8 ABSTRACTS O F CHEMICAL PAPERS. Inorganic C h e m i s t r y . Preparation of Chlorine and Hydrochloric Acid by means of Calcium and Magnesium Chlorides. By E. SOLVAY (Cheni. Cedr., 1818, 336) .-The above-mentioned chlorides are mixed with silica and alumina or silicate of alumina, and dried. To obtain chlorine they are intensely heated in a current of sir ; for HC1 they are heated in a current of superheated steam. Silicates and alumi- nates of lime and magnesia are formed as bye-products in this pro- cess, and may be used for making chloride of lime and precipitated silica and alumina, also for making chlorine from hydrochloric acid, and for soda manufacture by the ammonia process. J. X. T. Hydrochloric Acid containing Phosphoric Acid, By E. HOLDERMANN (Arch. Pharm. [3], 13, 100--103).-A sample of hydrochloric acid gave when tested all the reactions for purity, so that when evaporated over a bare flame in a platinum vessel it left a barely perceptible residue, but when iron was dissolved in the acid, a white precipitate was formed, which on examination was found to be due to a large quantity of phosphoric acid present.It is, therefore, advisable, when testing for phosphoric acid by volatilisation, to evaporate the liquid in a watch-glass over the water-bath. E. w. P. Ozone. By JEREYIN (Deut. Chem. Ges. Ber., 11, 988).-The author finds that ozone dissolves to a considerable extent in aqueous oxalic acid, forming n solution which keeps indefinitely. A solution which has been kept some time is a better disinfectant than whenINORGANIC CHEMISTRY.9 fresh. I n the gaseous state ozone keeps better in the light than in the dark. For washing with ozone the author constructs stoppers, stop- cocks, tubes, &., of a composition of powered pumice, paraffin, wax, and resin, which is not acted on by ozone. For experiments with sub- stances which attack paraffin he recommends a composition of gelatine and glycerin. J. R. Oxidation of Nitrous Acid by Ozone and by Moist Oxygen. By BERTHELOT (Aizn. Chim. YJiys. [ 5 ] , 13, 367--368).-1n an acid solution nitrous acid is a t once oxidised to nitric acid by ozone, which niay be exactly determined by this means. A standard solution of a nitrite is acidified and shaken with a gas containing ozone, wliicli oxidises the nitrous acid and is itself Rbsorbed.The excess of nitrite in the solution is then titrated with potassium permnnganate. 111 presence of alkalis, the ozone i s destroyed without acting on the nitrous acid. Dry *oxygen or ozone converts nitrous acid into nitrogen tetroxide, which in presence of water yields nitric acid. It is thus clear that the presence of nitrous acid and ozone simultaneously in t'he air is not possible. Presence of Amrnoniacal Salts in Sea-water. By M. L. DIEULAFAIT (Arm. Chim. Phys. [ 5 ] , 13, 374-409).-The presence of ammoniacal salts in sea-water was first pointed out by Marchand (Mem. Acad. &fed., 19, lb55), and subsequently investigated by Bous- singault (Ayroriomie. Chim. Agrie et Physiol., 208), and Forchammer (Phil. Trms., 155, 203). The author has made fresh determinations of the ammonia present in sea-water ; also of its deposits, employing Boussingault's method with slight modifications.Wrder from the JIeditewanea?z.- This water was taken south of Marseilles, 12 kilometers from the shore, and about the mericlian of Aix. 10 litres were distilled and 4 litres collected and redistilled. 800 C.C. of the second distillate are again distilled, and the ammonia determined in the first 300 C.C. which come over. In this manner the result obtained was *231 mg. NH, per litre. From water taken between hlarseilles and China a t depths varying from 1.5 to 2 metres, the following results were obtained :- mg. N I B per litre. Ismaila.. .......................................... 0-204 Red Sea, long. E. 33" 5 4 , lat. N. 24" 4' ..............0.176 Cape Gardafuy, long. E. 49" 42', lat). N. 12" 44' ........ 0.176 Socatora, north of the island ........................ 