15. (Crimson Marking Ink.) Dissolve 1 oz. of nitrate of silver, and 1-1/2 oz. of carbonate of soda in crystals, separately in distilled water, mix the solutions, collect and wash the precipitate on a filter, introduce the washed precipitate still moist into a Wedgwood mortar, and add to it tartaric acid 2 dr. and 40 gr., rubbing together till effervescence has ceased; dissolve carmine 6 grains, in liquor ammoniæ (·882) 6 oz., and add to it the tartrate of silver, then mix in white sugar, 6 dr., and powdered gum Arabic, 10 dr., and add as much distilled water as will make 6 oz. (‘Pharm. Journal.’)

Obs. The products of the first two of the above formulæ constitute the marking ink of the shops. They have, however, no claim to the title of ‘INDELIBLE INK,’ “which no art can extract without injuring the fabric”——as is generally represented. On the contrary, they may be discharged with almost as much facility as common iron-moulds. This may be easily and cheaply effected by means of ammonia, cyanide of potassium, the chlorides of lime and soda, and some of the hyposulphites, without in the least injuring the texture of the fabric to which they may be applied. The only precaution required is that of rinsing the part in clean water immediately after the operation. The ‘marking ink without preparation’ is more easily extracted than that ‘with preparation.’ The former has also the disadvantage of not keeping so well as the latter, and of depositing a portion of fulminating silver, under some circumstances, which renders its use dangerous. The thinner inks, when intended to be used with type or plates, are thickened by adding a little more gum, or some sugar.

=Ink, Mark′ing.= Syn. PACKER’S INK. Ink bottoms. Used by packers for marking bales, boxes, &c.

=Ink, Perpet′ual.= Prep. 1. Pitch, 3 lbs.; melt over the fire, and add of lampblack, 3/4 lb.; mix well.

2. Trinidad asphaltum and oil of turpentine, equal parts. Used in a melted state to fill in the letters on tombstones, marbles, &c. Without actual violence, it will endure as long as the stone itself.

=Ink, Print′er’s.= See PRINTING INK.

=Ink, Pur′ple.= 1. A strong decoction of logwood, to which a little alum or chloride of tin has been added.

2. (Normandy.) To 12 lbs. of Campeachy wood add as many gallons of boiling water, pour the solution through a funnel with a strainer made of coarse flannel, or 1 lb. of hydrate, or acetate of deutoxide of copper finely powdered (having at the bottom of the funnel a piece of sponge); then add immediately 14 lbs. of alum, and for every 340 galls. of liquid add 80 lbs. of gum Arabic or gum Senegal. Let these remain for three or four days and a beautiful purple colour will be produced.

=Ink, Red.= Prep. 1. Brazil wood (ground), 4 oz.; white-wine vinegar (hot), 1-1/4 pint; digest in glass or a well-tinned copper or enamel saucepan, until the next day, then gently simmer for half an hour, adding towards the end gum Arabic and alum, of each 1/2 oz.

2. Ground Brazil wood, 10 oz.; white vinegar, 10 pints; macerate for 4 or 5 days; then boil as before to one half, and add of roach alum, 4-1/2 oz.; gum, 5 oz.; and when dissolved, bottle for use.

3. As the last, but using water or beer instead of vinegar.

4. Cochineal (in powder), 1 oz.; hot water, 1/2 pint; digest, and when quite cold, add of spirit of hartshorn, 1/4 pint (or liquor of ammonia, 1 oz., diluted with 3 or 4 oz. of water); macerate for a few days longer, and then decant the clear. Very fine.

5. (Buchner.) Pure carmine, 20 gr.; liquor of ammonia, 3 fl. oz.; dissolve, then add of powdered gum, 18 gr. Half a drachm of powdered drop lake may be substituted for the carmine where expense is an object. Colour superb.

6. (Henzeler.) Brazil wood, 2 oz.; alum and cream of tartar, of each 1/2 oz.; rain water, 16 fl. oz.; boil to one half, strain, add of gum (dissolved), 1/2 oz.; and when cold, further add a tincture made by digesting powdered cochineal, 1-1/2 dr., in rectified spirit, 1-1/2 fl. oz.

7. (Redwood.) Garancine and liquor of ammonia, of each 1 oz.; distilled water (cold), 1 pint; triturate together in a mortar, filter, and dissolve in the solution, gum Arabic 1/2 oz.

=Ink, Se′pia.= See SEPIA.

=Ink, Sil′ver.= From silver leaf or powdered silver, as GOLD INK.

=Ink, Sympathet′ic.= Syn. DIPLOMATIC INK, INVISIBLE I. Fluids which, when used for writing, remain invisible until the paper is heated, or acted on by some other chemical agent. Sympathetic inks have been frequently employed as the instruments of secret correspondence, and have often escaped detection; but by heating the paper before the fire until it begins to grow discoloured by the heat, the whole of them may be rendered visible.

The following are the most common and amusing sympathetic inks:——1. Sulphate of copper and sal ammoniac, equal parts, dissolved in water; writes colourless, but turns YELLOW when heated.——2. Onion juice; like the last.——3. A weak infusion of galls; turns BLACK when moistened with weak copperas water:——4. A weak solution of sulphate 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, 1-1/2 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.