ble portion of the superphosphate. In order to prevent the precipitation of calcium carbonate from any sulphate of calcium that may be present, the entire amount of calcium is precipitated by sodium oxalate, and the acidity of the resulting mono-sodium phosphate is determined. If free sulphuric or phosphoric acid is present in the superphosphate, sodium carbonate is added before titration, until the liquid becomes slightly turbid.

Mr. L. Marquardt has described a new method for the quantitative determination of fuseloil in brandy. The oil is extracted with chloroform, and the product is oxidized with bichromate of potash, distilled, and treated with barium carbonate. The chloroform and the excess of barium carbonate are removed, when the baryta and the barium chloride are determined by means of nitric acid. The quantity of amylic alcohol or fusel-oil is calculated from the baryta.

G. Larsen has shown that copper and zinc can be separated by one precipitation with hydrogen sulphide if hydrochloric acid is added to the hydrogen sulphide with which the precipitate is washed. Emil Berglund finds that the method holds good when the amount of hydrochloric acid added to the wash-water is smaller than recommended by Larsen, and further, that zinc is not precipitated with copper if the amount of hydrogen sulphide in the washwater is small.

Spring has communicated the results of experiments in producing sulphides by exposing various metals mixed with sulphur, both finely divided, to a pressure of 6,500 atmospheres. Magnesium after six pressings, each time being reduced to filings, gave a gray homogeneous mass baving a weak metallic luster. Zinc, after three pressings, gave a sulphide resembling the natural blende; iron, after four pressings, gave a block which was hardly touched by the file, and appeared homogeneous under the microscope. Cadmium sulphide was formed easily in three pressings, in a yellowish-gray, homogeneous mass. Bismuth sulphide and antimony sulphide were formed in two pressings, and lead sulphide still more easily; copper and tin yielded the sulphide in three pressings. Silver required from six to eight pressings before a homogeneous mass could be obtained. Alumisam and carbon gave imperfect results. Spring has drawn the conclusion from his experiments that allotropic states are only different conditions of polymerization, in which the chemical activity decreases as the process goes on. The method almost exclusively employed for estimating the halogens in organic compounds, that of Carins, consists in heating the substance in a sealed tube with fuming nitric acid and silver nitrate. R. T. Plimpton and E. E. Graves propose, in the case of volatile compounds, a method by which the substance is introduced into a U-tube through which illuminating gas and air are passed, as in a Bunsen burner. The volatile substance evaporates and burns with VOL. XXIII-8 A

the gas at a tip on one end of the tube, while the halogens are left partly free and partly in combination with hydrogen. The evaporation is sometimes aided by warming the tube with hot water or otherwise. The temperature is raised or lowered so that the substance may always be detected in the flame, yet not in sufficient quantity to make the flame luminous. The products of combustion are aspirated through a bent funnel tube and collected in dilute caustic soda; this is boiled with sulphurous acid to reduce chlorates, etc., and the halogens are then precipitated with silver nitrate. The success of the experiment depends upon the regular volatilization of the compound.

Mr. W. G. Strype, of Wicklow, Ireland, has devised a method of purifying the hydrochloric acid used in the manufacture of chlorine from sulphuric acid before admitting it into the chlorine-stills, by which the difficulties arising in this manufacture from the accumulation of calcium sulphate are to a large extent obviated. His process depends upon the fact that while calcium sulphate is somewhat freely soluble in hot hydrochloric acid, it is only slightly soluble in the cold acid.

Successful experiments have been made by M. J. Garnier at works near Rouen, France, with a new process for removing arsenic and antimony from copper. It comprises the employment of a sole of chalk and tar, over which, for each separate operation, is placed a false sole of limestone and manganese peroxide. With the melting of the copper, a generation of carbonic acid and oxygen begins from the upper sole, which oxidizes the charge. As soon as the metal is sufficiently liquid, the lime and manganese protoxide rise and dissolve the arsenic acid. By this one operation the amount of arsenic, according to M. Garnier, is reduced to one-fifth. Subsequent fusions with basic fluxes are said almost completely to eliminate the arsenic.

Dr. Sidersky bases a method for the separation of calcium from strontium on the statement that on adding a mixture of sulphate and oxalate of ammonium to a solution of strontium, the latter is all precipitated as sulphate; while, if the mixture is added to a calcium salt, only oxalate is precipitated. If it is added to a solution containing both strontium and calcium, the former is precipitated as sulphate and the latter as oxalate. The two precipitates are separated by the solubility of the oxalate in acids.