0.17C; Bay of Bengal, long. E. 87" 55', lat. N. 5" 34'. ......... 0.136 Coast of Cochin China, long. E. 107" 22', lat. N. 14" 37'.. 0.340 From these results it is seen that ammonia occurs in seas of all latitudes. The quantity of ammonia in the sea-water does not increase pro- portionally to the evaporation of the water, inasmuch as a portion of the ammonia escapes into the air. The Ammonia in the Deposits from Sen-water.-During the evapora - tion of the water in saline marshes, deposits are formed, the first con- sisting of pure cryatallised gypsum covering the surface of the pan, Moist air also slowly oxidises nitrous acid. L.T. 0's.10 ABSTRACTS OF CHEMICAL PAPERS. whilst the second is a black mud, obtained partly by the decomposition of the “ feutre,” the term applied to the “ stratum” of algae which covers the bottom of the salt-pans. There is also a greenish-yellow liquid obtained, which contains some of the refuse of the mud and a large quantity of gxpsum. Each of these contained ammonia in the following proportions :- Gypsum ........ 1.6 mg. NH, per kilo. Liquid.. ........ 3.4 ,, per litre. The water of the pool of Lavaldue contains 250 times more ammonia than the water of the Seine a t Paris, and 50 times more than that of the Bievre, on the banks of which many manufactories stand. By the evaporation of the sea-water, deposits are obtained; in the first place calcium carbonate, mixed with oxide of iron and strontium car- bonate, separates out, but the more important deposits are those of gypsum, which are two-( 1) pure gypsum, and (2 j gypsum mixed with calcium carbonate and some mud, imparting to it a grey colour.There is also a deposit of mud. These last three absorb ammonia, which fhe author has determined in twenty samples obtained from different places to the south of France. The results, of which the following are examples, show the variation in the quantity of ammonia :- Black mud ...... 8.3 ,, 7 9 Pure gypsum. Grey gypsum. Triassic. “g. mg. Simiane (Bouches du Rhone) . . 1.2 6.2 Saint Julien . . . . . . . . . . . . . . . 1.6 2.6 Castellane .................. 2.4 3% La Palud .................. 0.8 3.1 Taulanne.. ..................1.4 3.0 Solli&s (Ville) .............. 1.9 3.1 Le Beausset ................ 3.2 4.3 Le Faron (Toulon) .......... 1.8 4.8 Bandol ...................... 2.2 4.6 Black mud. mg. 15.0 12.2 14.0 11.2 12.7 14.0 11.1 12.9 14-5 The author has also examined some gypsum beds of the tertiary formation for ammonia, arid finds that they correspond with the grey gypsum above, having given the following resalts :- Bois d’dsson ............ Saint Jean de Garquier . . 2.14 ,, 7, 4.04 mg. NH, per kilo. Camoins ................ 2.87 ,, ? > The presence of ammoniacal salts in the gypsum accounts for the disengagement of ammonia in the manufacture of plaster of Paris. The boric acid emitted by the lagoons in Tuscany is often accom- panied by ammonia, which may be explained if it is admitted that the boric acid exists in the saline beds of the lagoon, which absorb ammonia, and that the part played by the volcauic agent is purely mechanical, whereas on the contrary, by assuming the boric acid to have a volcanic origin, the presence of ammonia cannot be explained.The water of Lake d’Enghien contains only 0.07 mg. NH, per litre, whilst the sulphur spring fed by the lake contains 5.06 mg. per litre.1NORGlANJ.C CHEMISTRY. 11 This is due to the fact that the water on emerging from the lake has to pass over sediments, from which it dissolves the ammoniacal salts. The author is of opinion that all saline waters obtain their mineral matter from the two salt-bearing formations, the trias and tertiary, which always contain a consid2rable quantity of ammoniacal salts, and the conclusion he draws is that all saline mineral waters ought to contain abnormal quantities of ammoniacal salts, whether they be sulphurous or not, thermal or not.L. T. 0's. Chemical Action of Water and Saline Solutions on Zinc. By A. J. C. SNYDERS (Deut. Chem. Ges. Ber., 11, 936--949).