This word is applied to whatever is subjected to calcination, or change from burning. It chiefly refers to metals after having sustained the action of fire; and to calcareous earths, which are burnt to lime. See Calcinatio.

Lime stone, also called saxum calcarium, abesum, algeria, is a general name for all those stones from which quick lime is commonly prepared. Though the limes prepared from different stones answer many general purposes equally well, they differ greatly in their efficacy in medicine, and in many chemical and other experiments.

When stones of the calcareous kind have been calcined by the fire, they are converted into quick lime, called calx viva, and in some obsolete authors, anora, gir, nix fumans, and almyzinthra.

Quick lime dissolves in nitrous, marine, and vegetable acids; unites with the vitriolic into selenite, an earthy salt, scarcely soluble and insipid; produces heat on mixing with water, imparting to it a medicinal quality. If quick lime is exposed to the atmosphere, it falls into a powder, and loses all its distinguishing properties except that it retains its acrimony longer in a moist than in a dry state.

The stones from which quick lime is produced contain a large quantity of air, which, in calcination, is expelled: hence strong quick lime raises no effervescence, and emits no air bubbles during its dissolution in acids.

Calx viva,or quick lime, is lime in its most caustic state, with the air wholly separated. When styled extincta it has been long exposed, and fallen to powder. When deprived of its acrimony by repeated affusions of water, it is called washed lime.

Calcareous earth is commonly found saturated with aerial acid, which exhibits the appearance of effervescence upon being driven from its basis by a stronger acid. It is found dissolved in most waters by means of a redundant portion of this acid, which by burning is lost, together with a proportion of water with which it was combined. It also absorbs a considerable proportion of caloric, which on slaking is let loose.

Quick lime is employed for increasing the activity of alkaline salts, for making the milder kinds of caustics, and for destroying the hair on places where it is thought to be unseemly; it dissolves sulphurs and vegetable resins, and produces many effects similar to those of the fixed alkaline salts.

It has been also often employed in paralytic af-feclions; and Coelius Aurelianus directs us to rub palsied limbs with this earth. Mixed with honey, it is em-ploved as a stimulant by Tissot; and with different ointments in the morbus coxarius by De Haen. Two parts of lime, as much wheat flour, with four parts of hog's lard, are employed in the Bath hospital in tumours of the knots (Falconer on Bath Waters). Seve-rinus recommends a formula of quick lime not strictly chemical as a caustic. He mixes it with soap, and sprinkles it with the sharpest vinegar; which will consequently lessen the acrimony of the former ingredients. Quick lime, however, with soap, was long a favourite remedy; and is spoken of with commendation, by Heister, in warts and tumours of every kind. As promoting suppuration, with flour and lard, it is recommended by Valentine; and is generally useful in destroying the spots on the skin, supposed to be owing to the irregular fancies of the mother's appetite during pregnancy.

Internally it is employed only in its watery solution. In the London dispensatory, twelve pounds of boiling distilled water are added to half a pound of lime, and infused for one hour. The Edinburgh college order four ounces of water to be first added to the lime, or as much as it will absorb. When the lime has fallen into a powder, the remainder of the water is mixed with it, stirring the whole together, and the agitation must be often repeated. There is a little too great refinement in both: distilled water is unnecessary in the first, and the frequent stirring in the second. If, in the latter formula, the remaining water is well mixed, and suffered to remain on the lime in a covered vessel for a night, the water will be as strongly impregnated with the earth as its affinity will permit. If the water is heated, the taste is said to be less disagreeable. The lime, in both formulae, is greatly in excess, for a very small proportion only is soluble in water: but it is cheap, or rather, in such small quantities, of no value.

The choice of lime is of consequence in agriculture and the arts, but of little in medicine. Mr. Tennant has informed us that limestone, mixed with magnesian earth, is injurious in agriculture; and the tanner is peculiarly anxious that his lime should be well burnt. Dr. Whytt thought that the lime from oyster shells was the strongest; but the difference seems only to consist in its being more completely calcined to separate the animal gluten. In general, the deficiency in the calcination, if it exists, is compensated by the quantity; and lime water may easily be made as strong as the stomach will admit.

The lime water is a solution of the quick lime in water, and receives no improvement from the ingredients added in the compound sorts which used to be ordered, for they precipitate much of the lime which the water suspended. The taste is acrid and earthy; the smell pungent. With its taste, the lime waterloses its virtues. It hath a strong styptic taste, which is followed by a sweetish one: it changes the juices of blue flowers to a green; it precipitates metallic bodies that are dissolved in acids; it tinges silver of a copper hue-it turns red wine to a dark colour; and by those properties its strength may be estimated.

The specific gravity of water is increased by the lime more than the weight of the calcareous matter taken up, on account, perhaps, of the water being deprived of its air.

