at the ordinary pressure dissolves 0.185 gram of anhydrous beryllium oxide, and the solution becomes turbid on agitation or on !ioiling. Under the same conditions, only 0.001 gram of aluminium oxide passes into solution. The solubility of the beryllium oxide is due, according to the author, to the formation of an acid carbonate. ;5. B. A. A. Magnesium Lead Chloride. By R. OTTO and D. DREWES ( A w . ~ . Pha~n.t., 228, 495-498) .-A hot concentrated magnesium chloride solution dissolves a considerable amount of lead chloride and deposits, on cooling, a double chloride, PbC12,2MgC12 + 13H20, in small, white, lustrous, indistinct crystais. The salt is exceedingly hypo- scopic ; moisture quickly converts it into a solution of magnesium152 ABSTRACTS OF CHEMIOAL PAPERS.chloride, holding lead chloride in suspension. chlorides appear to give a similar compound. Electrolysis of Fused Aluminium Fluoride. By A. MINET (Uontpt. reud., 111, 603-606). The composition of the bath which gives the best results corresponds with the formula 12NaCl + AI,F,,GNaF ; melting point 675" ; temperature at which vapours are evolved, 1035"; sp. gr. at 820" = 1.76; coefficient of expansion 5 x 10-4; electrical conductivity at 870" = 3.1. The relation o€ the conductivity to the temperature is expressed by the equation Ct = 3*1[1 + 0*0022(t - 870")J. For a current of 1200 amphres, the mass of the bath is 20 kilos., the intensity of the current a t the positive pole is 1 ampere, and the difference of potential between the electrodes is 5.5 volts.The composition of the bath is kept constant bg the gradual addition of a mixture of aluminium hydroxide, &41,02( OH),, 416.4 parts, cryolite, 210.4 parts, and aluminiuni oxy- fluoride, A12F,,3A1,0,, 238.4 parts. The difference of potential, e, between the electrodes when the electromotive force is considerably below that required to produce decomposition is expressed by the equation E = KI, I being the in- tensity of the current, and the temperature being constant. S s t'he point is approached at which the electromotive force of polarisation is equal to the electromotive force of decomposition of the electrolyte, the diEerence of potential cannot be calcutated by means of any simple expression.At 870°, the maximum density of the current a t the electrodes, corresponding with the first, period of electrolysis of the bath specified, varies between 0.02 and 0.03 amp8re. During the second period of electrolysis, when the electromotive force is sufficient to produce decomposit'ion, up to a density of 1 ampere at the positive electrode, the difference of potential is expressed by the equation a = e + p l , where e is the electromotive force of decomposition, and p is the resistance of the electrolyte. At 852', e = 2.15 and p = 0 31 ; at 890", e = 2.40 and p = 0.0044 ; at 980°, e = 0.34 and p = 0.0033. For densities of current higher than 1 ampBre, the difference of potential cannot be calculated as a function of the intensity of the current by any simple expression ; it rapidly attains a value simiiar to that existing in the electric arc.In presence of salts of iron or silicon, within certain limits of density of current at the positive electrode, the salts decompose according to Sprague's law. At 810°, with salta of iron, e = 0.75 and p = 0.0093 ; at 840°, with silicou compounds, e = 1.37 and p = 0.0089 ; at 870°, with aluminium salts, e = 2.15 and p = 0.0085. Prepamtion of Chromium from Potassium Chromium Chloride and Magnesium. By E. GLATZEL (Rer., 23, 3127- S130).-Chromium can be quickly prepared in an almost chemically pure condition in the following mancer :-Potassium dichromate (100 grams) is dissolved in the least possible quantity of water, the solution mixed with hydrochloric acid of sp. gr. 1.124 (400 c.c.), and then 80 per cent.alcohol (100 c.c.) gradually added. The solu- tion of potassium chromium chloride obtained in this way is treated Calcium and lead J. T. C. H. BMINERALOGICAL CHEMISTRY. 