140 Chemical Notices from Foreign Sources. We feel sure that every attentive reader of this work will agree with us in pronouncing it a most valuable contribution to sanitary literature. CORRESPONDENCE. DISSOCIATION OF NITRIC ACID. To the Editor of the Chemical News. SIR, Allow me space to correct an error in the report of the paper on "Dissociation of Nitric Acid," read before the Chemical Society on the 4th inst. In the third series of experiments it is stated that nitric acid containing nitrous acid was not decomposed on boiling, the reverse being the case. Nitric acid containing 0 123 per cent of N2O3 yielded o'3 c.c. of gas, that containing 128 per cent yielded 2 c.c. of gas of which 71 per cent was oxygen; but nitric acid containing no nitrous was boiled to dryness without any decomposi tion occurring.-I am, &c., 6, George Street, Bath, March 17, 1875. PHILIP BRAHAM. CHEMICAL NEWS, expressed in centimetres of mercury by F; and the volume CHEMICAL NOTICES FROM FOREIGN treated with soda, and distilled. The methyl-diphenyl SOURCES. NOTE.-All degrees of temperature are Centigrade, unless otherwise expressed. Comptes Rendus Hebdomadaires des Seances de l'Academie des Sciences, No. 7, February 15, 1875. New Researches on the Mode of Intervention of Electro-Capillary Forces in the Phenomena of Nutrition.-M. Becquerel.- Desirous of ascertaining the physico-chemical action exerted by water and salt-water upon tubers and fruits, the author has made several series of experiments, which lead to the following results:Water is constantly positive, and the fruit or the tuber negative, which indicates that the electro-capillary currents have the effect of oxidising the parts under the epidermis or the skin. With saline water the result is inverse. We see hence the effects which may be produced in living bodies by the introduction of different liquids, effects which should be taken into consideration in the application of the physico-chemical sciences to medicine. Depth and the Superposition of the Magnetised Layers in Steel.-M. J. Jamin.-The magnetic strata are limited to a certain thickness, which they can never exceed. This limit varies in different steels. It is very great in those which are soft, and diminishes as the proportion of carbon augments and as the temper is harder. For certain bars which the author has studied it is=O4; but he has specimens where it is below 1-10 m.m. The latter only receive what might be called a superficial magnetic coating, the thickness of which it is not possible to augment by increasing the intensity of the current. But if the depth of the magnetisation diminishes along with the magnetic conductibility, the intensity of the magnetism increases. It follows that the quantity of magnetisation is subject to two causes of inverse variation-the depth which increases, and the intensity which lessens as the conductivity increases. Certain Mechanical Properties of Saturated Steam. -M. C. Antoine.-Between the temperature, the tension, and the volume of steam we may establish certain relations of great simplicity. If we designate the temperature of the steam in degrees C by t; the maximum elastic force of the steam, in atmospheres, by p; the same elastic force Action of the Chlorides of Alcoholic Radicals on the Secondary Monamines.-M. Ch. Girard.-Allow to react in cast-iron enamelled autoclaves, or in tubes, for ten to twelve hours at 200° to 250° C., 100 kilos. diphenylamin, hydrochloric acid (sp. gr. 1'17) 68 kilos., and pure methylic alcohol 24 kilos. The pressure may amount to 10 to 15 atmospheres. The mixture when cold is decanted, amin which distils over is still contaminated with a little diphenylamin, which is removed by treatment with twice the volume of concentrated hydrochloric acid and agitation. The mass becomes hot, and on cooling deposits hydrochlorate of diphenylamin in crystals. These are thrown on a filter, and the liquid hydrochlorate of methyldiphenylamin is decomposed with water, and then neutralised with soda. The boiling-point of the purified methyl-diphenylamin is 282° C. To prepare ethyldiphenylamin, 30 to 32 kilos. of ethylic alcohol are used instead of the methylic directed above, the proportions of diphenylamin and of acid remaining the same. It is an oily liquid, and distils over at about 295° to 297°. It is coloured violet by nitric acid, and forms a crimson solution in water. It yields dyes with many oxidising agents. Amyl-diphenylamin is prepared and purified like its two lower homologues. It is likewise of an oily consistence, and distils