II.— Blue ointment 1 ounce
Turpentine 3 ounces

Stir well together.

Liquid Bedbug Preparations.
—There is no doubt that the liquid form is the best to use; unlike a powder, or even a paste, it will follow down a crack into remote places where bugs hide, and will prevent their escape, and it will also kill the eggs and nits. The following substances are the most employed, and are probably the best: Kerosene, turpentine, benzine, carbolic acid, corrosive sublimate solution, oil pennyroyal, and strong solution of soap. Here are several good formulas that can be depended upon:
I.— Oil of pennyroyal 1 drachm
Turpentine 8 ounces
Kerosene oil, enough to make 1 gallon.

Put up in 8-ounce bottles as a bedbug exterminator.

II.— Oil of eucalyptus  1 drachm
Eucalyptus leaves  1 ounce
Benzine  2 ounces
Turpentine  2 ounces
Kerosene enough to make 16 ounces.

Mix the turpentine, benzine, and kerosene oil, and macerate the eucalyptus leaves in it for 24 hours; then strain and make up the measure to 1 pint, having first added the oil of eucalyptus.

Fly-killers.

A fly poison that is harmless to man may be made from quassia wood as follows:

Quassia 1,000 parts
Molasses   150 parts
Alcohol    50 parts
Water 5,750 parts

Macerate the quassia in 500 parts of water for 24 hours, boil for half an hour, set aside for 24 hours, then press out the liquid. Mix this with the molasses and evaporate to 200 parts. Add the alcohol and the remaining 750 parts of water, and without filtering, saturate absorbent paper with it.

This being set out on a plate with a little water attracts the flies, which are killed by partaking of the liquid.

Sticky Preparations.—
I.— Rosin 150 parts
Linseed oil  50 parts
Honey  18 parts
Melt the rosin and oil together and stir in the honey.
II.— Rapeseed oil  70 parts
Rosin  30 parts
Mix and melt together.
III.— Rosin  60 parts
Linseed oil  38 parts
Yellow wax   2 parts
IV.— Rosin  10 parts
Turpentine   5 parts
Rapeseed oil   5 parts
Honey   1 part
Sprinkling Powders For Flies.—
I.— Long peppers, powdered  5 parts
Quassia wood, powdered  5 parts
Sugar, powdered 10 parts

Mix, moisten the mixture with 4 parts of alcohol, dry, and again powder. Keep the powder in closely stoppered jars, taking out a sufficient quantity as desired.

II.— Orris root, powdered  4 parts
Starch, powdered 15 parts
Eucalyptol  1 part

Mix. Keep in a closely stoppered jar or box. Strew in places affected by flies.

Fly Essences.—
I.— Eucalyptol  10 parts
Bergamot oil   3 parts
Acetic ether  10 parts
Cologne water  50 parts
Alcohol, 90 per cent 100 parts

Mix. One part of this “essence” is {422} to be added to 10 parts of water and sprayed around the rooms frequently.

II.— Eucalyptol  10 parts
Acetic ether  5 parts
Cologne water 40 parts
Tincture of insect powder (1:5) 50 parts

Remedies Against Human Parasites:

By weight
I.— Yellow wax  85 parts
Spermaceti  60 parts
Sweet oil 500 parts
Melt and add:
Boiling distilled water 150 parts
After cooling add:
Clove oil   2 parts
Thyme oil   3 parts
Eucalyptus oil   4 parts
II.— Bay oil, pressed 100 parts
Acetic ether  12 parts
Clove oil   4 parts
Eucalyptus oil   3 parts
For Head Lice In Children.
—One of the best remedies is a vinegar of sabadilla. This is prepared as follows: Sabadilla seed, 5 parts; alcohol, 5 parts; acetic acid, 9 parts; and water, 36 parts. Macerate for 3 days, express and filter. The directions are: Moisten the scalp and hair thoroughly at bedtime, binding a cloth around the head, and let remain overnight. If there are any sore spots on the scalp, these should be well greased before applying the vinegar.
To Exterminate Mites.
—Mix together 10 parts of naphthalene, 10 parts of phenic acid, 5 parts of camphor, 5 parts of lemon oil, 2 parts of thyme oil, 2 parts of oil of lavender, and 2 parts of the oil of juniper, in 500 parts of pure alcohol.
Vermin Killer.—
Sabadilla, powder  2 av. ounces
Acetic acid    1/2 fluidounce
Wood alcohol  2 fluidounces
Water sufficient to make 16 fluid ounces.

