DACRYO'MA (dakρúw, to weep). An impervious state of one or both of the puncta lacrymalia; so named from the running down of the tear over the lower eye-lid.

DÆMONOMANIA (daíuov, a demon, uavía, madness). A species of melancholy, in which the patient supposes himself possessed by demons..

DAGUERREOTYPE. A process by which all images produced by the camera obscura are retained and fixed in a few minutes upon surfaces of silver by the action of light. The name is derived from Daguerre, the inventor.

DAHLINE. A vegetable principle discovered in the dahlia, similar to inulin and starch.

DAMPS. The permanently elastic fluids which are extricated in mines. These are choke damp, or carbonic acid; and fire damp, consisting almost solely of light carburetted hydrogen, exploding on contact with a light.

DANDRIFF. A Saxon term for scurf of the head. See Pityriasis.

DAPHNE MEZEREON. The Common Mezereon, or Spurge Laurel; a plant of the order Thymelacea, yielding the Mezereon bark.

1. Daphne gnidium. The bark of this species is employed in France as a vesicatory, under the name of garou. The fruit is the KÓKKOS Kvidios, or Gnidian berry, of Hippocrates.

2. Daphne laureola. An indigenous species, agreeing in property with the preceding.

3. Daphnin. A peculiar crystalline principle, found in the Daphne mezereon, but not constituting its active principle. See Lagetta.

DARTOS (dépw, to excoriate). Darsis. A contractile fibrous layer, situated immediately beneath the integument of the scrotum.

Dartoid tissue. The structure of the dartos, intermediate between muscle and elastic fibrous tissues.

DARTRE (dapròs, a shell or crust, from dépw, to excoriate). Tetter; a term which has been used at different times to designate almost all diseases of the skin.

DATES. The drupaceous fruit of the Phoenix dactylifera, or Date Palm tree.

DATURA STRAMONIUM. The Common Thornapple; a plant of the order Solanaceae, the effects of which are similar to those of belladonna.

Daturia. A vegetable alkali said to exist in the Datura Stramonium.

DAUCUS CAROTA. Common or Wild Carrot ; an indigenous Umbelliferous plant. The officinal root is that of the variety sativa, the cultivated or garden carrot. The officinal fruits, incorrectly called carrot-seeds, belong to the wild carrot.

1. Rob dauci. Carrot juice; the expressed juice of the carrot root. By standing, a feculent matter, called amylum dauci, recently employed in medicine, is deposited.

2. Carotin. A crystalline, ruby-red, neutral substance obtained from the carrot root.

DAY-MARE. Ephialtes vigilantium. A species of incubus, occurring during wakefulness, and attended with that severe pressure on the chest which peculiarly characterizes night-mare.

DAY-SIGHT. An affection of the vision, in which it is dull and confused in the dark, but clear and strong in the day-light; it is also called nyctalopia, or night-blindness. Hens are well known to labour under this affection; hence it is sometimes called hen-blindness.

DEBILITY (debilis, weak). Weakness, feebleness, decay of strength both in mind and body.

DECANDRIA (déka, ten, ávǹp, a man). A class of plants in the Linnæan system, characterized by having ten stamens.

DECANTATION. The pouring off of clear fluid from sediments.

DECIDUA (decido, to fall off). A spongy membrane, or chorion, produced at the period of conception, and thrown off from the uterus after parturition.

1. Decidua reflexa. That portion of the decidua which is reflected over, and surrounds the ovum.

2. Decidua vera. That portion of the decidua which lines the interior of the uterus; the non-reflected portion.

DECOCTION (decoquo, to boil away) 1. The operation of boiling. 2. A solu. tion of the active principles of vegetables, obtained by boiling them in water. DECOLLATION (decollo, to behead, from collum, the neck). Decapitation. The removal of the head.

DECOMPOSITION. Analysis. The separation of the component parts or principles of bodies from each other. DECORTICATION (de, from, cortex, bark). The removal or stripping off of the bark, husk, &c.

DECREPITATION (de, from, crepitus, crackling). The crackling noise which takes place when certain bodies, as common salt, part with the water which they contain, by the application of heat, and fall to pieces.

DECUSSATION (decusso, to cross like an X). A term applied to parts which cross each other, as the optic nerve.

DECUSSORIUM (decusso, to divide). An instrument for depressing the dura mater, after trephining.

DEFLAGRATION (deflagro, to be utterly consumed by fire). The oxidation of metals by mixing them with nitrate or chlorate of potash, and projecting the mixture into a red-hot crucible.

1. Deflagrating Mixtures. These are generally made with nitre, the oxygen of which is the active ingredient in promoting their combustion.

2. Deflagrator. The name given by Dr. Hare to a very effective battery, in which the plates were so connected together as to admit of the whole being immersed into the exciting liquid, or removed from it, at the same instant.

