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TABLE OF CONTENTS.
PAGE
I.CHEMISTRY AND METALLURGY.—[Determination of Tannin.]—By E. Johanson.[7458]
[The Incomplete Combustion of Gases.]—By H. B. Dixon.—Abstract of paper read before the British Association at Montreal.[7458]
[Aluminum and its Alloys.][7462]
II.ENGINEERING AND MECHANICS.—[The New Dam at Suresnes.]—With [engraving.][7453]
[Bréarey's Aeronautical Machine.]—With [engraving.][7453]
[Raising of the Fallen Girder of the Douarnenez Viaduct.]—[2 engravings.][7454]
[Improved Wire Testing Machine.]—With [engraving.][7454]
[Improved Doubling and Laying Machine.]—With [engraving.][7454]
[Boiler Tubes.][7455]
[Improved Ladle Carriage.]—[2 figures.][7455]
[The Repair of Boiler Tubes.]—[11 figures.][7455]
[Grulet's Screw for Raising Water.]—[1 engraving.][7456]
III.TECHNOLOGY.—[On Various Toning Baths.]—Several experiments.—By W. M. Ashman.[7456]
[Coating Plates with Gelatine Emulsion.]—[5 figures.][7457]
[Iodo-chloride of Silver Emulsion.]—By V. Schumann.[7458]
[Apparatus for Saturating Water with Sulphurous Acid.]—[1 engraving.][7458]
IV.PHYSICS, ELECTRICITY. ETC.—[The Wave Theory of Light.]—BySir Wm. Thomson.—Sound and light due to wave vibrations.—Differencebetween vibrations of light and sound.—Radiant heat.—Solarspectrum.—Luminiferous ether.—How to measure wavelengths of light and the frequency of vibrations.—With [diagrams.][7448]
[The Limitations of Submarine Telegraphy.][7450]
[Williams' System of Coast Defense by Electrical Torpedoes.]—[Full page of figures.][7451]
[New Electric Gas Lighter.]—[2 figures.][7452]
[Insulators for Telegraph and Telephone Lines.]—[9 figures.][7452]
[Electric Light in Theaters.][7452]
[Rings of Smoke.]—[5 figures.][7461]
V.ARCHITECTURE.—[The New Technical High School of Berlin.]—With [engraving.][7447]
[The New University Buildings at Strassburg.]—[2 engravings.][7447]
VI.BOTANY, ETC.—[An Improved Hyacinth Glass.][7461]
[The Botanical Club of the American Association.][7461]
VII.HYGIENE, MEDICINE, ETC.—[Herbst's Method of Filling.]—Demonstrated by Dr. G. C. CLUDINS.[7459]
[Dr. Koch's Berlin Lecture on Cholera and the Comma Bacillus.][7459]
[Local Anæsthesia by the Hydrochlorate of Cocaine.]—By R. J. Levis, M.D.[7459]
[On Sewage Disposal] [on Land,] by [Chemical Treatment,] and by [Discharge into River or Sea.]—By Prof. H. Robinson.[7460]
VIII.MISCELLANEOUS.—[New York City Street Cars.][7460]
[Petroleum Wells.][7462]

PATENTS.

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A special notice is made in the Scientific American of all Inventions patented through this Agency, with the name and residence of the Patentee. By the immense circulation thus given, public attention is directed to the merits of the new patent, and sales or introduction often easily effected.