153 with potassium chloride (160 grams), the filtered solution evaporated to dryness, the residue heated until anhydrous, freed from the green portions, which are produced by the decomposition of the double salt, then powdered, and mixed with magnesium filings (50 grams). This mixture is heated, for about half an hour, to a bright-red heat, in a closed Hessian crucible in a wind-furnace, care being taken that the potassium chloride does not volatilise completely, otherwise the chrom- ium is partially oxidised. The melt is separated from the super- ficial layer of chromium oxide, treated with water, and the finely divided metal freed from salts and unchanged magnesium by washing it with water, then boiling it with dilute nitric acid, and again wash- ing with water, all the washing being done by decantation.The yield of the metaI, dried at iOO", is about 27 grams. Chromium, prepared in this way, is a light-grey, crystalline, non- magnetic powder of sp. gr. 6.7284 at 16"; it can be melted in a Deville's furnace, but only with great difficulty, and after being melted it shows a silvery fracture. Two analyses of the powder showed that it contained 99.33 to 99.37 per cent. of chromium, and that it was free from silver and magnesium. F. S. K.148 ABSTRACTS OF OHFJIICAL PAPERS.I n o r g a n i c Chemistry.Afinities of Iodine in Solution.By H. GAUTIER and G. CHARPY(Compt. rend., 111, 645--647).-1f mercnry is agitated with anysolution of iodine, a green precipitate of mercurous iodide is formed,but if the mercury coutains another metal, the iodine combines withthe latter in proportions depending on the nature of the solvent.In the case of an amalgam of lead, the difference in colour betweenlead and mercurous iodides enables the change t o be followed.Brown solutions of iodine (in alcohol, ether, acetone) yield withlead amalgam ft yellow precipitate of lead iodide, even when the pro-portion of lead is aery small, and no mercurous iodide is formed nnt.il.all the lead has been converted into iodide.On the other hand, violet solutions of iodine (in chloroform, carbonbisulphide) give green mercurous iodide, eveti in presence of con-siderable quantities of lead and when the iodine is in excess.Solutions of intermediate tint give precipitates intermediate incolou- between lead iodide and mercurous iodide, and it is found thatit’ the solutions of iodine in various solvents are arranged in orderaccording to their colour, and a h according to the colour of the pre-cipitate which they yield when agitated with lead amalgam, thetwo orders are the same.The colour of the precipitate is indepen-dent of the composition of the amalgam and the concentration of theiodine solution.Careful examination of the reaction shows that brown solutions ofiodine and pure mercury at first yield mercuric iodide, which passesinto solution, whilst violet solutions of iodine at once form mercurousiodide, even whilst some free iodine remains.I n presence of leadamalgam, brown solutions of iodine first form mercuric iodide, whichattacks the lead, forming lead iodide and mercurous iodide, and thelatter is again converted into mercuric iodide by the free iodine. Nopermanent precipitate of mercurous iodide is formed with brownsolutions until all the lead has been converted into iodide.It follows from these results that violet solutions of iodine containthe element in a more simple molecular condition, with a tendency toat once form mercurous iodide, this tendency beiug more marked, thesimpler the condition of the iodine. The phenomena seem $0 belongt o the same order as those to which Berthelot has given ihe name“ tendency to conservation of type.”By H.BECQUEKEL and H. MOISSAN(Compt. rend., 111, 669--672).--It is well known that certainC. H. B.Fluorapar from Quinci6INORBANIO OHEMISTRY. 