Otto F. von der Pfordten has published a new method for the estimation of tungstic acid by reduction with zinc and hydrochloric acid to tungsten dioxide. The reduction is best effected by using a 27-per-cent. solution of hydrochloric acid. The solution first becomes blue, then a black-green, and finally a dark brownish-red, the end product being tungsten dioxide, which is determined by titration with potassium permanganate. The method has the disadvantage that only very sinall quantities of

The Société de St. Croix at Lisle is manufacturing potash upon a large scale by the trimethylamine process, which is similar in principle to the ammonia process for the manufacture of soda. The latter process can not be used for the manufacture of potash, by reason of the too great solubility of hydro-potassic carbonate in solution of ammonium chloride. Bicarbonate of potash is, however, but very slightly soluble in chloride of trimethylamine. Besides the nature of the ammonia employed, the chemistry of this process appears to differ from that of the ammonia process also in the fact that, instead of using a bicarbonate as in that process, the sesquicarbonate, the highest carbonate of trimethylamine that can be obtained at present in a free state, is employed, and the reactions are more complex. The trimethylamine process is limited in its application, for it is available for the manufacture of potash only from potassium chloride, while the Engel process is efficient either with that salt or with the sulphate.

G. Archibald describes a new industrial method of preparing paper-pulp, which has been patented in the United States and Canada. Wood or straw is cut to pieces, macerated with milk of lime, transferred to a digester after twenty-four hours, and saturated with sulphurous acid, with the simultaneous application of a pressure of five atmospheres for one or two hours. The material is then washed with water and again treated under pressure with three per cent. calcium chloride and half per cent. aluminum sulphate. After these substances have been washed out, the pulp resembles cotton in appearance, and can be employed for manufacturing the finer grades of paper at once. The process requires about three hours after the treatment with milk of lime.

A.Houzeau and Fr.Goppelsroeder have traced the active agency in grass-bleaching, which Schoenbein ascribed to ozone, to peroxide of hydrogen. The proportion of this substance in the air was found to differ, according to a variety of circumstances; and the preponderating influence in its production is believed to be light. Atmospheric precipitations, particularly hoar-frost, contain considerable quantities of it; and the quantity that came to the earth within four months was found to amount to 62.9 milligrammes per square metre. The ordinary processes of open-air and wax-bleaching are attended with so many inconveniences in delays that the production of the effective agent in a concentrated form was suggested as a manifest remedy. The peroxide of hydrogen is superior to all other media for oxidation in bleaching, in that it can be used without inconvenience and without any danger of injuring the fiber. It may be concentrated from its solutions by freezing out, or by evaporation in a vacuum over sulphuric acid, at a temperature of from 59 to 68° Fahr. Diluted solutions of it are equal to solution of chlorine in effect, and will keep for months in a temperature not exceed

ing 77° Fahr., if protected from the light. All products which are to be bleached by this substance must be submitted to a preparatory treatment, the purpose of which is to render them capable in every part of being moistened with the watery solution.

Dr. Max Schaffner and Mr. W. Helbig, of the Aussig Works, Bohemia, have applied a process for recovering sulphur from alkali-waste, which, while it requires no acid, saves the whole of the sulphur originally contained in the waste, and in addition all of the calcium as carbonate. It includes three operations, the first of which consists in heating fresh waste with solution of magnesium chloride in a closed iron vessel furnished with a mechanical agitator, when two double decompositions take place-calcium sulphide and magnesium chloride into calcium chloride and magnesium sulphide; and a reaction of the last upon some of the water present to produce magnesia and sulphureted hydrogen. The sulphureted hydrogen is evolved in a continuous stream until the charge of waste is completely decomposed, and then there remains in the boiler a solution of calcium chloride holding in suspension an equivalent of magnesia. In the second operation, one third of the sulphureted hydrogen is burned into SO, and steam, and these products are mixed with the other two thirds and passed through a solution of calcium chloride, whence is derived a thin magına, consisting of solution of calcium chloride holding in suspension free sulphur. The third operation consists in injecting carbonic dioxide into the solution of calcium chloride, holding magnesia in suspension, which had been obtained as the residual product of the first operation, thereby reproducing the quantity of magnesium chloride which had been begun with, and at the same time regenerating all the calcium carbonate which had been employed for the production of the black ash, of which the waste had been one of the constituents. Mr. Alexander Chance, of Birmingham, has applied a modification of the third part of the process, by which all of the sulphureted hydrogen evolved in the first operation is burned, and the resulting sulphurous oxide is sent into the vitriol chambers, by which the cost of the process is reduced simply to the cost of the operation of reducing the magnesium chloride.

MM. Benker and Lasne have introduced a process for economizing nitrous compounds in the manufacture of sulphuric acid, which consists in the reduction of the nitric peroxide in the chamber gases before they reach the GayLussac tower into nitrous anhydride (N,O), which forms a stable compound with sulphuric acid. This is done by injecting into the conduit conveying the exit gases from the last chamber to the foot of the Gay-Lussac tower, a regulated quantity of sulphurous oxide, accompanied with just the quantity of vapor of water necessary to form, with the SO2+NO2, nitro-sulphuric acid. Another plan for accom

plishing the same object consists in making the gases which have traversed the ordinary Gay-Lussac tower afterward traverse several supplementary towers, supplied with weaker sulphuric acid than is supplied to the GayLussac tower itself.