If lime water is close kept, it may be preserved many months; but in open vessels the calcareous matter absorbs carbonic acid, and soon separates from the v. concreting on its surface. The earth which floats upon the surface of lime water fresh made, is called ca/cisvivi flores, but it is in reality only the carbonated lime.

Its virtues are also destroyed by every substance containing fixed air; the vitriolic, phosphoric, oxalic, or tartarous acids, as well as by astringents. Milk covers its acrimony very successfully without impairing its virtues.

Lime has been often employed with olive oil in burns; and when we recollect the changes produced on the acrid serum that exudes in the vesicles, by the calcareous earth in Mr. Cleghorn's poultice, little doubt will remain of its having a good effect. If by uniting with this serum it produces some warmth, it will not on this account be injurious.

In the stomach, lime water corrects acidity; but, though out of the body it has been found antiseptic (Hales and Macbride), in the stomach it has probably a contrary effect; for when acids abound, putrefaction is checked. In hot bilious habits, by destroying the natural corrector of bile, acidity, it is also injurious; nor do we think it can strengthen the stomach or assist digestion, as some authors have supposed, except where acids greatly abound. Perhaps, from its antacid power, though its astringency in the primae viae is by no means equivocal, it relieves old diarrhoeas; and in some cases of dysentery has been successful. Grainger, in the Edinburgh Essays, mentions its having succeeded after being continued three weeks, when the patient took three pints daily. Xavier mentions its utility, with milk, in destroying the poison of arsenic in the stomach, or counteracting its effects. We have already mentioned the expectation we had entertained of its dissolving the viscid mucus in this organ, and our disappointment. Some experiments, recorded by Gaber, in the Turin Transactions, seem to support its utility in this respect; but they were not made on the mucus of the stomach. In leucorrhoea. it has been supposed to be very beneficial.

Perhaps the idea of its dissolving viscid fluids occasioned its being employed in intermittents, in pleurisy, in mesenteric and other scrofulous tumours, in rheumatism, and gout. We see Kempf seriously engaged in examining its solvent power on the pleuritic crust of the blood; and the step from calculous to arthritic concretions was too obvious to be overlooked. We cannot deny its utility in gout; but in the other complaints it is certainly of very little importance. It it possessed any power in dissolving viscid mucus, it would very probably be a more useful anthelmintic than it has been found.

From its astringent power it has been an useful ap-t t plication in old ulcers; and from thence it seems to have been supposed serviceable in scurvy, in cancer, and in internal ulcers, when swallowed. Names of uncommon celebrity have given a sanction to its use in these complaints; and Vogel, in a dissertation published at Gottingen in 1769, speaks of its efficacy in cancer, given in the quantity of six and eight ounces of lime water, with as much common water, boiled with sarsa-parilla or guaiacum; interposing, every four or eight days, Beecher's balsamic pills.

In Germany it has been very generally employed in internal ulcers of the uterus, the bladder, and even in ulcers of the lungs. In the latter, however, we are informed by Quarin that it is useless or hurtful. Gir-tanner recommends it as an injection in gonorrhoea; and, from the time of Hippocrates, it has been used as a lotion in all the variety of chronic cutaneous eruptions, especially if attended with exudations. For this purpose it is also taken internally; and it has been recommended to nurses, to prevent the child from being affected. Indeed, cutaneous eruptions are very intimately connected with a disordered state of the stomach, and often with a redundant acid. As an astringent it has been applied externally with a sponge to dropsical swellings; and Fabricius, ab Aqua pendente, informs us, that he cured an ascites by frequently applying a sponge moistened with lime water to the abdomen, and confining it with a tight bandage. Of its lithontriptic power we have spoken at some length in the article Calculus, q. v.

We find numerous cautions in various authors respecting its use in different situations where they suppose it to be injurious. We have already mentioned, however, the inconveniences that might result where the stomach and bowels are loaded with bile; and we should suppose it likewise improper in all cases of hectic fever. We are told, however, that it must be also avoided in all fevers; in hot climates; in dry and hot temperaments; in congestions of blood, either affecting the head or kidneys; in spasms; in the early stages of dysentery; 'in orgasms of the blood, and discharges depending on them;' in inflammatory habits and tense fibres; in obstructions of the bowels, or any diseases in them arising from scybala, till these are removed. Caution is at all times requisite; but we do not think it a medicine of so great power as to require so much attention. The last remark, we would, however, wish to enforce.

See Creta; Neumann's Works; Experiments, etc. on Quick Lime, by Mr. Henry; Macbride's Essay on the dissolving Power of Quick Lime; Percival's Essays, Med. and Exp. edit. 2. p. 328; Lewis's Mat. Med; and the Edinb. Ess. Phys. and Lit. vol. i. art. 13. and vol. ii. art. 8. Dr. Whytt on Oyster Shell Lime Water.