2529. Indestructible "Writing Ink

2529.     Indestructible "Writing Ink. Shellac, 4 parts; borax, 2 parts; sort water, 36 parts; boil in a close vessel till dissolved; then filter, and take of gum-arabic, 2 parts; soft water, 4 parts. Dissolve, and mix the two solutions together, and boil for 5 minutes as before, occasionally stirring to promote their union; when cold, add a sufficient quantity of finely powdered indigo and lampblack to color; lastly, let it stand for 2 or 3 hours, until the coarser powder has subsided, and bottle for use. Use this fluid with a clean pen, and keep it in glass or earthen inkstands, as many substances will decompose it while in the liquid state. When dry it will resist the action of water, oil, turpentine, alcohol, diluted sulphuric acid, diluted hydrochloric acid, oxalic acid, chlorine, and the caustic alkalies and alkaline earths.

2530. Simple Carbon Ink

2530.    Simple Carbon Ink. Dissolve 30 grains of sugar in 30 grains of water, to which add a few drops of concentrated sulphuric acid. Upon heating this mixture the sugar becomes carbonized by the acid, and when applied to the paper it leaves a coating of carbon which cannot be washed off. This stain is rendered more perfect by the decomposing action of the ink itself upon the paper, and thus resists the action of chemical agents.

2531. Drawing Ink

2531.     Drawing Ink. A very black and indelible drawing ink may be made by dissolving shellac in a hot water solution of borax, and rubbing up in this solution a fine quality of Indian ink. After using, dip the drawing pen in alcohol, and wipe dry to keep it clean and bright. (See No. 2514 (Carbon Ink).)

2532. Permanent Ink for Use with Stamps or Type

2532.     Permanent Ink for Use with Stamps or Type. Mix equal parts black oxide of manganese and hydrate of potash, heat to redness, and rub with an equal quantity of smooth white clay into a paste, water being added for the purpose. Or: Sulphate of manganese, 2 drachms; lampblack, 1 drachm; powdered loaf sugar, 4 drachms ; rubbed into paste with water. After stamping, dry the linen and wash well in water.

2533. Sympathetic, or Invisible Inks, for Secret Writing

2533.   Sympathetic, or Invisible Inks, for Secret Writing. These are colorless inks which require the aid of heat or some other agency to develop the characters written with them. Their use has been rendered specially practical since the recent introduction of the postal correspondence cards in England and elsewhere. By previous arrangement between correspondents, the receiver of a card only needs some visible sign on the card to identify the writer or sender; this will at once suggest the means to be employed to develop the particular ink the receiver's correspondent has agreed to use.

2534. Black Sympathetic Inks

2534. Black Sympathetic Inks.

"Writing with a solution of sugar of lead will be turned black by moistening the paper with sulphide of potassium.

If nitrate of silver be used, the writing will become black by dipping the paper in a solution of ammonia.

Chloride of mercury will turn black when wetted with chloride of tin.

A weak infusion of galls is turned black by sulphate of iron (copperas).

Reversing the above, writing with copperas turns black by moistening with infusion of galls.