149specimens of fluorspar, when powdered, emit a peculiar odour, whichhas been attributed by different observers to free fluorine, hypo-chlorous acid, ozone, hydrocarbons, &c. Thc fluorspar examined bythe authors was deep violet in colour, and came from QuinciB, nearVillefranche. I t had the composition Ca, 36.14 (= CaF,, 70.47);Fez03 + A1,03, 3-93 ; SO4, 25.00 ; loss at a red heat 2-10 per cent ;sp. gr. 3.117.When powdered, it emitted an odour recalling that of ozone andlikewise that of fluorine. Moissan has shown that fluorine decom-poses water with liberation of ozone.The odour from the fluorsparis very similar to that emitted from the electrolytic cell in the isola-tion of flumine, and even if the odour is due to ozone, the latter maybe a product of the action of free fluorine on the moisture of the air.Fluorspar from Quincik, when powdered in contact with moist air,evolves a gas which at once acts on ozone paper. If moistened withstarch paste and potassium iodide solution, and powdered under amicroscope, bubbles of gas are seen to escape, and an intense bluecoloration is produced. When the fluorspar is powdered with sodiumchloride or potassium bromide or iodide, free chlorine, bromine, oriodine is liberated. When heated above a red heat, the fluorspardecrepitates, loses its colour, and becomes ochreous, and after wardsgives no trace of ozone when powdered.If heated at 250" for anhour, which is quite sufficient to destroy all ozone, it still gives,when powdered, a strong reaction with ozone paper.Small fragments of the mineral, when heated in a small glasstube, corrode its surface ; when powdered with silicon, a pungentodour is emitted, and if the mixture is heated, silicon fluoride ISevolved. If small fragments of the mineral are left in contact withwater, the water becomes acid, and if the liquid is then evaporated inwatch glasses, the latter are corroded.No similar results were obtsined with a white fluorspar from thePyrenees, and although i t is possible that the fluorine results fromthe dissociation of a perfluoride, the authors regard it as moreprobable that the free fluorine is occluded in the mineral.The Molecular Weight and Refractive Energy of SulphurDichloride.By T. COSTA (Gazzetta, 20,367-372).--The existence ofdefinite compound of the composition SC1, has been repeatedly calledin question (see this Journal, 2870,455 ; 1871,1163 ; Abstr., 1878,553 ;1886, 977) ; and the substance held by some to be sulphur dichloridehas been variously regarded as a solution of chlorine in the mono-chloride, or as rt compound in a state of partial dissociation. Theauthor has determined cryoscopically the molecular weight of thereddish-brown liquid obtained by saturating the monochloride withchlorine below O", and then removing any excess of chlorine bypassing in a current of carbonic anhydride, and the results of thedeterminations, both in benzene and acetic acid solution, agree withthe molecnlar formula SCI,.This substance can, therefore, no longel*-be said to exist in a state of partial dissociation. Its density at 15.4"is 1.64819 and its molecalar refractive energy PHa = 1.57169, pNa =1.57806. S. B. A. A.C. H. B150 ABSTRACTS OF UHEMICAL PAPERS.Specific Gravity of Sulphuric Acid of Different Degrees ofConcentration. By G. LUNGE and M. ISLER (Zeit. ang. Chem,.,1890,129-1 36) .-In consequence of tohe discovery of errors in Kolb'Ftable, the authors have made fresh determinations with great care.The curve plotted from the results, whilst agreeing in many placesclosely with that of Kolb, is much smoother, and at the extremes,differs somewhat considerably. The table, of which the following isan abstract, was obtained by graphic interpolation ; iu the original, i tis given for intervals of 0.005 (lo Twaddell) in the specific gravity :-Sp.gr. at15" in vacuo.4 O1,0001 -0201 -044)1 -0601 -0601 -1001.1201 -144)1'1601.1801.2001 -2201 *2401 -8601 -2801 -3001 *3201 '34.01 -8601 *380~~~Percentageof H2S0,.0 *093 *035 *968 -7711 *6014 -3517 -0119 6122.1924 *7627 -3229 '8432 '2834.5736 -8739.1941 *5043 '7445 *8848 -008p. gr. st15" in vacuo. e0--1 -4001 '4201 *4401.4601 -4801 '5001 05201.5401-5601 *5801 *600I *6201 -6401 * 6601 -6801 -7001 -7201 *7401 -7601.780Percentageof H2S04.50-1152 -1554 -0755 *9755' -8359 -7061 *5963 -4365 *C866 -7168 *5170 -3871 *9973 -6475 '4.277 -1778 '9280 -6882 -44M -50Sp. gr.atin vacuo.--1 -8001 *8201 -8241 *8261 *8281.8301 -8321 -8341 -8361,8381 *8401 -84051 *84101 -84151 *84101 % a 51 934001 -83951 * 83901 -8385Percentageof HSSOI.--86 '9090 '0590 *8091 -2591 -7092 -1092 -5293 -0593 -8094 *6095 *6095 -9597 -0097 -7098 -2098 *7099 *2099.4599 *7099 *95M. J. S.Reduction of Oxygen Compounds with Sodium. By. M.ROSENFELD (Ber., 23, 3147-3149).