Mix the acetic acid with 14 fluidounces of water and boil the sabadilla in this mixture for 5 to 10 minutes, and when nearly cold add the alcohol, let stand, and decant the clear solution and bottle.

Directions: Shake the bottle and apply to the affected parts night and morning.

Insecticides For Plants.

Two formulas for insecticides with especial reference to vermin which attack plants:

I.— Kerosene 2 gallons
Common soap   1/2 pound
Water 1 gallon

Heat the solution of soap, add it boiling hot to the kerosene and churn until it forms a perfect emulsion. For use upon scale insects it is diluted with 9 parts of water; upon other ordinary insects with 15 parts of water, and upon soft insects, like plant lice, with from 20 to 25 parts of water.

For lice, etc., which attack the roots of vines and trees the following is recommended:

II.— Caustic soda  5 pounds
Rosin 40 pounds
Water, a sufficient quantity.

Dissolve the soda in 4 gallons of water, by the aid of heat, add the rosin and after it is dissolved and while boiling add, slowly, enough water to make 50 gallons. For use, 1 part of this mixture is diluted with 10 parts of water and about 5 gallons of the product poured into a depression near the root of the vine or tree.

For Cochineal Insects.
—An emulsion for fumagine (malady of orange trees caused by the cochineal insect) and other diseases caused by insects is as follows:

Dissolve, hot, 4 parts of black soap in 15 parts of hot water. Let cool to 104° F., and pour in 10 parts of ordinary petroleum, shaking vigorously. Thus an emulsion of café au lait color is obtained, which may be preserved indefinitely. For employment, each part of the emulsion is diluted, according to circumstances, with from 10 to 20 parts of water.

For Locusts.
—Much trouble is experienced in the Transvaal and Natal with locust pests, the remedies used being either a soap spray, containing 1 pound ordinary household soap in 5 gallons of water, or arsenite of soda, the latter being issued by the government for the purpose, and also used for the destruction of prickly pear, and as a basis of tick dips. A solution of 1 pound in 10 gallons of water is employed for full-grown insects, and of 1 pound in 20 gallons of water for newly hatched ones, 1 pound of sugar being added to each pound of arsenite dissolved. The solution sometimes causes sores on the skin, and the natives employed in its use are given grease to rub over themselves as a measure of protection. An advantage of the arsenite solution over soap is that much less liquid need be used.

A composition for the destruction of pear blight, which has been patented in {423} the United States, is as follows: Peppermint oil, 16 parts; ammonia water, 60 parts; calomel, 30 parts; and linseed oil, 1,000 parts.

For Moths And Caterpillars.—
I.— Venice turpentine   200 parts
Rosin 1,000 parts
Turpentine   140 parts
Tar    80 parts
Lard   500 parts
Rape oil   240 parts
Tallow   200 parts
II.— Rosin    50 parts
Lard    40 parts
Stearine oil    40 parts
For Non-masticating Insects.
—For protection against all non-masticating and many mandibulate insects, kerosene oil is much used. It is exhibited in the form of emulsion, which may be made as follows:
Kerosene 2 gallons
Common soap 8 ounces
Water 1 gallon

Dissolve the soap in the water by the aid of heat, bring to the boiling point, and add the kerosene in portions, agitating well after each addition. This is conveniently done by means of the pump to be used for spraying the mixture.

For Scale Insects.
—For destroying scale insects dilute the cochineal emulsion (see above) with 9 times its volume of water; in the case of most others, except lice, dilute with 14 volumes, and for the latter with 20 to 25 volumes.

For the extermination of scale insects, resinous preparations are also employed, which kill by covering them with an impervious coating. Such a wash may be made as follows:

Rosin  3 1/2 pounds
Caustic soda  1 pound
Fish oil  8 ounces
Water 20 gallons

Boil the rosin, soda, and oil with a small portion of the water, adding the remainder as solution is effected.