-The author has examined the action of water and of saline liquids on zinc under various conditions. 1. Zinc decomposes saline solutions, whether concentrated or dilute, without access of oxygen, evolving hydrogen and forming zinc oxide. 2. Solubility of zinc oxide in the saline liquids promotes the action. 3. Zinc oxide dissolves in solutions containing 1 per cent. or less of salt. The solubility varies with different salts, being greatest with ammonium salts.Zinc hydrate and carbonate are insoluble in carbo- nates. The solubility of zinc oxide increases with the strength of the solutions and with the temperature. 4. When a saline liquid is saturated with zinc oxide, the decom- posing action still goes on, the oxide then formed remaining undis- solved. 5. In presence of oxygen free from carbon dioxide, the zinc oxide dissolves more readily, on account of the direct oxidation of the metal. 6. In presence of the carbon dioxide of the air, the solvent action is to some extent prevented, owing to the formation of basic car- bonate. 7. The solvent action is strongest with chlorides and potassium sulphate, weaker with alkaline and barium nitrates and magnesium sulphate. 8. Solutions of alkaline carbonates and sodium phosphate do not act on zinc protected from the air.Even in presence of oxygen, solutions containing 1 per cent. of these salts dissolve but little zinc, because the carbonate or phosphate first formed protects the metal from further action. Nevertheless, traces of zinc oxide are dissolved by still weaker solutions. 9. The solrent action is greater at higher temperatures : a t 0" it is very slight. 10. Solutions of ammonium salts take up more zinc oxide than solutions of salts of fixed alkalis. The surface of the metal remains clean, and nothing is deposited from the solution, even in presence of oxygen. 11. Hard waters do not act on zinc, even when rich in chlorides and sulphates. Soft waters dissolve the more zinc the greater the preponderance of chlorides, sulphates, and ni hates over carbonates and phosphates contained in them.His results are summed up as follows : J. R.12 ABSTRACTS OF CHEMICAL PAPERS. A New Earth of the Cerium Group, and on the Analysis of Natural Niobates. By J. L. S i I I ' r H (Con@. reud., 87, 146-148). -The object of this paper is to call attention to the use the author made of concentrated hydrofluoric acid for decomposing niobates ; its action on samarskite and euxenite being as energetic as that of hydro- chloric acid on calcium carbonate. By the actiori of the acid, all the metallic acid forming oxides, together with the oxides of iron and man- ganese, are dissolved, whilst the insoluble portion contains all the earths and the uranium oxide. The presence of tantalates renders the decomposition more difficult.I n a former memoir, the author divided the earths contained in Carolina samarskite into the yttrium and cerium groups, pointing out however that the latter group might not contain cerium oxide, and that thorium could not be detected i n it x i t h certainty. Since this, he has found that the yttrium group con- tains about two-thirds of yttrium and one-third of erbium, whilst cerium is absent from the group bearing its name. He also points out that the earths of this group contain 10 per cent. of thorium, a small quantity of didymium oxide and an earth (about 3 per cent. of the mineral) which the author considers to be new, if i t is not the hypo- thetical terbium of Mosander. De la Fontaine of Chicago has con- firmed the absence of cerium, and looks upon the new earth as terbia.The author thinks, nevertheless, that he has found a new earth, and that if terbia exists among the oxides of samarskite, it is contained in the yttria group. Comparing the atomic weight of the supposed new earth with those of the oxides of cerium, lanthanum, or didymium determined by JIarignac (0 = 16) we have :- New earth.. ................ 