Silvering Solution for Electrotype Plates.—Nitrate of silver 2 drachms, distilled water 37 drachms. Dissolve and add sal ammoniac 1 drachm, hypophosphate of soda 4 drachms, precipitated chalk 4 drachms. Agitate the preparation occasionally for twelve hours, when it will be ready for use. Apply with a piece of fine sponge.
How to coat Electrotypes with Silver.—Electrotypes can be coated with silver (for working with red ink) in the following manner: One part copper, 5 parts pure tin; this alloy to be granulated, not too fine, and mixed with water and cream of tartar into a paste. To each 200 parts of the granulated alloy add 1 part oxide silver, the electro is then laid in it, and boiled for a short time, when it will be found to be beautifully plated. Fresh oxide must be added from time to time. This coating is quite equal in durability to silver or tin.
To soften Leather Belting.—Castor oil is a good article for keeping leather belting soft and pliable.
How to open a Ball of Twine.—A ball of twine, if opened from the inside, will run off easily enough and give no trouble in the untwining; but if begun from the outside, it will speedily get tangled and knotted.
To prevent Adhesion.—M. Garde, in l’Imprimerie, tells paper-makers how to obviate the inconvenience of the adhesion together of sized papers, on damping, by the coagulation of the size. This is effected in the mills, by dipping the sheets in a solution of alum or tannin. A secondary advantage obtained is that the paper becomes tougher.