For the San José scale a stronger preparation is required, the proportion of water being decreased by half, but such a solution is applied only when the tree is dormant.

Scale Insects On Orange Trees.
—Scale insect enemies of orange trees are directly controlled in two ways: (1) By spraying the infested trees with some liquid insecticide, and (2) by subjecting them to the fumes of hydrocyanic acid gas, commonly designated as “gassing.” The latter method is claimed to be the most effective means known of destroying scale insects. In practice the method consists in closing a tree at night with a tent and filling the latter with the poisonous fumes generated by treating refined potassium cyanide (98 per cent) with commercial sulphuric acid (66 per cent) and water. The treatment should continue from 30 to 40 minutes, the longer time being preferable. The work is done at night to avoid the scalding which follows day applications, at least in bright sunshine.

The oily washes are said to be the best for the use by the spraying method. “Kerosene emulsion” is a type of these washes. A formula published by the United States Department of Agriculture follows: Kerosene, 2 gallons; whale-oil soap, 1/2 pound; water, 1 gallon. The soap is dissolved in hot water, the kerosene added, and the whole thoroughly emulsified by means of a power pump until a rather heavy, creamy emulsion is produced. The quantity of soap may be increased if desired. The insecticide is applied by spraying the infected tree with an ordinary force pump with spraying nozzle.

Coating Against The Plant Louse.
—(a)—Mix 75 parts of green soap, 50 parts of linseed oil, and 25 parts of carbolic acid. Afterwards mix the mass with 15,000 parts of water.

(b) Mix 4 parts of carbolic acid with 100 parts water glass.

Louse Washes.—
Unslaked lime 18 parts
Sulphur  9 parts
Salt  6.75 parts

Mix as follows: A fourth part of the lime is slaked and boiled for 2/3 of an hour with the sulphur in 22.6 parts of water. The remainder of the lime is then slaked and added with the salt to the hot mixture. The whole is burned for another half hour or an hour, and then diluted to 353 parts. The fluid is applied lukewarm when the plants are not in active growth.

For Slugs On Roses.—
Powdered pyrethrum  8 ounces
Powdered colocynth  4 ounces
Powdered hellebore 16 ounces
Flea Powder.—
Naphthalene  4 ounces
Talcum 10 ounces
Tobacco dust  2 ounces
{424}
To Keep Flaxseed Free From Bugs.
—As a container use a tin can with a close-fitting top. At the bottom of the can place a small vial of chloroform with a loose-fitting cork stopper. Then pour the flaxseed, whole or ground, into the can, covering the vial. Enough of the chloroform will escape from the vial to kill such insects as infest the flaxseed.

Insect Powders.

Pyrethrum, whale oil (in the form of soap), fish oil (in the form of soap), soft soap, paraffine, Prussic acid, Paris green, white lead, sulphur, carbon bisulphide, acorus calamus, camphor, Cayenne pepper, tobacco, snuff, asafetida, white hellebore, eucalyptol, quassia, borax, acetic ether are most important substances used as insecticides, alone, or in combination of two or more of them. The Prussic acid and Paris green are dangerous poisons and require to be used with extreme care:

Insect powder is used for all small insects and as a destroyer of roaches. The observations of some experimenters seem to show that the poisonous principle of these flowers is non-volatile, but the most favorable conditions under which to use them are in a room tightly closed and well warmed. There may be two poisonous principles, one of which is volatile. Disappointment sometimes arises in their use from getting powder either adulterated, or which has been exposed to the air and consequently lost some of its efficiency.

The dust resulting from the use of insect powder sometimes proves irritating to the mucous membranes of the one applying the powder. This is best avoided by the use of a spray atomizer.

Persistence in the use of any means is an important element in the work of destroying insects. A given poison may be employed and no visible result follow at first, when in reality many may have been destroyed, enough being left to deceive the observer as to numbers. They multiply very rapidly, too, it must be remembered, and vigorous work is required to combat this increase. Where they can easily migrate from one householder’s premises to those of another, as in city “flats,” it requires constant vigilance to keep them down, and entire extermination is scarcely to be expected.