109 (Smith). Cerium oxide .............. 110 (Marignac). Lanthanum oxide., .......... 110 ,, Didymium ,, ............ 112 ,, The new earth differs from those of the j t t h gronp in its action with potassic sulphate, from cerium oxide by its solubility in very dilute HN03, from didymium oxide by its colour, from lanthanum oxide by its colour and the ease with which its salts are decomposed by heat.The author has aIso devised a method for the separation of thorium, as follows : the freshly precipitated oxides are placed in a solution of potash or soda, and a current of chlorine is passed through the mixture when all the oxides are dissolved except those of cerium and thorium ; as the samarskite contaius no cerium, the residue consists merely of a white gelatinous precipitate of thorium oxide. J. $1. T. The supposed New Element Mosandrum. By J. L. SMiTH (Conipt. r e d . , 87, 148--131).-This paper is occupied by a claim for the priority of the discovery of the earth indicated as X by Soret in his paper to the Academy. The author maintains to have found this earth in samarskite from North Carolina, and gives a minute account cf its discovery and of his correspondence with De la FontaineIX'ORGAK'IC CHEMISTRY.13 and Marignac on the subject. Basing his remarks on his own work and tdie spectroscopic examination by Soret, he now has no hesitation i n claiming mosandruin as a new element. On the Discovery of a New Earth announced by J. L. Smith. By C. MARIGSX (Co?72pt. reid., 87, 281-5283 ).-In this paper Marignac points out the reasons leading him to the conclu- sion that Smith's " mosandrum " is identical with Mosander's " ter- bium ; " whilst the earth provisionally designated X by Soret and the author, differs from t,htl former in its absorption phenomena, althougli it shows nirt11~- points of resemblance with an earth described by De la Fontaine of Chicago. J. AT. T. J. M. T.Magnetic Compound; having the Formula RO.Fe,O,. By K. Llsr (Delcf. Clmn. Ges. Be,.., 11, 1512-1.516j.-Lime water pro- duces in a neutral solution of ferric chloride a brown precipitate, which is magnetic, and after ignition has the composition Cs0.Fe207. I n a similar manner magnetic compounds of magnesia and bnryta with ferric oxide can be obtained. The corresponding manganese, nickel, copper, and lead compouuds are formed when soda is added to a solution containing ferric chloride and copper sulphatc, &c., in their equivalent proportions. Magretic compounds are also formed when sodium or potassium carbonate is fused with ferric oxide. w. c. w. Dissociation of Metallic Sulphides. By P. DE CLERMOST and J. PROMJI EL (Co??2pt. re72d., 87, 330, 332 j .-The decomposi- tion which ensnes on boiling certain sulpliides with water is regarded by the authors as due to the dissociation of a previously formed hydrate of the sulphide.They point out that freshly precipitated sulphide of arsenic boiled with water gives rise to a more rapid evolu- tion of sulphuretted hydrogen than tlie same sulphide does when it has previously been dried at 12.5". But if this last is kept in coutact for some hours with hot water in a closed vessel, i t gives off sulphuretted hydrogen, when boiled in an opcn vessel, as rapidly a s the freshly precipitated sulphide. On boiling snlpliides with water in a vacuum, dissociation was observed to occur a t tlie following temperatures : sulphide of arsenic, 22' ; sulphide of iron, 56" ; sulphide of antimony, 95".The dissociation of arsenic sulpliide presented ccrtain pecn- liarities, which the authors believe to be due to the interference of the arsenious acid, which is one of the products of decomposition. The presence of this substance impedes the dissociation, by the formation, as they suppose, of an oxpsulphide which undergoes dissociation more Sulphide of arsenic, to which crystallised arsenious acid has been added, is dissociated more quickly than that to which arsenious acid obtained by the dissociation of tlie sulpliide has been added. As arsenic pentasulphide on dissociation yields arsenious acid and not arsenic acid, the author doubts its existence as a definite chemical compound. R. R. slowly.8 ABSTRACTS O F CHEMICAL PAPERS.Inorganic C h e m i s t r y .Preparation of Chlorine and Hydrochloric Acid by means ofCalcium and Magnesium Chlorides.By E. SOLVAY (Cheni.Cedr., 1818, 336) .