DEFLUXION (defiuo, to flow off). Destillatio. Catarrh. This term was formerly used, as well as fluxion, to denote a swelling arising from the sudden flow of humors from a distant part.

DE FRUTUM. A mixture made of new wine, mentioned by Celsus. The term appears to be derived à defervendo, contracted for defervitum, i. e. decoctum. See Rob.

becoming liquid by their attracting moisture from the air.

DELIQUIUM ANIMI (delinquo, to leave). Syncope; fainting.

DELIRIUM (deliro, properly, to slip out of the furrow; from de, and lira, a furrow; figuratively, to talk or act extravagantly, to swerve from reason). Raving; phrensy; disorder of the brain.

1. Delirium tremens. A barbarous ex

pression, intended to convey the idea of delirium coexisting with a tremulous condition of the body or limbs. It has been called brain fever, a peculiar disorder of drunkards, delirium et mania è ebriosorum, &c. potu, delirium ebriositatis, erethismus

2. Delirium traumaticum. A similar

disease which occurs after serious accidents or operations. Dupuytren.

DELITESCENCE (delitesco, to lie hid). A term used principally by the French physiologists to express a more sudden disappearance of the symptoms of inflammation than occurs,in resolution.

DELPHINIC ACID. An acid procured from the oil of the Delphinus delphis, or dolphin.

DELPHINIUM STAPHISAGRIA. Stavesacre; a Ranunculaceous plant, of narcotico-acrid properties, depending on the presence of a peculiar principle called delphinia, and a volatile acid. The seeds have been used to destroy pediculi, and are hence termed by the Germans louseseeds.

DELTOIDES (déλra, the Greek letter A, and eidos, likeness). The name of a muscle of the humerus, from its supposed resemblance to the Greek letter A.

DEMENTIA (de, from, mens, the mind). Idiotcy; absence of intellect. DEMI-BAIN. The French term for a hip-bath; literally half-bath.

DEMULCENTS (demulceo, to soften). Softening and diluting medicines.

DENIGRATION (de, from, and niger, black). Another term for Melanosis, derived from its black appearance.

DENS. A tooth. The first set of teeth in children, called the milk teeth,

DEHISCENCE (dehisco, to gape or open). A term used in botany to denote the opening of a ripe fruit for the discharge of the seeds.

DEJECTIO ALVI'NA (dejicio, to cast down). The discharge of the fæces.

DELIQUESCENCE (deliquesco, to melt). The property of some salts, of

lateral teeth. The first two pairs have been termed bicuspidati, from their two conical tubercles; the three next, the large grinders or multicuspidati.

32.

4. The teeth in the Adult areIn. ; Can.; Mol. In Infants:

In. ; Can. ; Mol. ―=20.

5. In each tooth are observed, the Crown, above the alveolus; the Neck, just below the crown; and the Fang or fangs, within the alveolus.

6. The Structure of the Teeth is, 1. Enamel, encasing the crown, and the hardest production of the body; 2. Bone, constituting the whole of the root, and the interior of the crown; and 3. the Pulp, a bulbous prolongation of the mucous membrane of the gums, which fills the cavity of the teeth, forming their

nucleus.

DENSITY (densus, thick). The property of a body, by which a certain quantity of matter is contained under a certain

bulk. It is opposed to rarity.

DENTA'TA (dens, a tooth). The name of the second vertebra, so called from its projecting tooth-like process.

DENTIFRICE (dens, a tooth). Various powders used for cleaning the teeth.

DENTITION (dentio, to breed teeth, from dens, a tooth). Cutting the teeth; teething. See Dens.

Dedentition. The loss or shedding of the teeth.

DENUDATION (denudo, to make

2. Dephlogisticated marine acid. The name given by Scheele to chlorine.

DEPILATORY (de, from, pilus, a hair). An application for removing hair from any part of the body.

DEPLUMATION (de, from, pluma, a feather). A disease of the eyelids, in which the hair falls off.

DEPOSIT (depono, to lay down). A sediment, or any thing laid down. The mechanical deposits of urine are divided. by Dr. Prout into the pulverulent, or amorphous sediments; the crystalline sediments, or gravel; and the solid concretions, or calculi, formed by the aggregation of these latter sediments.

Calculus.

See

DEPRESSION (deprimo, to press down). Couching; an operation for cataract, consisting in the removal of the opaque lens out of the axis of vision, by means of a needle.

DEPRESSOR (deprimo, to press down). A muscle which depresses any part, as those of the ala of the nose, of the angle of the mouth, of the lower lip.

DEPRIMENS OCULI (deprimo, to press down). A name given to the muscle in drawing the eyeball down. rectus inferior, from the action of this

See Attollens oculi.

DERBYSHIRE NECK. A name

given by Prosser to bronchocele, from its frequency in the hilly parts of that county.