Domestic Chemistry.-F. P. Hall, of the Massachusetts Institute of Technology, has published in the "American Chemical Journal" the results of some investigations on the corrosion of fruit-cans and tin-foil by the acids of the articles of food inclosed in them. Acetic, tartaric, and citric acids dissolved more tin and lead (in some cases twice as much) from sheets of pure metal than from alloys. In glass-stoppered bottles from which the air was as well excluded as it is from ordinary fruitcans, the action was less than in loosely-covered beakers, but still considerable. Three cans that had been emptied were let stand two weeks with acid in them, at the end of which time the tinning had been taken off up as far as the acid reached. There was dissolved by

Hence a can once opened should be emptied immediately, as corrosion thereafter takes place very rapidly. Analyses of the "bright plate" of which cans and other tinware are made, showed no admixture of lead in the tinning, and no tinware could be found made of "terne plate," the sort that is understood to be coated with an alloy of tin and lead. The solder of the cans, however, contains a large amount of lead, and vegetable acids act on this as well as on the pure tin of the plate.

Twelve specimens of tin-foil obtained from dealers were analyzed. Only three of these were sold for pure tin, and they proved to be as represented; the others, some of which were called "composition foil," gave from 60 to 95 per cent. of lead. Nine specimens that had been in use gave various results. Two from different kinds of compressed yeast contained no lead, and a piece of foil from a cake of chocolate bought at a street stand was also pure. A piece of embossed foil from a fancy cake of chocolate gave 80 per cent. of lead, and in two specimens from Neufchâtel cheese were found respectively 73.19 and 75.27 per cent. "The use of a foil containing about 75 per cent. of lead for wrapping the so-called Neufchâtel and other soft cheese is certainly reprehensible. Owing to the acid in or developed in the cheese, the foil becomes crumbly, and even when the cheese is first covered with greased paper, particles of the oxidized foil are very likely to become attached to the cheese as it is used."

Mr. William Thomson, F. R. S. E., having investigated a case of lead-poisoning arising

from the use of unsuspected water-pipes of lead, was induced to examine the merits of the tin-lined pipes. A pipe, the coating of which was from to of an inch thick, to his surprise, gave evidence of contamination to the water that passed through, and the lining was found to contain a large proportion of lead. A similar pipe from another manufactory revealed the same impurity. These pipes were found to have been made by pouring tin down the side of a strip of lead in introducing it as lining. In the course of the process the tin had dissolved a considerable quantity of lead. Such pipes are used to a considerable extent in drawing beer, and are in danger of contaminating the liquor, particularly that portion of it which, standing in them over night, is sold to the first customer in the morning. In another kind of lead pipe, called "tinned-lead pipe," the inside coating is made by filling the first few inches of the lead pipe, while still very hot, with molten tin, which remains molten and washes the inner surface of the lead tube as it is produced. The quantity of this "tin" increases as the pipe is drawn out, by melting the lead with which it is in contact and carrying it along, and ultimately the lining consists chiefly of lead. Mr. Thomson has observed that aerated waters are contaminated with lead much more often and in many cases to a much greater extent than would be expected, considering the pains which is taken in preparing the articles. Manufac turers admit the fact, but say that it is impossible to procure the substances free from metallic contamination at anything like reasonable cost.

M. Gustave Le Bon has been carrying on investigations upon the action of antiseptics, from which he concludes that the disinfectant power of any antiseptic appears to be the more feeble as the putrefaction is the more advanced. If an aqueous solution containing one tenth its weight of minced meat be taken as the normal solution, it will exhale during the first stages of putrefaction an extremely fetid odor, which, however, can be destroyed by a comparatively small amount of antiseptic. At the end of about two months new bodies with a special odor will be developed, which require for their destruction quantities of the same antiseptic at least twice as great as at first. If the power of antiseptics be measured by taking as a means of comparison their disinfectant properties upon a given weight of the normal solution already mentioned, the most powerful disinfectants will be shown to be potassium permanganate, chloride of lime, sulphate of iron acidulated with acetic acid, phenol, and the glyceroborates of sodium and potassium. There is no parallelism between the disinfectant action of an antiseptic and its action on microbes. Potassium permanganate, which is one of the most powerful disinfectants, exercises no appreciable action_on_microbes. Alcohol, which checks the develop