-The above-mentioned chlorides are mixed withsilica and alumina or silicate of alumina, and dried. To obtainchlorine they are intensely heated in a current of sir ; for HC1 theyare heated in a current of superheated steam. Silicates and alumi-nates of lime and magnesia are formed as bye-products in this pro-cess, and may be used for making chloride of lime and precipitatedsilica and alumina, also for making chlorine from hydrochloric acid,and for soda manufacture by the ammonia process. J. X. T.Hydrochloric Acid containing Phosphoric Acid, By E.HOLDERMANN (Arch. Pharm. [3], 13, 100--103).-A sample ofhydrochloric acid gave when tested all the reactions for purity, sothat when evaporated over a bare flame in a platinum vessel it lefta barely perceptible residue, but when iron was dissolved in theacid, a white precipitate was formed, which on examination was foundto be due to a large quantity of phosphoric acid present.It is,therefore, advisable, when testing for phosphoric acid by volatilisation,to evaporate the liquid in a watch-glass over the water-bath.E. w. P.Ozone. By JEREYIN (Deut. Chem. Ges. Ber., 11, 988).-Theauthor finds that ozone dissolves to a considerable extent in aqueousoxalic acid, forming n solution which keeps indefinitely. A solutionwhich has been kept some time is a better disinfectant than wheINORGANIC CHEMISTRY. 9fresh.I n the gaseous state ozone keeps better in the light than in thedark. For washing with ozone the author constructs stoppers, stop-cocks, tubes, &., of a composition of powered pumice, paraffin, wax,and resin, which is not acted on by ozone. For experiments with sub-stances which attack paraffin he recommends a composition of gelatineand glycerin. J. R.Oxidation of Nitrous Acid by Ozone and by Moist Oxygen.By BERTHELOT (Aizn. Chim. YJiys. [ 5 ] , 13, 367--368).-1n an acidsolution nitrous acid is a t once oxidised to nitric acid by ozone, whichniay be exactly determined by this means. A standard solution of anitrite is acidified and shaken with a gas containing ozone, wliiclioxidises the nitrous acid and is itself Rbsorbed. The excess of nitritein the solution is then titrated with potassium permnnganate.111presence of alkalis, the ozone i s destroyed without acting on the nitrousacid. Dry *oxygen orozone converts nitrous acid into nitrogen tetroxide, which in presenceof water yields nitric acid. It is thus clear that the presence of nitrousacid and ozone simultaneously in t'he air is not possible.Presence of Amrnoniacal Salts in Sea-water. By M. L.DIEULAFAIT (Arm. Chim. Phys. [ 5 ] , 13, 374-409).-The presenceof ammoniacal salts in sea-water was first pointed out by Marchand(Mem. Acad. &fed., 19, lb55), and subsequently investigated by Bous-singault (Ayroriomie. Chim. Agrie et Physiol., 208), and Forchammer(Phil. Trms., 155, 203). The author has made fresh determinations ofthe ammonia present in sea-water ; also of its deposits, employingBoussingault's method with slight modifications.Wrder from the JIeditewanea?z.- This water was taken south ofMarseilles, 12 kilometers from the shore, and about the mericlian ofAix.10 litres were distilled and 4 litres collected and redistilled.800 C.C. of the second distillate are again distilled, and the ammoniadetermined in the first 300 C.C. which come over. In this manner theresult obtained was *231 mg. NH, per litre.From water taken between hlarseilles and China a t depths varyingfrom 1.5 to 2 metres, the following results were obtained :-mg. N I B per litre.Ismaila.. .......................................... 0-204Red Sea, long. E. 33" 5 4 , lat. N. 24" 4' .............. 0.176Cape Gardafuy, long.E. 49" 42', lat). N. 12" 44' ........ 