The ordinary insect powder on the market is made from pyrethrum carneum, pyrethrum roseum, and pyrethrum cinerariæ-folium. The first two are generally ground together and are commercially called Persian insect powder; while the third is commonly called Dalmatian insect powder. These powders are sold in the stores under many names and in combination with other powders under proprietary names.

The powder is obtained by crushing the dried flowers of the pellitory (pyrethrum). The leaves, too, are often used. They are cultivated in the Caucasus, whence the specific name Caucasicum sometimes used. Pyrethrum belongs to the natural order compositæ, and is closely allied to the chrysanthemum. The active principle is not a volatile oil, as stated by some writers, but a rosin, which can be dissolved out from the dry flowers by means of ether. The leaves also contain this rosin but in smaller proportions than the flowers. Tincture of pyrethrum is made by infusing the dried flowers in five times their weight of rectified spirit of wine. Diluted with water it is used as a lotion.

Borax powder also makes a very good insectifuge. It appears to be particularly effective against the common or kitchen cockroach. Camphor is sometimes used, and the powdered dried root of acorus calamus, the sweet flag. A mixture of white lead with four times its weight of chalk is also highly recommended. The fish-oil soaps used in a powdered form are made from various recipes; of which the following is a typical example:

Powdered rosin 2 pounds
Caustic soda 8 ounces
Fish or whale oil 4 ounces

Boil together in a gallon of water for at least an hour, replacing some of the water if required.

The following insect-powder formulas are perfectly safe to use. In each instance insect powder relates to either one of the pyrethrum plants powdered, or to a mixture:

I.— Insect powder  8 ounces av.
Powdered borax  8 ounces av.
Oil of pennyroyal  2 fluidrachms
II.— Insect powder  8 ounces av.
Borax  8 ounces av.
Sulphur  4 ounces av.
Oil of eucalyptus  2 fluidrachms
This formula is especially good for cockroaches:
III.— Insect powder 14 ounces av.
Quassia in fine powder  6 ounces av.
White hellebore, powdered  2 ounces av.
{425}
Beetle Powder.—
Cocoa powder  4 ounces
Starch  8 ounces
Borax 37 ounces

Mix thoroughly.

Remedies Against Mosquitoes.
—A remedy to keep off mosquitoes, etc., is composed as follows: Cinnamon oil, 1 part; patchouli oil, 1 part; sandal oil, 4 parts; alcohol, 400 parts. This has a pleasant odor.

Oil of pennyroyal is commonly used to keep mosquitoes away. Some form of petroleum rubbed on the skin is even more efficient, but unpleasant to use, and if left on long enough will burn the skin.

A 40 per cent solution of formaldehyde for mosquito bites gives remarkably quick and good results. It should be applied to the bites as soon as possible with the cork of the bottle, and allowed to dry on. Diluted ammonia is also used to rub on the bites.

Roach Exterminators.
—Borax, starch, and cocoa are said to be the principal ingredients of some of the roach foods on the market. A formula for a poison of this class is as follows:
Borax 37 ounces
Starch  9 ounces
Cocoa  4 ounces
Moth Exterminators.
—Cold storage is the most effective means of avoiding the ravages of moths. Where this is impracticable, as in bureau drawers, camphor balls may be scattered about with satisfactory result. The following is also effective:
Spanish pepper 100 parts
Turpentine oil  50 parts
Camphor  25 parts
Clove oil  10 parts
Alcohol, 96 per cent 900 parts

Cut the Spanish pepper into little bits, and pour over them the alcohol and oil of turpentine. Let stand 2 or 3 days, then decant, and press out. To the liquid thus obtained add the camphor and clove oil, let stand a few days, then filter and fill into suitable bottles. To use, imbibe bits of bibulous paper in the liquid and put them in the folds of clothing to be protected.