at 330° to 340°. Nitric acid produces with this base a blue-slate colour, resembling that given by diphenylamin. All these bases can be transformed into blue dyes by heating with oxalic acid from 120° to 130° for fifteen to twenty hours. The yield of colour is very abundant. The tinctorial bodies formed are freed from excess of base by successive treatment with benzol, ether, petroleum, and alcohol, in which last liquid these blues are unfortunately very sparingly soluble. Pure diphenylamin is also converted into a blue dye by the same treatment, as proved in 1866 by the author and M. de Laire, and may be purified in the same manner. It is more soluble in alcohol than the blues produced from the tertiary monamines. These dyes may, however, be obtained in a state soluble in water by heating either diphenylamin or the tertiary monamines with a mixture of oxalic and sulphuric acids, at temperatures not exceeding 140°. The soluble blue dye, thus prepared, is easily freed from any excess of base. Advantage is taken of the different solubility of the calcareous salts of the sulphoconjugated acids produced in the reaction, those of the blue compound not having the same properties as those of the secondary and tertiary monamines. The sulphoconjugated acids of diphenylamin readily reproduce this base. Action of Chlorine on Perbromide of Acetylen.-M. E. Bourgoin.-The final result is the same whether these substances are allowed to react in sunlight or in darkness: the hydrogen and half the bromine are replaced by chlorine, tion (1 grm. of zinc in 15 c.c.), heated to 186°. In this The results were satisfactory as to shade, but the author Quantity of Neutral Fatty Bodies Remaining in Fats after Saponification.-M. Birnbaum.--Fats are saponified industrially either by water under pressure, or by dilute sulphuric acid in open vessels. The quantity of neutral fat remaining after industrial saponification is estimated by the quantity of glycerin set free by the action of caustic potash. An indigenous tallow, heated with water for ten hours at 14 atmospheres, and then saponified with potash, yielded o'094 of glycerin in 8.355 parts, corresponding to the following percentage composition:Water 0'26 .. 10.90 New Treatment of Commercial Nickel so as to obtain a Pure Sulphate of Nickel, without the use of Sulphuretted Hydrogen or of Ammonia.-M. A. Terreil. -The salts of nickel employed in the electro-deposition of that metal are prepared from commercial nickel, which is an alloy of nickel, copper, and iron, with traces of arsenic, containing from 40 to 90 per cent of actual nickel. The author's process consists of four operations-solution of the crude metal in acids; precipitation of the copper by iron; peroxidation of the iron, and conversion of the metals into sulphates; precipitation of the iron by carbonate of baryta, and crystallisation of the sulphate of nickel. The nickel is first dissolved in seven to eight times its weight of aqua regia; the solution is evaporated almost to dryness; the residue is re-dissolved in water, using about five times the weight of the nickel employed. A little arseniate of iron remains insoluble, and is removed by filtration. Metallic iron, preferably small nails, is introduced into the hot liquid, to about the weight of the nickel employed. It is stirred from time to time to detach the copper from the iron. As soon as a piece of bright iron, introduced into the liquid, is no longer coated with copper, this process is complete. The whole is thrown on a filter, and washed repeatedly. The copper is then collected by sifting it under water, in a sieve coarse enough to let pass the coppery metallic powder, but retain the iron. The copper is dried, and is then marketable. The filtrate now contains merely nickel and iron. The latter is peroxidised, either by a current of chlorine, or by treatment with nitric acid. Sulphuric acid at 66° B. is then added in the proportion of 2 parts to I of nickel employed, and the whole is evaporated to dryness to expel nitric and hydrochloric acids. The dry residue is re-dissolved in water, a part sometimes remaining insoluble, consisting of sub-sulphate of iron. From the solution the iron is thrown down by means of carbonate of baryta (artificial precipitated). This carbonate separates the iron as sesquioxide, and forms at the same time insoluble sulphate of baryta, without acting upon the sulphate of nickel. The last traces of arsenic are thrown down along with the sesquioxide of iron. The precipitation is effected by gradually adding a slight excess of carbonate of baryta to the liquid, slightly heated, but not so as to exceed 50° to 60°. It is complete when a further addition of carbonate occasions no effervescence, and does not become covered with peroxide of iron. Pure sulphate of nickel then remains in solution. It is separated from the precipitate by filtration, and the filtrate is evaporated till a pellicle Preparation of Colourless Crystalline Carbolic Acid. appears on the surface, when it is set aside to crystallise.