of iron; turns BLUE when moistened with a weak solution of prussiate of potassa, and BLACK when moistened with infusion of galls.—5. The diluted solutions of nitrate of silver and of terchloride of gold; become respectively DARK BROWN and PURPLE when exposed to the sunlight.—6. Aqua fortis, spirits of salts, oil of vitriol, common salt, or saltpetre, dissolved in a large quantity of water; turns YELLOW or BROWN when heated.—7. Solution of chloride or nitromuriate of cobalt; turns GREEN when heated, and disappears again on cooling. If the salt is pure, the marks turn BLUE.—8. Solution of acetate of cobalt, to which a little nitre has been added; becomes ROSE COLOURED when heated, and disappears on cooling.—9. A weak solution of the mixed chlorides of cobalt and nickel; turns GREEN. The last three are about the best of our sympathetic inks.—10. Solution of acetate of lead; turns BROWNISH-BLACK when exposed to the fumes of sulphuretted hydrogen.—11. A weak solution of nitrate of mercury; turned BLACK by heat and sulphuretted fumes.—12. Rice water or decoction of starch; turned BLUE by a solution of iodine in weak spirit, and by the fumes of iodine, if the paper is first slightly moistened by exposure to steam or damp air.

Ink, Vi′olet. The same as PURPLE INK, but weaker.

Ink, Yel′low. 1. From gamboge (in coarse powder), 1 oz.; hot water, 5 oz.; dissolve, and when cold, add of spirit, ³⁄₄ oz.

2. Boil French berries, ¹⁄₂ lb., and alum, 1 oz., in rain water, 1 quart, for half an hour, or longer, then strain and dissolve in the hot liquor gum Arabic, 1 oz.

Ink, Zinc Labels, to write on. Syn. Horticultural ink. 1. Dissolve 100 gr. of tetrachloride of platinum in a pint of water. A little mucilage and lamp black may be added.

2. Sal ammoniac 1 dr.; verdigris, 1 dr.; lampblack, ¹⁄₂ dr.; water, 10 dr.; mix.

INK POW′DERS. Prep. 1. Aleppo galls, 4 oz.; sulphate of iron, 1¹⁄₂ oz.; gum Arabic, 1 oz.; lump sugar, ³⁄₄ oz.; (all quite dry and in powder); mix, and divide into 3 packets. A pint of boiling water poured over one of them produces, in a few hours, a pint of excellent ink.

2. Aleppo galls, 3 lbs.; copperas, 1 lb.; gum Arabic, ¹⁄₂ lb.; white sugar, ¹⁄₄ lb.; all in powder; mix, and divide into two-ounce packets, to be used as the last. Ink powders are very useful in travelling.

INK STAINS, to remove. See Spots.

INOCULA′TION. Syn. Inoculatio, L. In medicine and surgery, the application of poisonous

or infectious matter to any part of the body for the purpose of propagating a milder form of disease, and thus preventing or lessening the virulence of future attacks. In this country the term is generally restricted to the artificial propagation of smallpox. See Vaccination.

INOSIN′IC ACID. An acid said by Liebig to exist in the juice of the flesh of animals, after it has deposited its kreatine.

IN′OSITE. A species of unfermentable sugar, discovered by Scherer in the juice of flesh. It forms beautiful crystals.

IN′SECTS. Syn. Insecta, L. A class of invertebrate animals belonging to the subkingdom Annuloso. The true insect is defined as an articulated animal, having six legs, 2 antennæ, 2 compound eyes; a small brain at the anterior extremity of a double medullary cord; its circulation is effected by a pulsating dorsal vessel, provided with numerous valves; its respiration by tracheæ, which form 2 lateral trunks, and ramify through the body. The generation of insects is oviparous. There are two distinct sexes. The adult state is attained through a series of metamorphoses. In general, every insect possesses 2 pairs of wings; the trunk in the adult animal is usually composed of 3 chief parts—the head, thorax, and abdomen. The trunk of an insect may also be described as consisting of 13 segments, of which 1 constitutes the head, 3 constitute the thorax, and 9 the abdomen. Insects are arranged in the following orders:—1. Hymenoptera, including bees, wasps, ichneumon-flies, &c.—2. Coleoptera, including all those kinds commonly called beetles.—3. Neuroptera, dragon-flies, ephemeræ, white ants, &c.—4. Strepsiptera, the stylops, &c.—5. Lepidoptera, the butterflies and moths.—6. Diptera, the house-fly and other 2-winged insects.—7. Orthoptera, crickets, grasshoppers, locusts, earwigs, &c.—8. Hemiptera, bugs, frog-hoppers, aphides, &c.—9. Aptera, fleas, &c. There are several animals belonging to the classes MYRIOPODA and ARACHNIDA which are commonly but erroneously called ‘insects.’ Of these the centipedes, spiders, and acarides, or mites, are well-known examples. Several useful products, as SILK, WAX, HONEY, COCHINEAL, LAC, CANTHARIDES, &c., are supplied by insects. The class includes numerous creatures which are extremely destructive, and others which are regarded as domestic pests. In the articles devoted to these offensive insects various methods of exterminating them are noticed. A powder for destroying insects has recently been introduced into this country, and has been found peculiarly efficacious. This powder, which is known under various names (INSECTS-DESTROYING POWDER, DUMONT’S INSECTICIDE, &c.), is produced by the Pyrethrum roseum Caucasicum, a composite flower growing wild in the Caucasus. The central or tubular florets of the disc are alone employed, and when ground, furnish the

powder of commerce. This powder, though so destructive to insect life, has no injurious effect upon man or domestic animals. See Acari, Ant, Bee, Bug, Bites and Stings, Cantharides, Cochineal, Lac, Pediculi, Silk, &c.

INSECT′ICIDE POWDER. See Insects.

INTEM′PERANCE. Under this head we refer to habitual indulgence in the use of spirituous or fermented liquors, whether accompanied or not by fits of intoxication or drunkenness.

The pernicious influence of intoxicating liquors upon individuals and upon society has been so often and ably exposed by the clergy, judges, and magistrates, and by philanthropists of every kind, that it would be folly to do more than refer to it here. Fully one half of the dark or disreputable deeds of those who fill our gaols, and fully an equal proportion of the poverty and wretchedness which pauperises our population and crowds our workhouses, are traceable to this damning vice of the Anglo-Saxon race—intemperance.

To cure HABITUAL DRUNKENNESS various means have been proposed, most of which are more ingenious than useful. The following, however, deserves respectful notice:—

Dr Kain, an