effects, first, a saving of fuel equal to the amount which is required to convert this pulverized water into steam; and, second, a cooling of the chambers equal to the loss of the amount of heat which would have been generated by the combustion of the coal thus saved. To form this spray an atomizer is employed, in which a small body of steam is made to escape from a platinum jet, under a pressure of about two atmospheres, into the centre of a flow of water. With this device, twenty pounds of steam will convert eighty pounds of water into the finest spray. The jets are arranged in the sides of the chambers about forty feet apart. They are supplied with water from a tank above, while the steam is taken either from the steam-pipes already existing between the chambers, or from smaller ones put in their place. The saving in coal effected by the introduction of this simple device is estimated by a large manufacturing company that has employed it for some time to be two thirds of the quantity formerly burned; or, to estimate it differently, the savings in steam, acid, nitre, and labor during three months amounted to five shillings per ton of acid. The following bleaching processes are recorded by Bracke busch, who refers to the fact that the methods generally in use are not satisfactory. (1.) Cotton and linen tissues are brought in contact with oxide of zinc dissolved in lye of potash or soda. In this process there is no bleaching, properly so called. The oxide of zinc combining with the textile fibre merely masks the natural color of the latter, or perhaps forms colorless compounds with the coloring matters present. In connection therewith, it is noted that the alkaline liquids employed may affect the tissues. (2.) It has been proposed to bleach wool and silk by immersion for an hour in a solution of one part common salt, and one part oxalic acid, in fifty parts of water. The influence of the oxalic acid is certain, though unexplained. (3.) Tessié du Motay takes about equal parts of the permanganate of soda and of sulphate of magnesia, and dissolves them in lukewarm water. The tissues, previously freed from grease, are immersed in this bath until they are covered with a brown coating. They are then placed in a bath of sulphuric acid at four per cent., and rinsed after the brown matter is removed. They may be finally passed through

sulphurous acid. (4.) Ramsay's bleaching bath is formed by sprinkling with water equal parts of chloride of lime and sulphate of magnesia, by which process the hypochlorite of magnesia is produced. This last process is highly spoken of.

Upon the subject of ozone, Dr. Hofmann offers this stimulus to investigators in his late "Report on the Development of the Chemical Arts during the last Ten Years:" "How great would be the influence of a cheap source of ozone upon manufactures appears at once from the fact that in the nascent state this body oxidizes nitrogen to nitric acid. The presence of the latter body in thunder-rain has long ago been found to result from this circumstance. The manufacture of ozone would therefore involve nothing less than the synthesis of this important mineral acid, obtained hitherto only from nitre. That in grass-bleaching and in disinfection by means of ethereal oils we have from time immemorial made use of ozone-generated in the one case by the growth of grass, and in the other by the hydrocarbons -can only serve to intensify our longing for the technical production of ozone." Dr. Hofmann refers also to the fact that the first patent for the application of ozone was recently granted in England, for the purpose of forming acetic acid from alcohol without fermentation. The inventors (Turner and Vanderpool) obtain ozone by blowing air through a flame, and bringing it in contact with a current of alcohol. A very similar process for obtaining ozone was patented in this country, it may be added, by Dr. Loew, but no account of its practical application has thus far transpired.

The Chemical News, in its notes from foreign sources, affords the following information concerning Hofmann's process of utilizing iron pyrites. It is well known that the sulphur employed in the manufacture of sulphuric acid was formerly obtained from Sicily in its native state. In consequence, however, of the considerable increase in the export duties levied thereon during the last twenty years, the attempt was successfully made to supersede the sulphur by iron pyrites. The extraction of these pyrites is only found profitable where they occur in large masses. The residues likewise contain such large proportions of iron (about forty

per cent.) as to entail large losses therefrom by the works, while the quantities of the same are so great as to render it difficult to find room for them. Dr. Hofmann has devised the following process for utilizing them on a large scale: The residues undergo a systematic washing, the temperature of the water being about 40° C. (104° Fahr.). To the washings thus obtained salt is added in the proportion of one equivalent for each equivalent of sulphuric acid present in the liquid. The result is sulphate of soda, which is separated by cooling and crystallization. This product has numerous industrial applications, especially in the glass trade and in the soda manufacture, and it is obtained in the present case in quantity sufficient to cover the cost of all the operations. The mother-liquors remaining after the sulphate of soda has been separated contain zinc chloride, salt, sulphates of iron and of zinc, and a further quantity of sulphate of soda. By concentration to 54° B., the various salts are deposited with the exception of the zinc chloride, which may then be separated. It has several well-known industrial applications, and commands a good price. Or it may be worked for metallic zinc, by being first treated with lime to convert it into zinc oxide.