0.176Socatora, north of the island ........................ 0.17C;Bay of Bengal, long. E. 87" 55', lat. N. 5" 34'. ......... 0.136Coast of Cochin China, long. E. 107" 22', lat. N. 14" 37'.. 0.340From these results it is seen that ammonia occurs in seas of alllatitudes.The quantity of ammonia in the sea-water does not increase pro-portionally to the evaporation of the water, inasmuch as a portion ofthe ammonia escapes into the air.The Ammonia in the Deposits from Sen-water.-During the evapora -tion of the water in saline marshes, deposits are formed, the first con-sisting of pure cryatallised gypsum covering the surface of the pan,Moist air also slowly oxidises nitrous acid.L. T.0's10 ABSTRACTS OF CHEMICAL PAPERS.whilst the second is a black mud, obtained partly by the decompositionof the “ feutre,” the term applied to the “ stratum” of algae whichcovers the bottom of the salt-pans. There is also a greenish-yellowliquid obtained, which contains some of the refuse of the mud and alarge quantity of gxpsum.Each of these contained ammonia in the following proportions :-Gypsum ........ 1.6 mg. NH, per kilo.Liquid.. ........ 3.4 ,, per litre.The water of the pool of Lavaldue contains 250 times more ammoniathan the water of the Seine a t Paris, and 50 times more than that ofthe Bievre, on the banks of which many manufactories stand.By the evaporation of the sea-water, deposits are obtained; in the firstplace calcium carbonate, mixed with oxide of iron and strontium car-bonate, separates out, but the more important deposits are those ofgypsum, which are two-( 1) pure gypsum, and (2 j gypsum mixed withcalcium carbonate and some mud, imparting to it a grey colour.Thereis also a deposit of mud. These last three absorb ammonia, which fheauthor has determined in twenty samples obtained from different placesto the south of France. The results, of which the following areexamples, show the variation in the quantity of ammonia :-Black mud ...... 8.3 ,, 7 9Pure gypsum. Grey gypsum.Triassic. “g. mg.Simiane (Bouches du Rhone) . . 1.2 6.2Saint Julien . . . . . . . . . . . . . . . 1.6 2.6Castellane .................. 2.4 3%La Palud ..................0.8 3.1Taulanne.. .................. 1.4 3.0Solli&s (Ville) .............. 1.9 3.1Le Beausset ................ 3.2 4.3Le Faron (Toulon) .......... 1.8 4.8Bandol ...................... 2.2 4.6Black mud.mg.15.012.214.011.212.714.011.112.914-5The author has also examined some gypsum beds of the tertiaryformation for ammonia, arid finds that they correspond with the greygypsum above, having given the following resalts :-Bois d’dsson ............Saint Jean de Garquier . . 2.14 ,, 7,4.04 mg. NH, per kilo.Camoins ................ 2.87 ,, ? >The presence of ammoniacal salts in the gypsum accounts for thedisengagement of ammonia in the manufacture of plaster of Paris.The boric acid emitted by the lagoons in Tuscany is often accom-panied by ammonia, which may be explained if it is admitted thatthe boric acid exists in the saline beds of the lagoon, which absorbammonia, and that the part played by the volcauic agent is purelymechanical, whereas on the contrary, by assuming the boric acid tohave a volcanic origin, the presence of ammonia cannot be explained.The water of Lake d’Enghien contains only 0.07 mg.NH, per litre,whilst the sulphur spring fed by the lake contains 5.06 mg. per litre1NORGlANJ.C CHEMISTRY. 11This is due to the fact that the water on emerging from the lake hasto pass over sediments, from which it dissolves the ammoniacal salts.The author is of opinion that all saline waters obtain theirmineral matter from the two salt-bearing formations, the trias andtertiary, which always contain a consid2rable quantity of ammoniacalsalts, and the conclusion he draws is that all saline mineral watersought to contain abnormal quantities of ammoniacal salts, whetherthey be sulphurous or not, thermal or not.L. T. 0's.Chemical Action of Water and Saline Solutions on Zinc.By A. J. C. SNYDERS (Deut. Chem. Ges. Ber., 11, 936--949).