Protecting Stuffed Furniture From Moths.
—The stuffing, no matter whether consisting of tow, hair, or fiber, as well as the covering, should be coated with a 10 per cent solution of sulphur in carbon sulphide. The carbon sulphide dissolves the sulphur so as to cause a very fine division and to penetrate the fibers completely.
Powder To Keep Moths Away.—
Cloves 2 ounces
Cinnamon 2 ounces
Mace 2 ounces
Black pepper 2 ounces
Orris root 2 ounces

Powder coarsely and mix well together.

Book-worms.
—When these insects infest books they are most difficult to deal with, as the ordinary destructive agents injuriously affect the paper of the book. The books should be well beaten and exposed to the sun, and a rag moistened with formalin passed through the binding and the covers where possible. In other cases the bottom edge of the binding should be moistened with formalin before putting on the shelves, so that formaldehyde vapor can be diffused.

INSECT TRAP.

Into a china wash-basin, half filled with water, pour a glass of beer; cover the basin with a newspaper, in the center of which a small round hole is cut. Place it so that the edges of the paper lie on the floor and the hole is over the center of the basin. At night beetles and other insects, attracted by the smell of beer, climb the paper and fall through the hole into the liquid.

INSULATION

Electric Insulation:

Insulating Varnishes.
—For earth cables and exposed strong current wires:

I.—Melt 2 parts of asphalt together with 0.4 parts of sulphur, add 5 parts of linseed-oil varnish, linseed oil or cottonseed oil, keep at 320° F. for 6 hours; next pour in oil of turpentine as required.

II.—Maintain 3 parts of elaterite with 2 parts of linseed-oil varnish at 392° F. for 5 to 6 hours; next melt 3 parts of asphalt, pour both substances together, and again maintain the temperature of {426} 392° F. for 3 to 4 hours, and then add 1 part of linseed-oil varnish and oil of turpentine as required.

III.—Insulating Varnish for Dynamos and Conduits with Low Tension.—Shellac, 4 parts; sandarac, 2 parts; linoleic acid, 2 parts; alcohol, 15 parts.

IV.—An insulating material which contains no caoutchouc is made by dissolving natural or coal-tar asphalt in wood oil, adding sulphur and vulcanizing at 572° F. The mixture of asphalt and wood oil may also be vulcanized with chloride of sulphur by the ordinary process used for caoutchouc. Before vulcanizing, a solution of rubber scraps in naphthalene is sometimes added and the naphthalene expelled by a current of steam. Substitutes for hard rubber are made of natural or artificial asphalt combined with heavy oil of tar and talc or infusorial earth.

Most of the insulating materials advertised under alluring names consist of asphalt combined with rosin, tar, and an inert powder such as clay or asbestos. Some contain graphite, which is a good conductor and therefore a very undesirable ingredient in an insulator.

Insulation Against Heat.

An asbestos jacket is the usual insulator for boilers, steampipes, etc. The thicker the covering around the steampipe, the more heat is retained. A chief requirement for such protective mass is that it contains air in fine channels, so that there is no connection with the closed-in air. Most substances suitable for insulating are such that they can only with difficulty be used for a protective mass. The most ordinary way is to mix infusorial earth, kieselguhr, slag-wool, hair, ground cork, etc., with loam or clay, so that this plastic mass may be applied moist on the pipes. In using such substances care should be taken carefully to clean and heat the surfaces to be covered. The mass for the first coating is made into a paste by gradual addition of water and put on thick with a brush. After drying each time a further coating is applied. This is repeated until the desired thickness is reached. The last layer put on is rubbed smooth with the flat hand. Finally, strips of linen are wound around, which is coated with tar or oil paint as a protection against outside injuries. Cork stones consist of crushed cork with a mineral binding agent, and are sold pressed into various shapes.