The residue containing the iron originally present in the pyrites, still impurified with some sulphur, is dried for some days in the open air, when the bulk thereof crumbles to powder, though there remain also compact fragments. With regard to these masses, Dr. Hofmann has observed that the pulverulent portions are almost free from sulphur, which is almost completely contained in the more compact fragments. A simple process of sifting suffices to separate the portion free from sulphur, which is then ready for metallurgical treatment as an iron ore.

Professor Henry Wurtz has succeeded in devising a very practical gravimetric method of gas analysis as a substitute for the volumetric methods generally employed. The method which he recommends and which he has developed with special reference to the investigation of illuminating gases-is founded on the general principle of submitting a slow current of the gas to be investigated to the action of a series of agents, so selected and combined as to absorb and separate in succession, each by itself, the different proximate

constituents of a gaseous mixture, converting each into a solid or liquid form, in which condition they can be weighed on a balance. Professor Wurtz alludes in his memoir to the fact that gravimetric methods for gas analysis were successfully employed by chemists some thirty years ago, and expresses his surprise that so little has been done to develop their capabilities. The general outline of his method is about as follows: In a crude coal gas, as drawn from the hydraulic main, the gas-chemist should be able to separate and determine with precision the following: (1) Tar, suspended in the form of spray; (2) Water, do.; (3) Water, as vapor, dissolved in the gas; (4) Naphthaline (condensible); (5) Other condensible hydrocarbons; (6) Smoke and soot (with dust); (7) Ammonia; (8) Carbonic acid; (9) Sulphureted hydrogen; (10) Carbonic oxide; (11) Oxygen (intermixed air).

Of these eleven proximate constituents, Professor Wurtz affirms that he has succeeded in separating with very satisfactory sharpness Nos. 1, 2, 3, 6, 7, 8, 9, and 11, eight in all, besides approximating to No. 4 the naphthaline in excess. Nos. 5 and 10 are still subjects of experiment. The following are the devices and manipulations employed: First. Arresting suspended matter by means of empty dry flasks, and straining through cotton previously desiccated. Absorbing next the ammonia, by means of re-agents which act on no other ingredient. Next, drying the gas with calcium chloride, which, ammonia being absent, may now be done. Next, taking up the sulphureted hydrogen by a normal metallic salt, so selected or so managed as to give up no water or acid vapor to the desiccated gas. Next, using sodic hydrate to absorb the carbonic acid, with certain precautions. Next, alkalized pyrogallol, or other suitable agent, to absorb oxygen, arranged so as to lose no water. The final (rough) measurement of the gas is then made at an observed temperature by a gas-meter. whole process is finally completed by a process of distillation, either at the ordinary or higher temperature in a current of the same gas analyzed, that has been subjected to similar treatment, and thus freed from all the ingredients to be separated from each other. After final weighings, the correct initial volume of the gaseous mixture is calculated

The

from certain formulæ derived from the crude meter-indications and the final weighings. For further details, we refer our readers to the memoir in full (vide Journal of the Franklin Institute, Vol. LXIX., p. 146 et seq.).

Schering affirms that the burning of glycerine may be readily effected in any form of lamp which permits the flame to be brought directly above the surface of the combustible. A long wick will not afford a steady flame, because of the sirupy consistency of the glycerine. The flame of glycerine is, like that of alcohol, very slightly luminous; and as the latter is of great utility as a solvent, Schering was induced to experiment with the glycerine flame, with the view of substituting the latter for the alcohol flame for laboratory and other purposes. The results obtained were quite satisfactory.

The assertion of Raoult, that pure cane-sugar in aqueous solution, and with the complete exclusion of air and ferments, would gradually undergo inversion under the influence of light, has been called in question by Kreussler, who has repeated the experiment with every possible precaution. The last-named chemist asserts that a pure sugar solution, kept in glass tubes, the open ends of which were drawn out and sealed with the blow-pipe, after the air contained therein had been completely driven out, failed to respond in the slightest degree to Fehling's test for glucose. Where the air had not been completely excluded, however, the contents of the tubes upon examination indicated the conversion of from 52 to 90 per cent. of the cane-sugar into grape-sugar.

Albumen for printing purposes is said to be becoming scarce, and a new source of supply is greatly needed. The debasement of silks by foreign admixture, if we may infer from the comments of journals devoted to textile interests, has of late reached such a height as to promise shortly to rival that of a class of cotton-goods which have added largely to the notoriety, if not to the fame, of one of the manufacturing centres of England. A writer to one of the French journals shows that the weighting of black silks-which began with the modest aim of making up for the loss sustained in ungumming-is now carried to the extent of 100, 200, and 300 per cent. This increase of weight is effected by treatment with salts of iron and astringents, salts of tin and cy