-Theauthor has examined the action of water and of saline liquids on zincunder various conditions.1. Zinc decomposes saline solutions, whether concentrated ordilute, without access of oxygen, evolving hydrogen and forming zincoxide.2. Solubility of zinc oxide in the saline liquids promotes theaction.3. Zinc oxide dissolves in solutions containing 1 per cent.or less ofsalt. The solubility varies with different salts, being greatest withammonium salts. Zinc hydrate and carbonate are insoluble in carbo-nates. The solubility of zinc oxide increases with the strength of thesolutions and with the temperature.4. When a saline liquid is saturated with zinc oxide, the decom-posing action still goes on, the oxide then formed remaining undis-solved.5. In presence of oxygen free from carbon dioxide, the zinc oxidedissolves more readily, on account of the direct oxidation of themetal.6. In presence of the carbon dioxide of the air, the solvent actionis to some extent prevented, owing to the formation of basic car-bonate.7. The solvent action is strongest with chlorides and potassiumsulphate, weaker with alkaline and barium nitrates and magnesiumsulphate.8. Solutions of alkaline carbonates and sodium phosphate do not acton zinc protected from the air.Even in presence of oxygen, solutionscontaining 1 per cent. of these salts dissolve but little zinc, becausethe carbonate or phosphate first formed protects the metal fromfurther action. Nevertheless, traces of zinc oxide are dissolved by stillweaker solutions.9. The solrent action is greater at higher temperatures : a t 0" it isvery slight.10. Solutions of ammonium salts take up more zinc oxide thansolutions of salts of fixed alkalis. The surface of the metal remainsclean, and nothing is deposited from the solution, even in presence ofoxygen.11. Hard waters do not act on zinc, even when rich in chloridesand sulphates.Soft waters dissolve the more zinc the greater thepreponderance of chlorides, sulphates, and ni hates over carbonatesand phosphates contained in them.His results are summed up as follows :J. R12 ABSTRACTS OF CHEMICAL PAPERS.A New Earth of the Cerium Group, and on the Analysis ofNatural Niobates. By J. L. S i I I ' r H (Con@. reud., 87, 146-148).-The object of this paper is to call attention to the use the authormade of concentrated hydrofluoric acid for decomposing niobates ; itsaction on samarskite and euxenite being as energetic as that of hydro-chloric acid on calcium carbonate. By the actiori of the acid, all themetallic acid forming oxides, together with the oxides of iron and man-ganese, are dissolved, whilst the insoluble portion contains all the earthsand the uranium oxide.The presence of tantalates renders thedecomposition more difficult. I n a former memoir, the author dividedthe earths contained in Carolina samarskite into the yttrium andcerium groups, pointing out however that the latter group might notcontain cerium oxide, and that thorium could not be detected i n itx i t h certainty. Since this, he has found that the yttrium group con-tains about two-thirds of yttrium and one-third of erbium, whilstcerium is absent from the group bearing its name. He also points outthat the earths of this group contain 10 per cent. of thorium, a smallquantity of didymium oxide and an earth (about 3 per cent. of themineral) which the author considers to be new, if i t is not the hypo-thetical terbium of Mosander.De la Fontaine of Chicago has con-firmed the absence of cerium, and looks upon the new earth as terbia.The author thinks, nevertheless, that he has found a new earth, andthat if terbia exists among the oxides of samarskite, it is containedin the yttria group.Comparing the atomic weight of the supposed new earth with thoseof the oxides of cerium, lanthanum, or didymium determined byJIarignac (0 = 16) we have :-New earth.. ................ 109 (Smith).Cerium oxide .............. 110 (Marignac).Lanthanum oxide., .......... 