Leather Waste Insulation.
—Portions of leather, such as the fibers of sole leather of any size and form, are first rendered soft. The surface is then carded or the surface fibers scratched or raised in such a manner that when several pieces are pressed together their surface fibers adhere, and a compact, durable piece of leather is produced. The carding can be done by an ordinary batting machine, the action of which is so regulated that not only are the pieces of leather softened, but the fibers on their surfaces raised. The structure of the separate pieces of leather remains essentially unaltered. The raised fibers give the appearance of a furry substance to the leather. The batted pieces of leather are well mixed with paste or some suitable gum, either in or outside of the machine, and are then put into specially shaped troughs, where they are pressed together into layers of the required size and thickness. The separate pieces of leather adhere and are matted together. An agglutinant, if accessible, will contribute materially to the strength and durability of the product. The layers are dried, rolled, and are then ready for use. The pieces need not be packed together promiscuously. If larger portions of waste can be secured, the separate pieces can be arranged one upon another in rows. The larger pieces can also be used for the top and bottom of a leather pad, the middle portion of which consists of smaller pieces.

Insulation Against Moisture, Weather, Etc.

Experiments have shown that with the aid of red lead a very serviceable, resistive, and weatherproof insulation material may be produced from inferior fibers, to take the place, in many cases, of gutta-percha and other substances employed for insulating purposes, and particularly to effect the permanent insulation of aerial conductors exposed to the action of the weather. Hackethal used for the purpose any vegetable fiber which is wrapped around the conductors to be insulated. The fiber is then saturated with liquid red lead. The latter is accomplished in the proportion of 4 to 5 parts of red lead, by weight, to 1 part, by weight, of linseed oil, by the hot or cold process, by mere immersion or under pressure. All the three substances, fiber, oil, and red lead, possess in themselves a certain insulating capacity, but none of them is alone of utility for such purposes. Even the red lead mixed with linseed oil does not possess in the liquid state a high degree of insulating power. {427} Only when both substances, the ingredients of the linseed oil capable of absorbing oxygen and the lead oxide rich in oxygen, oxidize in the air, a new gummy product of great insulating capacity results.

IODINE SOLVENT.

Iodine is quickly dissolved in oils by first rubbing up the iodine with one-fourth of its weight of potassium iodide and a few drops of glycerine, then adding a little oil and rubbing up again. The addition of the resultant liquid to the rest of the oil and a sharp agitation finishes the process.

IODOFORM DEODORIZER.

Rub the part with about a teaspoonful of wine vinegar, after a previous thorough washing with soap.

IRON

(See also Metals and Steel.)

To Color Iron Blue.

—One hundred and forty parts of hyposulphite of soda are dissolved in 1,000 parts of water; 35 parts of acetate of lead are dissolved in 1,000 parts of water; the two solutions are mixed, boiled, and the iron is immersed therein. The metal takes a blue color, such as is obtained by heating.

To Distinguish Iron From Steel.

—The piece of metal to be tested is washed and then plunged into a solution of bichromate of potash, with the addition of considerable sulphuric acid. In half a minute or a minute the metal can be taken out, washed, and wiped. Soft steels and cast iron assume under this treatment an ash-gray tint. Tempered steels become almost black, without any metallic reflection. Puddled and refined irons remain nearly white and always have metallic reflections on the part of their surface previously filed, the remainder of the surface presenting irregular blackish spots.

Another method is to apply a magnet. Steel responds much more quickly and actively to the magnetic influence than does iron.

Powder For Hardening Iron And Steel.

—For wrought iron place in the charge 20 parts, by weight, of common salt; 2 parts, by weight, of potassium cyanide; 0.3 parts, by weight, of potassium bichromate; 0.15 parts, by weight, of broken glass; and 0.1 part, by weight, of potassium nitrate for case-hardening. For cooling and hardening cast iron: To 60 parts, by weight, of water add 2.5 parts, by weight, of vinegar; 3 parts, by weight, of common salt; and 0.25 parts, by weight, of hydrochloric acid.

Preventing The Peeling Of Coatings For Iron.

—To obviate the scaling of coatings on iron, if exposed to the attacks of the weather, it is advisable to wash the iron thoroughly and to paint it next with a layer of boiling linseed oil. If thus treated, the paint never cracks off. If the iron objects are small and can be heated, it is advantageous to heat them previously and to dip them into linseed oil. The boiling oil enters all the pores of the metal and drives out the moisture. The coating adheres so firmly that frost, rain, nor wind can injure it.

To Soften Iron Castings.

