OSCHEOCELE (őoxeov, the scrotum,

Kλn, a tumor). A hernia which has descended into the scrotum.

OSCILLATION (oscillum, an image hung on ropes, and swung up and down in the air). A term applied by Boerhaave to muscular irritability. See Irritability. OSCILLATORIA. A filamentous Algaceous plant, interesting to the physiologist, as exhibiting the first traces of organic contractility in its simplest condition.

OSCILLATORIUS. Versatile, or that which is slightly attached by its middle to any body, so that the two halves are balanced, and swing backwards and forwards; a term applied to the anther of certain plants.

OSCITANCY Coscito, to gape; from os ciere, to stretch the mouth). Yawning, or gaping.

OSCULATOR (osculor, to kiss). A name given to the orbicularis oris, or muscle forming the substance of the lips.

OSMAZOME (ὀσμή, odour, ζωμός, broth). Alcoholic extract of meat. An alcoholic extract obtained from muscular fibre, brain, &c., having the taste and smell of broth.

OSMIUM (оσμn, odour). A new metal lately discovered by Mr. Tennant among platina, and so named by him from the pungent and peculiar smell of its oxide.

Osmic acid. The volatile oxide of osmium, of extremely acid and penetrating odour.

OSSA ALBA. White bones. The name given by Van Helmont to the precipitate formed by the natural salt of the urine, in the production of calculus. It was called by Paracelsus, tartar.

OSSICULUM (dim. of os, ossis, a bone). A little bone. Hence the ossicula auditûs, a series of four small bones contained in the cavity of the tympanum, viz. the malleus, the incus, the orbiculare os, and the stapes; they are subservient to the propagation of sound.

OSSIFICATION (os, ossis, a bone, fio, to become). The formation of bone; the deposition of calcareous phosphate, or carbonate, on the soft solids of animal bodies.

2. Osteo-geny (yéveσis, formation). The growth of bones.

3. Osteo-graphy (ypápw, to describe). A description of the bones.

4. Osteo-logy (λóyos, an account). A treatise of the bones.

5. Osteoma. Bony tumor; a calcareous concretion, occasionally found in the brain.

6. Osteo-malacia (μaλakòs, soft). Softening of the bones, or rachitis.

7. Osteo-pædion (radiov, a child). Lithopædion. An osseous or stony mass into which the foetus is sometimes found to have been converted in the uterus.

8. Osteo-sarcoma (oaps, flesh). Osteosarcosis. The growth of a fleshy, medullary, or cartilaginous mass within a

bone.

9. Ost-hexia (es, a habit). Ossific diathesis; an affection in which soft parts become indurated by a deposit of ossific matter.

10. Ost-itis. Inflammation of a bone.

OSTIOLUM (dim. of ostium, a door). A little door; the orifice of the perithecium of some Fungaceous plants, as sphæria.

OSTIUM (os, the mouth). The door of a chamber, the mouth of a river.

1. Ostium abdominale. The orifice at the fimbriated extremity of the Fallopian tube, the only place in the whole body where a serous membrane communicates with the exterior.

2. Ostium uterinum. The orifice at the uterine extremity of the Fallopian tube.

OSTREA EDULIS (őσтρakov, a shell). The common edible Oyster, a Conchiferous Molluscous animal.

Testæ præparata. Prepared oystershells. The shells are freed from impurities by boiling water, then crushed and pulverized previous to elutriation. They consist principally of carbonate of lime, and therefore possess the same medicinal properties as chalk.

OTALGIA (ους, ὠτος, the ear, ἄλγος, pain). Otitis. Ear-ache; pain in the It has been distinguished into1. Externa, which generally suppurates, and forms what is vulgarly called an im

ear.

1. Osteo-anabrosis (úváßpwois, absorption). A name given by Dr. Cumin to the simple absorption of bone, unaccompanied by secretion of pus. It is by this process that Nature produces the removal of the milk-teeth, &c.

term corrupted from aposteme. It sometimes becomes chronic, and is then called otorrhoea.

2. Interna, or internal imposteme.

OTOCONITE (ous, wros, the ear, Kóvis, dust). A calcareous deposit found in the sacs of the vestibule, analogous to

fishes.

OTOLITES (ous, wròs, the ear, Xi0os, a stone). Calcareous concretions found in the labyrinth of fishes and fish-like amphibia, which, by being in contact with the membranous parts of the labyrinth, increase by their resonance the sonorous vibrations.

OTORRHOEA (ous, wròs, the ear, péw, to flow). The designation of otitis, when it has passed into a chronic state; it then becomes an otitic catarrh.

OTTO or ATTAR OF ROSES. Prepared from the petals of the damask and other roses, by distillation, exposing the product to the night air, and skimming off the fine oil floating on the surface.

OURETIC ACID (oupov, urine). A supposed new acid of Proust and Bergmann, shown by Klaproth to be biphosphate of soda.

OVARIUM (ovum, an egg). An organ containing the ova of animals. The ovaries of the human subject, formerly called testes muliebres, are two small oval bodies placed in the substance of the broad ligaments.