DEOBSTRUENTS (de, from, obstruo, to obstruct). Medicines for removing obstructions.

DEOXIDATION (de, from, and oxidation). The separation of oxygen from a body; the reducing a body from the

state of an oxide.

DEPHLEGMATION (de, from, and phlegma, a watery distilled liquor, as distinguished from a spirituous liquor). The depriving a body of water. Thus, when the fluid is simply rendered stronger, as in the case of alcohol, by bringing over the spirit by distillation, and leaving behind the superfluous water, the process is called dephlegmation, or concentration. DEPHLOGISTICATED (de, from, and phlogiston, the inflammable principle). Oxidised; deprived of phlogiston.

1. Dephlogisticated air. Oxygen gas; called by Scheele empyreal air, and by Condorcet vital air.

found abundantly in Derbyshire.

DERIVATION (derivo, to draw off water from its regular channel). Revulsion, or drawing away of the fluids of an inflamed part, by applying blisters, &c., over it, as in pleuritis; or at a distance

from it, as sinapisms to the feet, in comatose affections. Agents, producing this effect, are termed derivatives

DERMA (dépμa). Dermis, or chorium. The cutis vera, or true skin, consisting of a superficial or papillary layer, and a deep layer or corium. See Cuticle.

1. Dermic. A term applied to the action of remedies through the skin.

2. Dermoid (eldos, likeness). A term applied to tissues which resemble skin.

DERMATOLYSIS (dépua, skin, λów, to loosen). Cutis pendula. A form of hypertrophy of the skin, characterized by great extension of this organ, which is thrown into folds, forming occasionally large pendulous masses.

DEROSNE'S SALT. Narcotine; Opiane. A crystalline substance, obtained by treating opium with æther.

DESCENDENS NONI. The descending cervical branch of the ninth pair of nerves, or hypoglossal.

DESICCATION (desicco, to dry up). The operation of drying; the state of being dry.

DESPUMATION (de, from, spuma, foam). The clarifying of a fluid, or a separating its foul parts; literally, the throwing off of froth or foam.

DESQUAMATION (de, from, squama, The falling off of the cuticle,

a scale).

in the form of scales.

DETERGENTS (detergo, to wipe away). Substances which cleanse wounds, ulcers, &c.

DETERMINATION (de, from, terminus, a bound). An excessive flow of blood to a part. DETONATION (detono, to thunder). A sudden combustion and explosion.

DETRITUS (worn down). Suppuration; softening; ramollissement.

DETRUSOR URINE (detrudo, to thrust out). The aggregate of the muscular fibres of the bladder which expel the urine.

DEUTO- (deÚTepos, second). A prefix denoting two, or double, as deut-oxide, having two degrees of oxidation; deutochloride, &c.

DEUTOXIDE (deúтepos, second). A term applied to a substance which is in the second degree of oxidation. This term is often used to denote a compound of 3 atoms of oxygen with 2 of metal, as in deutoxide of manganese, of lead, &c.

DEVONSHIRE COLIC. Colic of Poitou. A species of colic, occasioned by the introduction of lead into the system, and named from its frequent occurrence in Devonshire and Poitou, where lead was formerly used to destroy the acidity of the weak wines and cider made in those parts. It is also called Painters'

colic, from the same cause.

DEW. The moisture insensibly deposited from the atmosphere on the surface of the earth. It occurs whenever that surface is lower in temperature than that of the dew-point of the atmosphere immediately in contact with it.

Dew-point. That temperature of the atmosphere at which its moisture begins to deposit.

DEXTRIN (dexter, right). Mucilaginous starch, prepared by boiling a solution of starch with a few drops of sul

phuric acid. Its name is derived from its property of turning the plane of the polarization of light to the right hand.

DIA (dia). A Greek preposition, denoting through. Words compounded with da imply extension, perversion, transition; also that which in English and Latin is expressed by the prefixes di- or dis-, as in divido, to divide; disjungo, to disjoin.

1. Di-aresis (diapéw, to divide). A solution of continuity. This term was formerly applied to denote a cause of external aneurysm.

A

2. Di-arthrosis (ap@pov, a limb). species of moveable articulation, constituting the greater proportion of the joints of the body.

3. Dia-betes (Baivw, to go; or diaẞýτns, a siphon). An immoderate flow of urine. This disease has been termed diarrhoea urinosa, hydrops ad matulam, hyderus, dipsacus, morbus sitibundus, fluxus urinæ, nimia urinæ profusio, polyuria. It is termed insipidus (tasteless), in which the urine retains its usual taste; and mellitus (honied), in which the saccharine state is the characteristic symptom.

Diabetic sugar. The sweet principle of most acid fruits, and of diabetic urine. It is also termed starch sugar, sugar of fruits, grape sugar, glucose, &c.

4. Dia-chylon (xvλòs, juice). An emollient digestive plaster, formerly prepared from expressed juices. It forms the Emplastrum plumbi of the Pharmacopœia.