—To soften hard iron castings, heat the object to a high temperature, cover it over with fine coal dust or some similar substance, and allow it to cool gradually. When the articles are of small size, a number of them are packed in a crucible with substances yielding carbon to iron at a glowing heat. The crucible is then tightly closed, and placed in a stove or on an open fire. It is gradually heated and kept at a red heat for several hours, and then allowed to cool slowly. Cast-iron turnings, carbonate of soda, and unrefined sugar are recommended as substances suitable for packing in the crucible with the castings. If unrefined sugar alone is added, the quantity must not be too small. By this process the iron may be rendered extremely soft.

To Whiten Iron.

—Mix ammoniacal salt in powder with an equal volume of mercury. This is dissolved in cold water and mixed thoroughly. Immerse the metal, heated to redness, in this bath and it will come out possessing the whiteness and beauty of silver. Care should be taken not to overheat the article and thus burn it.

IVORY

(See also Bones, Shell, and Horn.)

To Color Ivory:

Red.—The article is placed for 24 hours in water, 1,000 parts of which carry 100 parts of vinegar (acetic acid, 6 per cent), and from 1 to 5 parts of aniline red. As soon as it acquires the desired color pour off the liquid, let the ivory dry, and polish with Vienna lime.

Black.—Wash the article first in potash or soda lye and then put into a neutral solution of silver nitrate. Drain off the liquid and lay in the direct sunshine.

Red-Purple.—Put the article in a weak solution of triple gold chloride and then into direct sunshine.

Red.—For a different shade of red (from the first given), place the article for a short time in water weakly acidified with nitric acid and then in a solution of cochineal in ammonia.

Yellow.—Leave for several hours in a solution of lead acetate, rinse and dry. When quite dry place in a solution of potassium chromate.

To Color Billiard Balls Red.—

Fiery Red.—Wash the article first in a solution of carbonate of soda, then plunge for a few seconds in a bath of equal parts of water and nitric acid. Remove, rinse in running water; then put in an alcoholic solution of fuchsine and let it remain until it is the required color.

Cherry Red.—Clean by washing in the sodium carbonate solution, rinse and lay in a 2 per cent solution of tin chloride, for a few moments, then boil in a solution of logwood. Finally lay in a solution of potassium carbonate until it assumes the desired color.

Pale Red.—Wash in soda solution, rinse and lay for 25 minutes in a 5 per cent solution of nitric acid, rinse, then lay for several minutes in a weak solution of tin chloride. Finally boil in the following solution: Carmine, 2 parts; sodium carbonate, 12 parts; water, 200 parts; acetic acid enough to saturate.

Brown.—Apply several coats of an ammoniacal solution of potassium permanganate. Similar results are obtained if the solution is diluted with vinegar, and the ivory article allowed to remain in the liquid for some time.

Etching On Ivory

(see also Etching).—Although decorations on ivory articles, such as umbrella handles, cuff-buttons, fans, book-covers, boxes, etc., are generally engraved, the work is frequently done by etching. The patterns must be very delicate, and are executed in lines only. The simplest way is to cover the surface with a thin rosin varnish. Then transfer the pattern and scratch it out accurately with a pointed needle. Otherwise proceed same as in etching on metal and stone, making an edge of modeling wax around the surface to be etched and pouring on the acid, which consists, in this case, of sulphuric acid, 1 part, to which 5 to 6 parts of water are added. It acts very quickly. The lines turn a deep black. If brown lines are desired, dissolve 1 part of silver nitrate in 5 parts of water, etch for a short time, and expose the article for a few hours to the light, until the design turns brown. Very often etchings in ivory are gilded. For this purpose, fill the etched patterns accurately with siccatives, using a writing pen, dry, and dab on gold leaf. After a few hours remove the superfluous gold with wadding, and the design will be nicely gilded. Etched ivory articles present a very handsome appearance if they are first covered with a silvery gloss, the design being gilded afterwards. For the former purpose the etched object is laid in the above described solution of silver nitrate until it has acquired a dark yellow color. Then rinse it off in clean water and, while still moist, expose to direct sunlight. After 3 to 4 hours the surface becomes entirely black, but will take on a fine silvery luster if rubbed with soft leather.