Hydrofluoric acid, not electrolysable, 770.
"Experimental Researches in Electricity, Volume 1" by Michael Faraday
The use of hydrofluoric acid, even in small quantities to prevent fermentation, should not be allowed.
"Scientific American Supplement, No. 832, December 12, 1891" by Various
It is sometimes used to detect hydrofluoric acid, which changes its color to yellow.
"A System of Instruction in the Practical Use of the Blowpipe" by Anonymous
The portion insoluble in water is readily dissolved in hydrofluoric acid, and is converted into zircon potassium fluoride.
"Scientific American Supplement, No. 441, June 14, 1884." by Various
With absolutely anhydrous hydrofluoric acid the current will no longer pass.
"Scientific American Supplement, No. 561, October 2, 1886" by Various
Second, hydrofluoric acid will bite its way through glass.
"The Summons" by A.E.W. Mason
It smells somewhat like hypochlorous acid, etches dry glass, and decomposes water, liberating ozone, and forming hydrofluoric acid.
"Scientific American Supplement, No. 633, February 18, 1888" by Various
The preparation of fluorine was finally accomplished by the French chemist Moissan by the electrolysis of hydrofluoric acid.
"An Elementary Study of Chemistry" by William McPherson
For deep etching, hydrofluoric acid is diluted with 11/2 vols.
"Scientific American Supplement, No. 1157, March 5, 1898" by Various
Hydrofluoric acid will not affect a pure diamond, but will dissolve all imitations.
"Practical Mechanics for Boys" by J. S. Zerbe
The emery and excess of hydrofluoric acid may then be thrown into a large beaker of clean water and washed several times.
"On Laboratory Arts" by Richard Threlfall
Electrolysis of a solution in hydrofluoric acid gives cobaltic fluoride, CoF3.
"Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 5" by Various
Hydrofluoric acid is evolved, and the red color of the paper is changed into a straw-yellow.
"The Elements of Blowpipe Analysis" by Frederick Hutton Getman
It is used as a source of hydrofluoric acid, which it evolves when heated with sulphuric acid.
"Encyclopaedia Britannica, 11th Edition, Volume 10, Slice 5" by Various
With ordinary dry-plates the method usually recommended is to immerse them in dilute hydrofluoric acid.
"Photogravure" by Henry R. Blaney
Hydrofluoric acid should be used with great care.
"Scientific American, Vol. XXXIX.--No. 24. [New Series.], December 14, 1878" by Various
The surface of the glass had usually been treated with hydrofluoric acid so as to have a satin-like gloss.
"Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 1" by Various
If possible try fumes of hydrofluoric acid.
"Health, Happiness, and Longevity" by Louis Philippe McCarty
Take a portrait negative that is no longer of any use, and immerse it in a weak solution of hydrofluoric acid.
"Photographic Amusements, Ninth Edition" by Walter E. Woodbury and Frank R. Fraprie
The residue now remaining was filtered and after ignition was treated with hydrofluoric and sulphuric acids.
"Barium, A Cause of the Loco-Weed Disease" by Albert Cornelius Crawford