-M. Schnitzler.-Raw phenate of soda is strongly heated Reaction of Bromide of Ethylen on Dilute Alcohol in Presence of Acetic Ethers of Glycol.-M. E. Demole. -Not adapted for abstraction. Determination of Albumen by Tannin.-The determination of albumen by a standard solution of tannin does not give correct results, since all kinds of albumen do not combine with the same proportion of the reagent. Thus, that found in Bright's disease retains 37 per cent of tannin, but that met with in accidental cases of albuminuria, only 28. To determine albumen by means of tannin, it is necessary to add to the albuminous liquid, half its volume of a solution containing 26 per cent of common salt. Solution of tannin is added till all the albumen is thrown down. The whole is filtered, washed with water till free from salt, the tannin removed by means of boiling alcohol, and the residue dried and weighed. Neutral fats 88.57 99'73 A grease from New York, treated seven hours at 14 atmo spheres, and then re-treated, gave .. Water First Treatment. Second Treatment. .. 0.38 14:37 O'II 13.08 85.17 86.11 99'92 99'30 The in a copper still. Water, naphthalin, oils, and a little Reimann's Farber Zeitung, No. 4, 1875. Preparation of Magenta without Arsenic.-M. Bibanow. The author has tried Nicholson's process, This number contains an article on the prejudice against heating 3 parts of aniline (quality for red) with I part of green tarletans, which, as non-technical papers assert, are hydrochloric acid at sp. gr. 116, and 1 part nitric acid at got up with Schweinfurt green-a powerful poison. The sp. gr. 1'42, to 180° to 200°. The result was not satisfac-editor shows that this arsenical preparation is now supertory, the mass quickly turning to a dirty violet. He next seded by Guignet's green, which is perfectly safe. tried double salts of heavy aniline and of chloride of zinc. There are receipts for a green for calico; for dyeing The experiment was made with a mixture of 120 grms. of felts; and for a logwood blue on cotton yarns. heavy aniline; 100 of hydrochloric acid at 116; 30 grms. of nitric acid at 1'43; and 90 c.c. of zinc chloride in solu-1-60th part of chloroform. Burning petroleum can be extinguished by adding to 142 No. 5, 1875. Patents. Dyers in Berlin and other parts of Germany complain of the stringent regulations of the sanitary police. They are compelled to run their effluent waters into large tanks and to purify them with lime-a process which certain experts have pronounced impracticable upon the large scale. Manufacture of Alizarin.-The manufacture of alizarin has hitherto been checked for want of the raw material, since anthracen, which is converted first into anthrachinon and then into alizarin, is found only to a small extent in coal-tar. There is now a prospect of obtaining the raw material in quantity. Phthalic acid, C16H406, is produced by oxidising naphthalin. Benzol, C12H6, is well known to be an abundant constituent of coal-tar. If the chlorine compound of phthalic acid, C16H404 Cl2, is heated for twelve hours with benzol to 220° C. in a closed vessel, anthrachinon is obtained according to the following reaction: ABRIDGMENTS OF PROVISIONAL AND COMPLETE An improved process for the preservation of meat, fish, and other articles of food, and similar perishable substances. Claudius Stibbard Clark, Hind Street, Poplar, Middlesex. May 23, 1874.-No. 1837. The said invention relates to the preservation of meat, fish, poultry, game, and other articles of food, and similar perishable substances by treating them with a liquid or solution of bisulphite of lime, limestone crystallised sugar or other saccharine matter, saltpetre, and common salt. Improvements in the production of nitric acid. Eustace Carey Prentice, of the firm of Prentice, Brothers, Stowmarket, Suffolk. May 25, 1874.