Secrets of Wise Men, Chemists and Great Physicians

Part I.--Miscellaneous.

Gelatine Copying Pad.

By this process a letter, postal card, drawing, or other manuscript can be duplicated from sixty to one hundred times from one original. Reproductions from the copying pad are now admitted in the mails as third-class matter, i. e., one cent for every two ounces or fraction thereof. A soft, gelatinous composition, similar to that used in making printers’ rollers, is made and poured into shallow pans of the required size. The pans should be made of stout zinc one-half inch deep on the inside, with a lid or cover. The length and breadth of the pans is determined by the class of copying to be done. Always make the pan slightly larger than the paper used. The three sizes given below will answer most purposes:

Postal card size 4×6 inches. Note paper size 6-1/2×10 inches. Full letter size 9×12 inches.

The composition is made as follows:

Good glue 4 ounces av. Glycerine 16 ounces av. Water 8 fluid ounces.

Break up the glue and soak in the water for a few hours, then heat by water-bath until melted. Next add the glycerine and heat together for some time to evaporate part of the water, and then strain into the pan, which should be placed perfectly level and filled about two-thirds full; skim with a card to free from bubbles, and set away to cool. An improvement consists in adding one ounce of carbonate of barium to the fluid while warm. The composition should be made somewhat softer for winter use than for summer, which can be done by adding a little larger proportion of glycerine. Another way to make the composition is to soak over night in cold water best gelatine or glue 1 part, and the excess of water poured off. The glue is then warmed in a water-bath with the addition of from 10 to 12 parts of glycerine, to which may be added 4 to 6 parts of finely ground heavy spar, and one part dextrine thoroughly mixed by constant stirring. (In summer less glycerine.)

The letter or sketch to be duplicated is written on a sheet of paper with ink specially prepared for the purpose (see inks). For the original it is best to use smooth, well-sized writing paper, allowing the ink to dry without using a blotter. After writing the original place it face downward on the pad, and rub it gently with the hand to insure contact at every point. Let it remain from two to six minutes, according to the number of copies you wish to print. In cold weather it should be left longer, as it requires more time for the composition to absorb the ink. Remove the original carefully, and a reversed impression will be observed on the pad. To take off copies lay dry sheets of paper on the reversed impression, press gently, and remove quickly.

When you have taken all the copies you require wash the ink from the surface at once with a sponge and plenty of lukewarm water; never use hot water. The surface of the composition will allow considerable rubbing without fear of tearing it, if not done roughly and carelessly. Be sure your sponge is free from sand and grit, and also avoid scratching with the finger nails. Always wash the surface with a sponge before using, and dry with a newspaper. In cold weather if the composition feels chilled it will not absorb the ink properly, and the copies will be faint unless it be carefully warmed to a moderate temperature. Attention to these details will produce the most gratifying results.

Foliotypes.

Horace M. Engle, Esq., of Marietta, Pa., has devised a method of taking leaf-prints of marked beauty, which he terms “foliotypes,” some specimens of which he sent to Dr. Gray, the eminent botanist, who pronounced the process a new way, and advised him to send an account of it to the Botanical Gazette, which he generously did. We have employed the method according to the explanation there given (which we reprint in full) with the most delightful results, having secured prints of some beautiful leaves which are faithful to nature in color and outline, with all their delicate tracery: “The method is of actual usefulness to the botanist, as well as a refining recreation for others who love Nature ‘on general principles.’ For illustrating monographs and similar papers, where the number is too limited to warrant an expensive lithograph; for identifying a rare specimen, or as an adjunct to an herbarium, combining portability, unalterability, and beauty withal the method seems particularly fitted. But aside from this others may find a delightful and instructive recreation in taking prints of the entire flora of the old farm, the trees of a certain grove, the native annuals of a county, the ferns of a State, or any other special field that seems most inviting. Such copies may be taken in a blank book suited to the purpose, or, better, take them on single sheets of uniform size, as in this way imperfect copies may be thrown out, and when the work is completed they may be named, classified, and bound, making a volume of real value and worthy of just pride.

“The process consists in using the leaf for producing an impression as a printer uses type, the ink being green, and the pressure applied either by hand or with a press. There will be needed for the work (1) a small ink roller such as printers use for inking type by hand in taking proofs; (2) a stout window glass (10×12 is a good size) fastened securely (not glued, as it may warp and break,) to an evenly planed board about twice its surface, say 10×24. A small quantity of the ink is put on the glass and spread with a knife, after which it is distributed evenly by going over in all directions with the ink roller. When this has been carefully done the leaf to be copied is laid on a piece of waste paper and inked by applying the roller once or more with moderate pressure. This leaves a film of ink on the veins and network of the leaf, which should then be placed on a piece of blank paper and considerable pressure applied for a few moments. When the leaf is removed from the paper the work is done.

“To get the best results several points must be carefully noted. Get a quarter or half a pound of dark green ink, which is put up in collapsible tubes costing from fifty cents to $2 per pound, according to quality. As sold it is invariably too thick for this purpose, and should be thinned by adding several drops of balsam of copaiba to as much ink as may be taken on a salt spoon. Much depends on the proper consistency of the ink. In inking the leaf is liable to curl on the roller, but it should part readily from it. In case it sticks tightly the ink is too thick. Take care that the ink is evenly distributed on the glass and roller, as it is essential that each part of the leaf receives an equal coating of ink. If the leaf is large ink it part by part, keeping the roller well supplied. A roller three inches long, costing forty cents, will answer for all small leaves and branches of plants. Clean the roller and glass with benzine after using. If the leaf is finely veined the lower surface makes the better print, but if the veins are coarse and large the upper surface may be used. If the specimen is fleshy or brittle allow it to wilt until it becomes more pliable, or if necessary it may be pressed and dried first. In most cases the best copy is obtained after taking one or two impressions, as the leaf takes the ink better after several applications. A good quality of unsized paper that is made slightly damp by placing between sheets of moist newspaper is best for general work, but in other cases well sized paper will take a copy that will allow a foliotype (may I coin the word?) to bear inspection side by side with a good lithograph. I find a copying press very valuable in making the impression, especially if the leaf is at all coriaceous. If it be soft it should be covered with a few thicknesses of newspaper. If it is irregular in thickness, paper may be laid over the thin parts, so that equal pressure is received. This is necessary with all leaves that have thick stems. If the branch is very irregular or delicate, or in the absence of a press of any kind, the specimen may be covered with several layers of paper, and held in place by one hand while the pressure is applied by the thumb or palm of the other hand as required.

“These particulars are as complete as practicable. Experiments will lead to many improvements in details. Employ tact and neatness, and you will be surprised at the result.”

Continue reading Secrets of Wise Men, Chemists and Great Physicians free in the Wunder reader →