5. Dia-codium (кwdeia, a poppy-head). The old name of the Syrupus Papaveris, or syrup of poppies.

6. Dia-gnosis (yvwσkw, to discern). The act of discerning, or distinguishing, in general; in medicine, the distinction of diseases.

7. Di-agometer Electrical (diάyw, to conduct, μéтpov, a measure). An apparatus used by Rousseau for ascertaining the conducting power of oil, as a means of detecting its adulteration. It consists of one of Zamboni's dry piles, and a feebly-magnetized needle, moving freely on a pivot. The deviation of the needle is less in proportion to the low conducting power of the interposed substance.

8. Dia-grydium, or Dia-crydium. One part of quince juice, and two parts of scammony, digested for twelve hours, and evaporated to dryness.

9. Dia-luric acid (oipov, urine). A new acid produced by the decomposition of alloxantin.

nutrition of the embryo. The name is derived from duornu, to separate, in

12. Di-orthosis (opłów, to regulate). The restoration of parts to their proper situation; one of the ancient divisions of surgery.

13. Dia-pente (Tévтe, five). Equal parts of myrrh, laurel berries, gentian root, ivory shavings, and birthwort root.

14. Dia-pedésis (andάw, to spring). A term formerly used to denote external aneurysm. 'Per diapedesin,' says Silvaticus, id est, rarefactis ejus tunicis.'

15. Dia-phanous (paívw, to shine). Transparent; the name given by Pinel to the serous membranes, from their transparency when detached from their organs, as the arachnoïd, the omentum, In Chemistry, the term denotes per

&c.

meability to light.

two supposed constituents of starch.

26. Dia-stasis (duoτnu, to separate). A forcible separation of bones, without fracture.

27. Dia-stole (diaσTéλw, to dilate). The dilatation of the heart and arteries. It is opposed to Systole. (θερμαίνω, to warm). A term denoting free permeability to heat. It is synonymous with transcalent.

28. Dia-thermanous

29. Dia-thermancy. The property possessed by nearly all diathermanous bodies, of admitting the passage only of certain species of calorific rays. When the quantity of heat transmitted independently of the quality is to be denoted, the term diathermaneity has been suggested by Melloni, in order to preserve the same

17. Dia-phoretics (popéw, to carry). Medicines which increase the natural exhalation of the skin; when they are so powerful as to occasion sweating, they have been called sudorifics.

18. Dia-phragma (ppάoow, to divide). The midriff, or diaphragm: the transverse muscular septum which separates the thorax from the abdomen.

19. Dia-phragmatic Gout. A term applied by Butter to the affection now called Angina Pectoris.

20. Dia-phragmatitis (ppáσow, to divide). Inflammation of the diaphragm. A term sometimes applied to that variety of partial pleurisy in which the effused fluid exists between the base of the lung and the diaphragm.

21. Dia-physis (pów, to be ingrafted). A term applied to the middle part, or body, of the long or cylindrical bones.

22. Dia-pnoics (diaπvon, perspiration). A term synonymous with diaphoretics and sudorifics.

23. Dia-rrhoea (péw, to flow). A flux, or flowing through, or looseness. It is termed fluxus ventris, alvus fusa, lienteria, &c.

24. Dia-scordium. The Electuarium opiatum astringens; an electuary made of Water Germander or Scordium leaves, and other ingredients.

25. Dia-stase. A vegetable principle, allied in its general properties to gluten, which appears in the germination of barley and other seeds, and converts

indicating the analogous property in relation to light.

30. Dia-thesis (TiOnμ, to arrange). Constitutional disposition. Examples of diathesis are the rheumatic, the scrophulous dispositions, &c.

31. Di-uresis (oupéw, to make water). A copious flow of urine. Hence the term diuretics is applied to medicines which promote the secretion of urine.

DIADELPHIA (dis, twice, adeλpos, a brother). The seventeenth class of plants in Linnæus's system, in which the filaments of the stamens are united into two parcels, or brotherhoods.

DIAMOND. A gem; the crystallized and pure state of carbon, and the hardest and most brilliant body in nature.

DIANDRIA (dis, twice, avǹp, a man). The second class of plants in Linnæus's system, characterized by the presence of

two stamens.

DIARY FEVER (dies, a day). Ephemera. The simplest form of fever, distinguished by Dr. Fordyce as simple fever; it has one series of increase and decrease, with a tendency to exacerbation and remission, for the most part appearing twice in twenty-four hours.

DICHOTOMOUS (dixa, doubly, Téμvw, to divide). A term applied to stems or branches which bifurcate, or are continually divided into pairs.

DICOTYLEDONES (dis, twice, koTuλndwv, a seed-lobe). Plants whose embryo contains two cotyledons or seedlobes. See Cotyledon.