-No. 1841. This invention consists, first. in the admixture and incorporation with the nitrates, such, for example, as the nitrate of soda, or with nitrate of potash, to be decomposed by means of sulphuric acid for the purpose of effecting the production of nitric acid, of oxidising agents; such, for example, as the chlorates. Chlorate of potash, for example. Permanganates or manganates of the alkalies, or of the alkaline earths, or the peroxides; for example, the peroxide of manganese Chromic acid, the chromates and the bichromates of the alkalies and of the alkaline earths, and of such metallic oxides and compounds as shall, by the action of sulphuric acid and by the presence of the lower oxides of nitrogen, be capable of elevating the same from a lower to a higher degree. Secondly. Or instead of adding to the nitrates either of soda, potash, or lime the whole or a portion of the oxidising agents necessary to convert the lower oxides of nitrogen into the higher oxides or into nitric acid, I add such oxidising agents to the sulphuric acid to be employed for effecting the decomposition of the nitrates, and employ such admixture for effecting the decomposition of the nitrates, and for the production of nitric acid. Thirdly. The employment of oxygen in a pure or in a concentrated form, such, for example, as that obtained by the heating of peroxide of manganese and chlorate of potash, in admixture with the products which are evolved in the production of nitric acid from nitrates by the action of sulphuric acid upon the same. Fourthly. The employment in the production of strong nitric acid of an intermediate or secondary vessel containing sulphuric acid, in conjunction with any of the beforementioned oxidising agents, so as to effect the conversion of the lower oxides of nitrogen into the higher, and thereby increase the yield of the nitric acid. Fifthly. The employment of any of the beforementioned oxidising agents in conjunction with nitric acid, containing the lower oxides of nitrogen, so as to convert the same into the higher oxides, or into nitric acid. Sixthly. The treatment by the admixture of any of the before-mentioned oxidising agents, of a mixture of nitric acid and of sulphuric acid resulting from the production of gun-cotton or from other sources, such acids containing organic or other matters or compounds as cause the decomposition of the nitric acid upon the application of heat. Improvements in the manufacture of artificial yeast-powder and prepared flour of a self-raising character. John Henry Johnson, Lincoln's Inn Fields, Middlesex. (A communication from Edward Peers Eastwick, New York, U.S.A.) May 26, 1874-No. 1846. This invention consists in the manufacture of a new compound to be used CHEMICAL NEWS, in connection with any kind of flour or amylaceous matters intended for culinary purposes. The said compound or mixture is composed of neutral and acid salts in the proportion and for the purpose hereinafter more fully specified. The chemicals which may be used are the carbonates (acid or neutral). of the alkalies and alkaline earths, soda, potassa, ammonia, lime, &c., and the neutral or acid or double sulphates of alumina (alums), or any other salts which by their decompositions precipitate alumina, and by which alums may be formed, and sulphates (of the carbonate used) and free carbonic acid gas are produced. A mixture of two or more carbonates and a sulphate or other salt of alumina can be used, and will give a similar reaction as when only one carbonate is used. Improvements in ebullioscopes. Alexander Melville Clark, patent agent, Chancery Lane, Middlesex. (A communication from Pierre Marie Edouard Malligand, and Marie Euphrésine Elizabeth BrossardVidal, both of Paris) May 29, 1874.-No. 1885. This invention relates to various improvements in instruments known as ebullioscopes, or ebullition alcoholometers. (1) To maintain the liquid in a constant condition during the whole time of testing. (2) To provide means for reading off the mercurial column with greater precision. (3) To verify the accurate calibration of the thermometer. (4) To provide an accurately calibrated mercurial thermometer. (5) To a method of graduating ebullioscopes of any description. (6) To heating the ebullioscope in detail, instead of directly, so as to obtain perfect regularity [in the boiling-point of each liquid]. (7) To provide a deflector for preventing the tumefaction of the alcoholic liquids during their ebullition. (8) To immerse the bulb of the thermometer in the steam of the boiling water instead of in the water itself, so that the latter may not affect the result. Improvements in the treatment of phosphates of lime, and in the production of valuable products thereby. Benjamin Tanner, F.C.S., North Strand, Dublin. June 2, 1874.