The magnesite industry in India

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Wrought I’lpe 11rainage

American Academic Locomotive lndian Institution

Iry J. J. Cosgro\e, Pittsburgh, 1409. Sybtcntx,” Pharmaceutical Association Proceedings, vol. 37, Ilaltimore, 19o9. Annuaire, Uruselies, Iyro. Royale de lielgique, and Carriage Superintendents Committee, hfliliated with the Railway Conference Association, Proceedings, Bombay, 19o9. of Engineers and Shipbuiltlcrs in Scotland, Transactions, vol. 52,

Glasgo\v,

1909.

Public Service Commission for the First District of Kcw York State, Proceedings, July I, 1907, to December 31, 1g0X, 3 ~01s. Iowa Geological Survey, Annual Report, vol. 19, Des Moines, 1909. National Association oi Cotton Manuiacturers, Transactions No. 87, Boston, 1910.

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Stamp Milling Machinery, Catalogue C, Colorado Iron Works Company. Ko. 6, Denver (n. d.). Risdon Iron Works. Gold Milling Machinery, Cataloguc No. 12. San Francisco(n. d.). Stamp) Milling Machinery, Catalogue, ,411enTaylor I31ginccrillg Company. tovvn

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TOPICS.

(Bu11. sm. d’Et1c02w., ‘I‘l1E :\C~I.IoN OF LL’AlIil< ON IX,\l, l’lrm. j. )-A!!. Olivicr Ferrier has received the award of merit of the Societc: de Pharmncic of I’aris for his treatise upon the action of \Vatcr such as that of Vitre, which water on lead and iron pipes. contains less than 3 niilligramnies of calcium carbonate per litre, does not deposit a protective layer on the interior of lead pipes, especially if there he free carbon dioxide gas present; the nitrates and chlorides present tend to form small quantities of lead chIoride, The which dissolves, and larger quantities of hydrocarbonate. author examines the behavior of different metallic pipes with waters containing but little lime. He concludes that lead pipes shouIc1 lx reHis jected, even when tinnrtl ; also iron pipes even when enamelled. conclusion is that it is desirable to change the composition of the water, as is done at .SlwffieId and at Dessau, where its action on pipes is attributetl to its too great purity, by adding a fixed quantity of lime, which has the further advantage of sterilizing the water, and of furnishing a mineralizin g element to the human body. 113,

THE MACNISSITE TNDUSTRY IN INDIA. i La Nature, No. 1922.)Considerable deposits of magnesite covering an area of motie than 800 hectares (1976 acres) are found at Salem in the Madras It esists in numerous irregular veins. The mineral I’residency. is almost perfectly white, its density is about 3, and its hardness about 5. Tt contains 96 to 97 per cent. of magnesium carbonate, and a wry little silica. chalk, and iron and aluminum oxides. By

calcining the magnesite in gas ovens at 8oa” C. magnesium oxide is obtained, which mixed with a solution of magnesium chloride, makes a very good cement. By heating to 1700~ C. calcincd rnagnesia is obtained from which refractory bricks can be made. A WHITE Br~\zr~\lc; S~I,DKI~ (B;clss il.orld) good fosr use on iron and steel consists of copper ~,i llcr cent., zinc 45 per cent., and nickel I0 per cent. ‘l‘hc nickel gives the necessary whiteness and I’or bi-azing ste’el or only raises the melting point very sliglitl\~. iron, silver solder, \vhich flo\vs readi!\- Miiliout oxidation and at a low temperature, is preferable. but on account of its cost ;I suitable substitute is sometimes desirable. THE lNJURIOUSNESS

STEA~L ~OIl.~.R FURbeen called to the danlaKe clone to the neighborhood by the production of smoke which contains corrosive or noxious gases, such as sulphuric or sulphurous acid or ammonia. To give an exact idea of the damage which such smoke can cause, samples should he taken at the base of the chimney to determine their composition. Sulphuric acid gas is retained in a suitable absorption appar:Il.us, ant determined as insoluble barium sulphate : sulphurous acid js determined in the same way after absorption and oxidation to snlThe proportion, by volume, 0.’ phuric acid bv iodine or bromine. sulphurous acid gas in the smoke varies 0.0001 to 0.0003 per cent. ; The content of ammonia, ammoit rarely reaches 0.001 per cent. niacal salts and volatile products in the smoke has littl: or no relation to the injury they do. Recently attention has been directetl to the smoke of locomotives, which tliffuses quantities of sulohuri~: and sulphurous acid gases into the atmosphere which are {‘at. front negligible. ON (Ltr

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(Lo nratllrc, x0. 1922. )-Attentionhas frequently

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DEcOMi~osITIoN OF CICLLUI.OII) WITIIOU~ Tl(NITIOK. g to Panzer the deconlp(lsitioI No. Io22.)-Accordin without ignition gives. for I oo Gm. :

‘Nitrogen dioxide. . . . . . . Nitrogen oxide. . . . . . . . . . Carbon diositlc. ......... Carbon monoxide. . . Nitrogen .. . . . . . . . . . . Camphor .. . . . . . . . Nitric acid. ... . .. Volatile organic matter. .. . Carbonaceous residue. . . . .

....... ....... ....... ....... ....... ....... ...... ...... .......

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1; 1-o:n The greater part of the camphor is fomd unch;~n:.c~r the investigations of the author it appears ‘:hat under 11~ c cr~utl tions the camphor acts as a tlenitrifier on tlie nitro-cc.11 111 c fornl-