MAGAZINE, $4.00 A YEAR WEEKLY, $4.00 A YEAR BAZAR, $4.00 A YEAR ROUND TABLE, $2.00 A YEAR [Illustration: THOMPSON'S EYE WATER] [Illustration: THE CAMERA CLUB] Any questions in regard to photograph matters will be willingly answered by the Editor of this column, and we should be glad to hear from any of our club who can make helpful suggestions. HOW TO PREPARE GOLD FOR USE IN PHOTOGRAPHY. Several queries have been sent to the editor recently asking how to prepare gold for photographic use. Gold is one of the chemical elements. Its symbol is "Au," the first two letters of the word aurum, the Latin name for gold. Gold is used in photography in the form of chloride of gold. To make chloride of gold, pure gold is dissolved in a mixture of nitric and hydrochloric (muriatic) acid. This mixture is called "aqua-regia," from its being the only known solvent of gold. It is made by mixing one part of nitric acid, two parts of muriatic acid, and three parts of water. Gold dissolves very readily in this mixture. Chloride of gold may be made from gold-leaf (such as is used by dentists), gold coins, scraps of gold ornaments, etc. Where the amateur prepares his own gold about half the expense is saved. Put the gold into a glass vessel and pour over it eight times its weight of aqua-regia. Set the vessel in a dish of hot water, and let it stand on the back of the stove till the gold is entirely dissolved. Pour the solution into a porcelain crucible, and subject to heat till all the free acid is evaporated or driven off. After the acid is evaporated, add three or four drachms of distilled water and evaporate again. When the water is evaporated, enough distilled water must be added to make the solution up to a standard strength--one grain of gold to three drachms of water. If twenty-four grains of pure gold are used, add nine ounces of distilled water. Keep this solution in a dark place or in an opaque bottle. The bottle may be wrapped in black needle-paper, which will also protect it from the light. Gold coins and jewelry contain more or less alloy, but this does not seem to affect the print in any way. One grain of gold will tone from twenty to twenty-five cabinet prints. The chemical formula for chloride of gold is AuCl_{3}, meaning that a molecule of chloride of gold contains one atom of gold and three atoms of chlorine. In order to preserve the gold chloride longer, it is usually prepared with salt, and is called chloride of gold and sodium. It is in this form that it is sold for use in photographic work, the pure chloride of gold attracting and absorbing moisture from the air.