-No. 1915. This invention consists in certain improvements in the treatment of phosphates of lime whereby valuable products are obtained in an economical manner, and of such character and composition as may be desired. Any of the ordinary forms of phosphate of lime of commerce, or any other form of phosphate of lime, or any mixture thereof, is or are heated with hydrochloric acid, and solutions thereof obtained. The solutions obtained as before mentioned are treated with sulphuric acid in such quantity as to combine with the whole or any part of the lime or calcium in the solution, whereby the latter is precipitated in the form of sulphate of lime, and then separated by known means. The liquid portion is again employed as a solvent for the phosphate of lime, and the treatment with sulphuric acid repeated, the lime or calcium removed, and the liquid portion again employed as a solvent for phosphate of ime, the resulting solution being evaporated in furnaces. The relative proportions of lime or calcium and phosphoric acid having been ascertained, sulphuric acid is added to the mass, so as to leave, approximately, for every 71 parts of phosphoric acid 28 parts of lime or 20 parts of calcium. The dry product is useful as a manure. Instead of employing sulphuric acid as before mentioned, either of the alkalies, or their salts in conjunction with sulphuric acid, may be employed. The dry product will contain, in addition to the phosphate of lime, s lts of the alkali or alkalies. Phosphoric acid of any desired degree of concentration is obtained according to the number of times the acid liquor is caused to dissolve any of the forms of phosphate of lime, and is subsequently mixed with sulphuric acid in such proportion as to combine with the whole of the lime or calcium present, and the solution may be treated with alkalies or alkaline salts. The character and composition of the products are regulated by the proportions of the phosphate of lime and the acids, alkalies, and alkaline salts. Improved at paratus for extracting greasy and fatty matters from various waste substances. William Edward Newton, civil engineer, Chancery Lane, Middlesex. (A communication from Frederick William Ralph, Brussels, Belgium.) June 4, 1874.-No. 1951. The object of this invention is to produce a simple and inexpensive apparatus in which bisulphide of carbon may be used for dissolving out and extracting fatty and oleaginous matters from various waste substances, such as cotton-waste, which has been used for wiping and cleaning machinery from the oil that will become spilled thereon The apparatus which forms the subject of the present invention is so constructed and arranged that the escape of the bisulphide of carbon is practically impossible; and when it has been separated by distillation or otherwise from the fatty matters, it can be used over and over again. W. Greaves.-(1) Girard et de Laire's book is not pub'ished in English; (2) the CHEMICAL NEWS is the only journal likely to contain information on the subjects you name. W. L.-Your" Solar Speculations" are mere speculations, with no proof or authorities. What reason have you for saying that heat and gravitation are convertible into one another? M. L. Our rule is not to insert letters unless we know the writer's name and address. The words" in the boiling-point of each liquid" are found in the copy of the Abridgment delivered by the applicant, but do not appear in the original Abridgment. THE author states that the most remarkable physical IN a previously published series of experiments (Poggenproperty of silver-copper alloys is a molecular mobility, in dorf Ann., 136, p. 51), I have shown that the reduction of virtue of which certain combinations of the constituents the oxides of platinum, gold, silver, mercury, copper, of a molten alloy become segregated from the mass, the lead, antimony, arsenic, tin, nickel, cobalt, iron, and manhomogeneous character of which is thereby destroyed. ganese, by means of hydrogen, depends on the temperaThese irregularities of composition have long been known, ture, in so much that each oxide is acted upon by and reference is made to them in the works of Lazarus hydrogen from a certain degree of heat upwards. This Erckern (1650), and of Jars (1774). A very complete degree was found constant in all experiments with one memoir was published in 1852 by Levol, who did much and the same oxide, but differed for every metallic oxide towards ascertaining the nature and defining the limits of examined. Even the modications of certain