ment of microbes, exerts only a very feeble disinfectant action upon the products of putrefaction. There is likewise no parallelism between the power of preventing putrefaction and that of checking it when it has begun. Phenol and alcohol are excellent preservative agents, but have only a slight action upon putrefaction in progress; with the exception of a very few substances which are powerful toxic agents, such as mercuric chloride, the greater number of antiseptics, and notably phenol, have only a very feeble action upon bacteria. M. Le Bon even regards phenol as one of the best liquids which can be employed to preserve living bacteria for a long time. The experiments made upon cadaver alkaloids can not serve to decide the question as to whether the volatile alkaloids which give to putrefaction its odor are poisonous, for such experiments have generally been made by introducing into the system putrefaction prodacts containing bacteria, to which the effects observed may be attributable. M. Le Bon's experiments were made upon frogs placed in jars, at the bottom of which was a very thin layer of his normal liquid. At the beginning of the putrefaction the liquid, although it emitted a very fetid odor, swarmed with bacteria, and was very virulent if injected under the skin, had no appreciable effect upon the frogs; but the same liquid, two months old and no longer having virulent properties, killed in a few minutes the animals that breathed its exhalations. In fact, the virulent power of a body in putrefaction and the toxic power of the volatile compounds which it gives off seem to be in an inverse ratio to each other. The extremely minute quantity of the products of advanced putrefaction necessary to kill an animal by simple mixture with the air it breathes is a fact that shows these volatile alkaloids to be extremely poisonous.

Atomie Weights-Nilson has calculated the atomic weight of thorium from the sulphate, which he obtained from Arendal thorite by mccessive treatment with hydrochloric and #alphuric acids. The purified salt was twice precipitated with ammonia, and washed and dissolved in hydrochloric acid, and then converted into an oxalate and ignited. The snowwhite oxide was converted into sulphate, and this was allowed to crystallize by the spontaneous evaporation of its solution. Large, transparent, brilliant crystals were thus obtained, which were permanent in the air and had the composition Th(SO.),(H,O). For the estimation of the atomic weight a weighed quantity of the pulverized salt was heated to expel its crystal water, again weighed, and then again beated to a full white heat. The sulphuric oxide was entirely expelled, leaving the pare thorium oxide, which was again weighed. From the data thus obtained the atomic weight was calculated. Assuming the quadrivalence of thorium, the means of two series of observations are, respectively, 232-43 and 232-37.

Cleve, taking the mean of twelve experiments upon the synthesis of yttrium sulphate with pure material, proved to be free from terbia, has redetermined the atomic weight of yttrium to be 88.9±027, or, if SO,=80, then Yt=89.02. The last figure suggests a fairly close conformity with Prout's law.

Clemens Zimmermann has prepared uranium by reducing a mixture of potassium or sodium with chloride of uranium, by heating in a charcoal crucible. Thus prepared, its atomic weight has been calculated to be 240, or greater than that of any other known metal. Uranium has the color and luster of silver, but is harder, and gives out sparks when struck with a hammer. It oxidizes gradually when exposed to the air, burns when heated on platinum-foil, and is dissolved by nitric acid. Its specific gravity has been determined at 18.7.

Analytic Chemistry. The properties of hydrogen dioxide as an oxidizing agent have been found useful in a variety of analyses. It oxidizes arsenious acid to arsenic acid, and phosphorous acid to phosphoric acid, and decomposes hydrogen sulphide with the formation of water and free sulphur. If, however, it acts in ammoniacal solution, such as ammonium sulphide or sodium sulphide, the liquid becomes warm, and is gradually decolorized without deposition of sulphur; but that substance is instead oxidized to sulphates and hyposulphates. With sulphide of tin, antimonium and arsenic in ammonium sulphide, the addition of hydrogen dioxide causes oxidation of the ammonium sulphide, with at first precipitation of the other sulphides, ending, on the addition of an excess of the reagent and heating, in their more or less complete transformation into oxides. The conduct of hydrogen dioxide toward ammonium sulphide, or the action of hydrogen sulphide gas on ammoniacal hydrogen dioxide, may be employed in qualitative analysis for destroying an excess of those sulphides, and in quantitative analysis for determining amounts of gaseous or dissolved hydrogen sulphide, or for the determination of sulphur or metals in sulphides. The property of oxidizing hydrogen sulphide easily and completely in alkaline solution may be taken advantage of in the estimation of chlorine, bromine, and iodine in liquids containing hydrogen sulphide. Metallic sulphides which are oxidized directly by hydrogen dioxide may be estimated by the amount of sulphuric acid formed in the solution. Such metals are arsenic, antimony, zinc, copper, and cobalt. The estimation of metals by this means is capable of more extended application than the direct oxidation of the sulphide. Pure metallic sulphides are seldom obtained in analysis, but more frequently mixtures with free sulphur. The amount of free sulphur does not affect the quantity of hydrogen sulphide liberated by an acid, and hence the advantage of determining the latter. It is absorbed in a peculiar apparatus, described by the authors. Foremost among the metals that