Part 266

White marks may sometimes be made on colored papers by the application of acids or alkalies. The result, of course, depends on the nature of the coloring matter in each instance, and any “ink” of this kind would be efficacious or otherwise, according to the coloring present in the paper.

«Yellow Ink.»—I.—Gamboge (in coarse powder), 1 ounce; hot water, 5 ounces. Dissolve, and when cold, add of spirit, 3⁠/⁠4 ounce.

II.—Boil French berries, 1⁠/⁠2 pound, and alum, 1 ounce, in rain water, 1 quart, for 1⁠/⁠2 an hour, or longer, then strain and dissolve in the hot liquor gum arabic, 1 ounce.

«Waterproof Ink» (see also Indelible Inks).—Any ordinary ink may be made waterproof by mixing with it a little ordinary glue. After waterproofing ink in this way it is possible to wash drawings with soap and water, if necessary, without the ink running at all.

«White Stamping Ink.»—

Zinc white 2 drachms White precipitate 5 grains Mucilage 1 drachm Water 6 drachms

Triturate the zinc white with a small quantity of water till quite smooth, then add the mucilage and the remainder of the water.

INK FOR THE LAUNDRY: See Laundry Preparations.

INK FOR LEATHER FINISHERS: See Leather.

INKS FOR TYPEWRITERS: See Typewriter Ribbons.

INK FOR WRITING ON GLASS: See Etching and Glass.

«INLAYING BY ELECTROLYSIS.»

See also Electro-etching, under Etching.

The process consists in engraving the design by means of the sand-blast and stencils on the surface of the article. The design or pattern is rendered conductive and upon this conductive surface a precipitate of gold, silver, platinum, etc., is applied, and fills up the hollows. Subsequently the surface is ground smooth.

«Insect Bites»

«REMEDIES FOR INSECT BITES.»

I.—Carbolic acid 15 grains Glycerine 2 drachms Rose water 4 ounces

II.—Salicylic acid 15 grains Collodion 2 1⁠/⁠2 drachms Spirit of ammonia 5 1⁠/⁠2 drachms

III.—Fluid extract rhus toxicodendron 1 drachm Water 8 ounces

IV.—Ipecac, in powder 1 drachm Alcohol 1 ounce Ether 1 ounce

V.—Betanaphthol 30 grains Camphor 30 grains Lanolin cold cream 1 ounce

VI.—Spirit of sal ammoniac, whose favorable action upon fresh insect bites is universally known, is often unavailable. A simple means to alleviate the pain and swelling due to such bites, when still fresh, is cigar ashes. Place a little ashes upon the part stung, add a drop of water—in case of need beer, wine, or coffee may be used instead—and rub the resulting paste thoroughly into the skin. It is preferable to use fresh ashes of tobacco, because the recent heat offers sufficient guarantee for absolute freedom from impurities. The action of the tobacco ashes is due to the presence of {418} potassium carbonate, which, like spirit of sal ammoniac, deadens the effect of the small quantities of acid (formic acid, etc.) which have been introduced into the small wound by the biting insect.

«Insecticides»

(See also Petroleum.)

«The Use of Hydrocyanic Acid Gas for Exterminating Household Insects.»—Recent successful applications of hydrocyanic acid gas for the extermination of insects infecting greenhouse plants have suggested the use of the same remedy for household pests. It is now an established fact that 1 1⁠/⁠2 grains of 98 per cent pure cyanide of potassium volatilized in a cubic foot of space, will, if allowed to remain for a period of not less than 3 hours, kill all roaches and similar insects.

It may be stated that a dwelling, office, warehouse, or any building may be economically cleared of all pests, provided that the local conditions will permit the use of this gas. It probably would be dangerous to fumigate a building where groceries, dried fruits, meats, or prepared food materials of any kind are stored. Air containing more than 25 per cent of the gas is inflammable; therefore it would be well to put out all fire in an inclosure before fumigating. Hydrocyanic acid, in all its forms, is one of the most violent poisons known, and no neglect should attend its use. There is probably no sure remedy for its effects after it has once entered the blood of any of the higher animals. When cyanide of potassium is being used it should never be allowed to come in contact with the skin, and even a slight odor of the gas should be avoided. Should the operator have any cut or break in the skin of the hands or face it should be carefully covered with court-plaster to prevent the gas coming in contact with the flesh, or a small particle of the solid compound getting into the cut might cause death by poisoning in a few minutes’ time.

Hydrocyanic acid gas should not be used in closely built apartments with single walls between, as more or less of the gas will penetrate a brick wall. An inexperienced person should never use cyanide of potassium for any purpose, and if it be found practicable to treat buildings in general for the extermination of insects, the work should be done only under the direction of competent officials. Experiments have shown that a smaller dose and a shorter period of exposure are required to kill mice than for roaches and household insects generally, and it readily follows that the larger animals and human beings would be more quickly overcome than mice, since a smaller supply of pure air would be required to sustain life in mice, and small openings are more numerous than large ones.

The materials employed and the method of procedure are as follows: After ascertaining the cubic content of the inclosure, provide a glass or stoneware (not metal) vessel of 2 to 4 gallons capacity for each 5,000 cubic feet of space to be fumigated. Distribute the jars according to the space, and run a smooth cord from each jar to a common point near an outside door where they may all be fastened; support the cord above the jar by means of the back of a chair or other convenient object in such a position that when the load of cyanide of potassium is attached it will hang directly over the center of the jar. Next weigh out upon a piece of soft paper about 17 ounces of 98 per cent pure cyanide of potassium, using a large pair of forceps for handling the lumps; wrap up and place in a paper bag and tie to the end of the cord over the jar. After the load for each jar has been similarly provided, it is well to test the working of the cords to see that they do not catch or bind. Then remove the jar a short distance from under the load of cyanide and place in it a little more than a quart of water, to which slowly add 1 1⁠/⁠2 pints of commercial sulphuric acid, stirring freely. The action of the acid will bring the temperature of the combination almost to the boiling point. Replace the jars beneath the bags of cyanide, spreading a large sheet of heavy paper on the floor to catch any acid that may possibly fly over the edge of the jar when the cyanide is dropped, or as a result of the violent chemical action which follows. Close all outside openings and open up the interior of the apartment as much as possible, in order that the full strength of the gas may reach the hiding places of the insects. See that all entrances are locked or guarded on the outside to prevent persons entering; then leave the building, releasing the cords as you go. The gas will all be given off in a few minutes, and should remain in the building at least 3 hours.