oxides, in this molecular mobility. He discovered the important In connection herewith, I have tried how far it is poscase of tin and mercury, could be thus distinguished. fact, that an alloy containing 7189 per cent of silver is uniform in composition. Its chemical formula (AgCu2) sible, by maintaining the temperature at a certain point, and peculiar structure led him to conclude that all other to determine quantitatively the ingredients of a mixture of metallic oxides. alloys are mixtures of this, with excess of either metal. As previously, the reduction was The electric conductivity of these alloys was studied in performed in an elbow-shaped tube, the shorter and fused1860 by Matthiessen, who doubted the accuracy of Levol's up limb of which contained the oxide, and was heated in theory, and viewed them as "mechanical mixtures of a sand or paraffin bath; whilst the other open limb was allotropic modifications of the two metals in each other." plunged into water or mercury. The disappearance of The author then described the experiments he madec.c. of hydrogen, equivalent to less than 0.2 milligrm. with a view to determine the melting-points of a series of oxygen, could thus readily be observed. In all the oxides these alloys. He adopted Deville's determination of the the remarkable fact was perceived that after some timeboiling-point of zinc (1040° C.) as the basis of the inquiry, festly slackened, so that in spite of the much smaller quanin one case, e.g., after an hour-the reduction was maniand ascertained by the method of mixtures the mean specific heat of a mass of wrought-iron between o° C. and tity of oxide now present, a distinctly smaller percentage the melting-point of silver, which, as Becquerel showed, of oxygen was given up to the hydrogen in the same time. This retardation of the process of reduction is not is the same as the boiling-point of zinc. caused by a molecular change of the oxides in consequence of the heat, since prolonged application of heat previous to reduction is without influence on the duration and course of the process. Nor is it due to a change in the hydrogen, for a bulb-tube containing the oxide, and continually traversed by fresh hydrogen, showed the same reaction. Nor does it spring from the particles of reduced metal mixed with the oxide, since oxide of mercury, whose metal is deposited away from the oxide, shows the same phenomenon. As a higher temperature is not required for removing the last residue of oxygen, I was led to the supposition that, with the same absolute distance of oxygen and metal in the oxide, the reductionmovement of adjacent particles produced a new arrangement of the two elements which hinders the action of The mean of three experiments, which were closely in accordance, gave 015693 as the specific heat; and it should be pointed out that this number includes and neutralises several errors which would affect the accuracy of the subsequent experiments. The melting-point of each alloy was then determined by plunging an iron cylinder into it and transferring the iron to a calorimeter. These melting-points varied from 840° C. to 1330° C., or through a range of 490° C. The alloys which occupy the lowest portion of the curve contain from 60 to 70 per cent of silver. The results are interesting, as they show that the curves of fusibility and electric conductivity are very similar. The author states that, in studying the phenomena of liquation, the alloys were cast in red-hot moulds of firebrick in which the metal (about 50 ozs.) could be slowly and uniformly cooled. The results showed that the homogeneity of Levol's alloy is slightly disturbed by this method of casting; and, on the other hand, that alloys which contain more than 71.89 per cent of silver hardly shows signs of rearrangement, when the solidification is gradually effected. Two alloys were examined, which contained 630 and 333 per cent of silver respectively. Both were found to be far from homogeneous. In the case of the former the arrangement was influenced by gravity, the base of the casting being rich in silver. The density of pure silver and of Levol's homogeneous alloy, while in the fluid state, were then determined by the method described by Mr. Robert Mallet+; the metals being cast in conical vessels of wrought-iron. results obtained were as follows: Pure silver The Density fluid. Density solid. Abstract of a paper read before the Royal Society. + Proc. Roy. Soc., vol. xxiii., p. 209. hydrogen gas. This phenomenon is of more general Occurrence. According to the observation