-Sodiiim may be obtained in afinely-powdered condition by triturat ion with some other solid sub-stance.Such a niixtnre ot' sodium and zinc oxide ignites spon-taneously, and leaves a residue of metallic zinc. Ferric oxide andlead oxide react in a similar manner, whilst gypsum is reduced tocalcium sulphide. Certain orgauic compounds, sach as pyrogallol,wheat starch, or salicylic acid, inflame immediately on admixturewith sodium, carbon being separated ; other substances, such as milksugar and cane sugar, after admixture with sodium, require to be ex-posed t o moist air before reaction takes place. In the cme of com-pounds which only contain carboxylic oxygen, the sodium salt of theacid is formed. Sodium benzoate and sodium oxulaie are obtainedfrom benzoic and oxalic acids respectively.The carbonaceous residuefrom rosaniline, toluidine, albumin, and other amido-compoundscontains sodium cyanide ; brucine, morphine, and strychnine yield IKOROANIC CHEMISTRY. 151porous mass of charcoal free from cyanogen. Both sodium cyanideiLnd sodium cyanate were obtained from uric acid. “ Saccharin ”vields a residae containing sodium thiosulphate and sodium cyanide.J. B. T.By A. FOCK and K. KLUSS (Ber., 23,3149-3151).-Ammoniu1n pyrosulphite, ( NH,),S205. is prepared bypassing sulphurous anhydride into cold, concentrated, aqueousammonia until the liquid becomes yellow; i t is then allowed toevaporate spontaneously in a vacuum. The salt crystallises in large,thick, deliquescent plates, which belong to the rhombic system.M.arignac has shown that the corresponding potassium salt crystal-lises in the monoclinic system.Ammonium Pyrosulphite.J.B. T.Properties of some Beryllium Salts and of the correspond-ing Aluminium Compounds. By F. SESTINI {Guzzetta, 20,313-319).-( 1.) Phosphates. The phosphates mere prepared in thegelatinous state by precipitating ber.yllium sulphate and potassiumalum respectively with disodium phosphate, and washing the pre-cipitate for 4 to 6 days ; they are both sparingly soluble in distilledwater, the beryllium salt being considerably t-he more soluble of thetwo. On igniting the moist beryllium phosphate, it left 6 per cent. ofits weight of white anhydrous phosphate. A litre of a saturatedsolution of beryllium phosphate in 2 per cent.acetic acid contains0.550 gram of t h e anhjdrous salt (containing, however, 74.9 per cent.P,& instead of 74.2 per cent.). A similar solution of the aluminiumsalt, however, contains 0.373 gram of phosphate dissolved, containing87.1 per cent. P205 (instead of 54.8 per cent.) ; this excess of acid isprobably due to the formation of a little beryllium pyrophosphate andto the conversion of f~ portion of tho aluminium phosphate by the aceticacid int.0 a more soluble acid phosphate.A litre of a saturated solution of the beryllium salt in 10 per cent.acetic acid conlains 1.725 grams, and the corresponding niu miniuinsolution Q.30 gram of the respective anhydrous Phosphates. On gentlyheating the acetic acid solution of beryllium phosphate, it becomesturbid, and near the boiling point a white precipitate of a basicphosphate, of the formula 3Be0,P20,,3H20 + Aq, is deposited; asolution of the aluminium salt at most becomes opalescent.(2.) Cai-bonates.-lOO C.C. of water saturated with carbonic an-hydride at the ordinary pressure dissolves 0.185 gram of anhydrousberyllium oxide, and the solution becomes turbid on agitation or on!ioiling.Under the same conditions, only 0.001 gram of aluminiumoxide passes into solution. The solubility of the beryllium oxide isdue, according to the author, to the formation of an acid carbonate.;5. B. A. A.Magnesium Lead Chloride. By R. OTTO and D. DREWES ( A w . ~ .Pha~n.t., 228, 495-498) .