110 ,,Didymium ,, ............ 112 ,,The new earth differs from those of the j t t h gronp in its actionwith potassic sulphate, from cerium oxide by its solubility in verydilute HN03, from didymium oxide by its colour, from lanthanumoxide by its colour and the ease with which its salts are decomposed byheat.The author has aIso devised a method for the separation of thorium,as follows : the freshly precipitated oxides are placed in a solution ofpotash or soda, and a current of chlorine is passed through the mixturewhen all the oxides are dissolved except those of cerium and thorium ;as the samarskite contaius no cerium, the residue consists merely ofa white gelatinous precipitate of thorium oxide.J. $1. T.The supposed New Element Mosandrum. By J. L. SMiTH(Conipt. r e d . , 87, 148--131).-This paper is occupied by a claimfor the priority of the discovery of the earth indicated as X by Soretin his paper to the Academy.The author maintains to have foundthis earth in samarskite from North Carolina, and gives a minuteaccount cf its discovery and of his correspondence with De la FontainIX'ORGAK'IC CHEMISTRY. 13and Marignac on the subject. Basing his remarks on his own workand tdie spectroscopic examination by Soret, he now has no hesitationi n claiming mosandruin as a new element.On the Discovery of a New Earth announced by J. L.Smith. By C. MARIGSX (Co?72pt. reid., 87, 281-5283 ).-In thispaper Marignac points out the reasons leading him to the conclu-sion that Smith's " mosandrum " is identical with Mosander's " ter-bium ; " whilst the earth provisionally designated X by Soret and theauthor, differs from t,htl former in its absorption phenomena, althougliit shows nirt11~- points of resemblance with an earth described by De laFontaine of Chicago.J.AT. T.J. M. T.Magnetic Compound; having the Formula RO.Fe,O,. ByK. Llsr (Delcf. Clmn. Ges. Be,.., 11, 1512-1.516j.-Lime water pro-duces in a neutral solution of ferric chloride a brown precipitate,which is magnetic, and after ignition has the composition Cs0.Fe207.I n a similar manner magnetic compounds of magnesia and bnrytawith ferric oxide can be obtained. The corresponding manganese,nickel, copper, and lead compouuds are formed when soda is added toa solution containing ferric chloride and copper sulphatc, &c., in theirequivalent proportions. Magretic compounds are also formed whensodium or potassium carbonate is fused with ferric oxide. w. c. w.Dissociation of Metallic Sulphides. By P. DE CLERMOSTand J. PROMJI EL (Co??2pt. re72d., 87, 330, 332 j .-The decomposi-tion which ensnes on boiling certain sulpliides with water is regardedby the authors as due to the dissociation of a previously formedhydrate of the sulphide. They point out that freshly precipitatedsulphide of arsenic boiled with water gives rise to a more rapid evolu-tion of sulphuretted hydrogen than tlie same sulphide does when ithas previously been dried at 12.5". But if this last is kept in coutactfor some hours with hot water in a closed vessel, i t gives off sulphurettedhydrogen, when boiled in an opcn vessel, as rapidly a s the freshlyprecipitated sulphide. On boiling snlpliides with water in a vacuum,dissociation was observed to occur a t tlie following temperatures :sulphide of arsenic, 22' ; sulphide of iron, 56" ; sulphide of antimony,95". The dissociation of arsenic sulpliide presented ccrtain pecn-liarities, which the authors believe to be due to the interference of thearsenious acid, which is one of the products of decomposition. Thepresence of this substance impedes the dissociation, by the formation,as they suppose, of an oxpsulphide which undergoes dissociation moreSulphide of arsenic, to which crystallised arsenious acid has beenadded, is dissociated more quickly than that to which arsenious acidobtained by the dissociation of tlie sulpliide has been added. Asarsenic pentasulphide on dissociation yields arsenious acid and notarsenic acid, the author doubts its existence as a definite chemicalcompound. R. R.slowly