of L. Bell (CHEMICAL NEWS, vol. xxiii., pp. 258, 267), the reduction of metallic oxides by carbonic oxide takes a similar separation of cobalt and manganese by reducing chloride course. H. Rose, in his" Manual," when speaking of the of cobalt with hydrogen gas, refers to the difficulty of completing the reaction. In the behaviour of zinc, copper, tin, lead, and mercury, when heated in the air, the difficulty of converting the last traces of metal into oxide seems to be a kindred phenomenon. Since the reduction takes up a long time, it was necessary to examine whether by prolonged heating of oxides even below their reduction point, a perceptible quantity of hydrogen might not be taken up. Oxide of copper was heated for 14 hours, 50° below that temperature, and oxide of lead for several days, 100° below the point, in contact with hydrogen, without any action. At this temperature, therefore, the oxides may be regarded as un composable. If heated up to a temperature near reduction-point, and observed for an hour, a decre 144 Manufacture of Caustic Soda. the hydrogen was observed, augmenting more and more as the temperature rose. Since, however, an important action only takes place at the point of reduction, the determination of oxides, according to the proposed method, remains practicable, and the examination of the several determinations was undertaken. The mixture of oxides was obtained either by precipitation from mixed solutions, or by evaporation and ignition of the nitrates. Heat was applied to the reductiontube by means of a sand-bath, with a thermo regulator. The experiment is completed when the height of the water closing the open limb of the tube remains constant. The result of the experiments was as follows:— 1. Copper and zinc. End of the experiment after 5 hours; found 0034 grm. oxygen of the copper oxide. Calculation required o'0338 grm. 2. Copper and silver. Duration 45 hours; found 2019 instead of 20.5 milligrms. 3. Copper and bismuth. 26 hours; 20°2 instead of 20 milligrms. 4. Copper and cadmium. 28.5 milligrms. 22 hours; 284 instead of 5. Copper and lead. 45 hours; 19'2 instead of 18.8 milligrms. 6. Copper and tin. milligrms. 9 hours; 123 instead of 12'4 7. Silver and iron cannot be determined, their oxides forming a chemical combination. 8. Silver and lead could not be determined. 9. Arsenic and antimony could not be determined. 10. Mercury and iron. 25 hours; 19.6 instead of 20'5 milligrms. 10 and 26 hours; 17'5 11. Copper, iron, and zinc. instead of 17.6 and 16.8 instead of 16 milligrms. 12 and 2 hours; 12. Copper, cadmium, and zinc. 24.2 instead of 25.2, and 11.2 instead of 109 milligrms. 13. Copper, tin, lead, and zinc, could not be jointly determined, though it was possible to determine copper, tin, zinc and copper, lead, zinc. 14. Copper, manganese, iron, and zinc. The method was found inapplicable. It appears that oxides, even when jointly_precipitated from a solution, remain uncombined.-Berichte der Deutsch. Chem. Ges. zu Berlin. {CHEMICAL NEWS, April 2, 1875. ESTREMADURA PHOSPHORITE. By Dr. B. C. NIEDERSTADT, FOR the last two or three years a mineral substance containing phosphoric acid, and used as manure, has been imported to our market from Spain. It is found in the province of Estremadura, especially in the neighbourhood of Logrosan, and is obtained by mining. It appears in the market in pieces, the size of a fist, knotty, and is hard as stone, of a yellow-reddish colour. Hamburg, March, 1875. 2'155 99.961 Phosphoric acid 29'455 It is found in considerable quantities; and the facility of importation to Hamburg has rendered it an extensive import article, amounting in the year 1872 to 11,000 kilos., and more than 100 cargoes have already been imported. This mineral is greatly to be preferred to Lahn phosphorite ON THE MANUFACTURE OF CAUSTIC SODA. (which contains 3 to 6 per cent iron oxide, and 1.5 per cent aluminium oxide), because, in consequence of the trifling quantity of the materials above mentioned, it is not exposed to the risk of the phosphoric acid becoming insoluble, which is generally the case. The percentage of phosphoric acid, as shown in various investigations, is considerably reduced by a preponderating quantity of quartz; and scarcely amounts to 28 per cent, as proved by various experiments. When compared with the most valuable sorts of guano -such as Baker, Curacao, and Bolivia-which contain By JOHN MORRISON, F.C.S. THE third branch of my subject I am compelled to treat * A Paper lead before the Newcastle-upon-Tyne Chemical Soci In the |