-A hot concentrated magnesium chloridesolution dissolves a considerable amount of lead chloride and deposits,on cooling, a double chloride, PbC12,2MgC12 + 13H20, in small,white, lustrous, indistinct crystais. The salt is exceedingly hypo-scopic ; moisture quickly converts it into a solution of magnesiu152 ABSTRACTS OF CHEMIOAL PAPERS.chloride, holding lead chloride in suspension.chlorides appear to give a similar compound.Electrolysis of Fused Aluminium Fluoride.By A. MINET(Uontpt. reud., 111, 603-606). The composition of the bath whichgives the best results corresponds with the formula 12NaCl +AI,F,,GNaF ; melting point 675" ; temperature at which vapours areevolved, 1035"; sp. gr. at 820" = 1.76; coefficient of expansion5 x 10-4; electrical conductivity at 870" = 3.1. The relation o€the conductivity to the temperature is expressed by the equationCt = 3*1[1 + 0*0022(t - 870")J. For a current of 1200 amphres,the mass of the bath is 20 kilos., the intensity of the current a t thepositive pole is 1 ampere, and the difference of potential between theelectrodes is 5.5 volts.The composition of the bath is kept constantbg the gradual addition of a mixture of aluminium hydroxide,&41,02( OH),, 416.4 parts, cryolite, 210.4 parts, and aluminiuni oxy-fluoride, A12F,,3A1,0,, 238.4 parts.The difference of potential, e, between the electrodes when theelectromotive force is considerably below that required to producedecomposition is expressed by the equation E = KI, I being the in-tensity of the current, and the temperature being constant.S s t'hepoint is approached at which the electromotive force of polarisation isequal to the electromotive force of decomposition of the electrolyte,the diEerence of potential cannot be calcutated by means of anysimple expression. At 870°, the maximum density of the current a tthe electrodes, corresponding with the first, period of electrolysis of thebath specified, varies between 0.02 and 0.03 amp8re.During the second period of electrolysis, when the electromotiveforce is sufficient to produce decomposit'ion, up to a density of1 ampere at the positive electrode, the difference of potential isexpressed by the equation a = e + p l , where e is the electromotiveforce of decomposition, and p is the resistance of the electrolyte. At852', e = 2.15 and p = 0 31 ; at 890", e = 2.40 and p = 0.0044 ; at980°, e = 0.34 and p = 0.0033.For densities of current higher than1 ampBre, the difference of potential cannot be calculated as a functionof the intensity of the current by any simple expression ; it rapidlyattains a value simiiar to that existing in the electric arc.In presence of salts of iron or silicon, within certain limits ofdensity of current at the positive electrode, the salts decomposeaccording to Sprague's law. At 810°, with salta of iron, e = 0.75and p = 0.0093 ; at 840°, with silicou compounds, e = 1.37 andp = 0.0089 ; at 870°, with aluminium salts, e = 2.15 and p = 0.0085.Prepamtion of Chromium from Potassium ChromiumChloride and Magnesium. By E. GLATZEL (Rer., 23, 3127-S130).-Chromium can be quickly prepared in an almost chemicallypure condition in the following mancer :-Potassium dichromate(100 grams) is dissolved in the least possible quantity of water,the solution mixed with hydrochloric acid of sp. gr. 1.124 (400 c.c.),and then 80 per cent. alcohol (100 c.c.) gradually added. The solu-tion of potassium chromium chloride obtained in this way is treatedCalcium and leadJ. T.C. H. MINERALOGICAL CHEMISTRY. 153with potassium chloride (160 grams), the filtered solution evaporatedto dryness, the residue heated until anhydrous, freed from the greenportions, which are produced by the decomposition of the double salt,then powdered, and mixed with magnesium filings (50 grams). Thismixture is heated, for about half an hour, to a bright-red heat, in aclosed Hessian crucible in a wind-furnace, care being taken that thepotassium chloride does not volatilise completely, otherwise the chrom-ium is partially oxidised. The melt is separated from the super-ficial layer of chromium oxide, treated with water, and the finelydivided metal freed from salts and unchanged magnesium by washingit with water, then boiling it with dilute nitric acid, and again wash-ing with water, all the washing being done by decantation. Theyield of the metaI, dried at iOO", is about 27 grams.Chromium, prepared in this way, is a light-grey, crystalline, non-magnetic powder of sp. gr. 6.7284 at 16"; it can be melted in aDeville's furnace, but only with great difficulty, and after beingmelted it shows a silvery fracture. Two analyses of the powdershowed that it contained 99.33 to 99.37 per cent. of chromium, andthat it was free from silver and magnesium. F. S. K