Fluxes. This term is applied to substances of easy fusibility, which are added to others more refractory, to promote their fusion. Various fluxes are given in other portions of this work (see Soldering and Enamels), but the principal fluxes are the following :

3461. Black Flux

3461.    Black Flux. Cream of tartar, 2 parts; nitre, 1 part; powder, mix, and deflagrate by small quantities at a time, in a red hot crucible. This is merely carbonate of potash, mixed with charcoal in a finely-divided state. It is used for smelting metallic ores, and exercises a reducing action, as well as promoting the fusion. (See No. 11 (Deflagration).)

3462. White, or Cornish Refining Flux

3462.     White, or Cornish Refining Flux. Cream of tartar and nitre, equal parts; deflagrate as last.

3463. Morveau's Reducing Flux

3463.      Morveau's Reducing Flux. Powdered glass (free from lead), 8 parts; calcined borax and charcoal, each 1 part; all in fine powder, and triturated together thor-oughlv. Used as black flux. (See No. 3461 (Black Flux).)

3464. Flux for Reducing Lead Ore

3464.    Flux for Reducing Lead Ore. Take 6 parts red argol, 4 parts nitre, 2 parts borax, and 1 part fluorspar; pulverize well and mix thoroughly.

3465. Cornish Reducing Flux

3465.    Cornish Reducing Flux. Crude tartar, 10 parts; nitre, 4 parts; borax, 3 parts. Mix as the last.

3466. Crude Flux

3466.    Crude Flux. Same as black flux, (see No. 3461 (Black Flux)), omitting the deflagration. Used for reducing. (See No. 26 (Reduction).)

3467. Liebig's Flux

3467.     Liebig's Flux. Carbonate of soda (dry, see No. 2065 (Colored Fires)), and cyanide of potassium, 1 part each. Used for reducing ar-senious acid.

3468. Fresenius' Flux

3468.    Fresenius' Flux. Carbonate of potassa (dry), (see No. 2065 (Colored Fires)), 3 parts; cyanide of potassium, 1 part. For the arsenical compounds.

3469. Christison's Flux for Arsenic

3469.    Christison's Flux for Arsenic. Carbonate of soda, (crystallized), 8 parts; charcoal (in fine powder), 1 part; mixture is gradually to be heated to redness.

3470. Flux for Copper

3470.    Flux for Copper. Sal-enixum (the refuse from aquafortis), to be obtained at most of the chemical works at a trifling cost, is strongly recommended by Larkin as a general flux for copper foundings, particularly where large masses of copper have to be melted prior to adding the tin and zinc. Nothing is equal to it. This, with charcoal, surpasses everything else.

3471. Various Fluxes

3471.    Various Fluxes. Borax, tartar, nitre, sal-ammoniac, common salt, limestone, glass, fluorspar, resin, and several other substances are used as fluxes in fusing metals, and soldering. On the large scale crude tartar is employed. (See No. 3472.)