3. Ovule of plants. A small pulpy body, borne by the placenta, and gradually changing into a seed. It consists of two tunics and a nucleus. OVUM. An egg; a small vesicle within the ovarium, containing the embryo, or rudiments of the fœtus.

1. Ovalis. Egg-like. Hence the term ovale is applied to a foramen between the auricles in the foetus.

2. Ovi-duct (ductus, a canal). A name sometimes given to the Fallopian tube, which conducts the ovum to the uterus. 3. Ovi-parous (pario, to bring forth). Animals which bring forth their young in the egg.

Animals which

4. Ovo-viviparous. bring forth their young in a living state, the egg having been previously hatched within the body of the parent.

OXALIC ACID. An acid existing, in the form of an acid salt of potash, in many plants, particularly in the species of Oxalis and Rumex; combined with lime, it forms a part of several lichens.

OXALIDACEÆ. The Wood-sorrel tribe of Dicotyledonous plants. Herbaceous plants, undershrubs, or trees, with leaves alternate; flowers symmetrical; stamens hypogynous; fruit capsular.

Oxalis Acetosella. Common Woodsorrel, a plant which yields the binoxalate of potash, or salt of wood-sorrel.

OVICAPSULE. The capsule of the ovum, which in many invertebrata is insulated from the proper tissue of the ovary, and may even escape with the ovum; but, in the oviparous vertebrata, coalesces with the theca of the ovary, forming there what is termed the calyx.

OVIPAROUS (ovum, an egg, pario, to bring forth). Animals which bring forth their young in the egg.

OVULIGER (ovulum, a little egg, gero, to bear). The name of a new kind of hydatid, supposed to be formed in the articulation of the wrist. See Hydatis.

OVULUM (dim. of ovum, an egg). A little egg; a term commonly used synonymously with ovum. See Ovum.

OXAMIDE. A white insoluble sub

of ammonia by heat. The term is derived from the first syllable of oxalic acid and ammonia.

OXIDATION. The process of converting metals or other substances into oxides, by combining with them a certain portion of oxygen. It differs from acidification, in the addition of oxygen not being sufficient to form an acid with the substance oxidated.

OXIDES, formerly called calces. Substances combined with oxygen, without being in the state of an acid. Oxides are distinguished by the prefixes

1. Proto (πрTos, first), denoting the minimum of oxygen, as protoxide.

2. Deuto (deÚTEρos, second), denoting a second proportion, as deutoxide. This is also called bin-oxide.

3. Trito (Tpiros, third), denoting a third proportion, as tritoxide. This is also called ter-oxide.

OXY- (ofus, acid). A prefix, denoting in some terms, the presence of acidity; in others, the presence of oxygen; in a third class of terms, acuteness of sense or function; and, lastly, sharp-pointed

ness.

A

1. Oxy-gen (yevváw, to generate). gas which forms about a fifth of atmospheric air, is capable of supporting flame, and is essential to the respiration of animals. Its present name was proposed by Lavoisier, from the supposition that it was the sole cause of acidity. It was called by Priestley dephlogisticated air; by Scheele, empyreal,air; and by Condorcet, vital air.

2. Oxygen Water. A solution of oxygen in water. This must not be confounded with oxygenated water, which is the peroxide of hydrogen; nor with Searle's oxygenous aërated water, which is an aqueous solution of the protoxide of nitrogen.

3. Oxy-mel (μéλ, honey). A compound of honey and acetic acid.

4. Ox-acid. An acid containing oxygen. The relative number of atoms of oxygen in different acids formed by the same element with this substance is indicated by prefixes and terminations.

5. Oxy-chloride. A combination of an oxide and a chloride of the same metal, excepting the potassium family. The oxychlorides are commonly termed submuriates, on the supposition that they consist of hydrochloric acid combined with two or more equivalents of an oxide.

6. Oxy-crat (кpáw, to mix). A mixture of vinegar and water.

7. Oxy-croceum. A warm discutient plaister, consisting of wax, resin, pitch, turpentine, saffron, and several gums.

8. Oxy-genation. A term often used as synonymous with oxidation; it differs, however, from it in being of more general import, every union with oxygen being an oxygenation; whereas oxidation takes place only when an oxide is formed.

9. Oxy-alcohol blowpipe. An apparatus contrived by Dr. Marcet for increasing temperature. It consists in urging the flame of an alcohol lamp by a blow-pipe supplied with oxygen gas. The oxygen may be furnished from an air-holder, a gas-bag, or any other vessel in which it has been stored.

10. Oxy-hydrogen blowpipe. An apparatus by means of which a stream of hydrogen is supplied with pure oxygen

as it escapes from a nozzle, and an intense heat thus produced.

11. Oxy-iodine. A name given by Sir H. Davy to anhydrous iodic acid, or the compound of oxygen and iodine. Its compounds with metallic bases were called oxyiodes, and by Gay Lussac, iodates.

12. Oxy-muriate of lime. Chloride of lime, or bleaching powder, prepared by exposing thin strata of recently slaked lime in fine powder to an atmosphere of chlorine. The gas is absorbed in large quantity, and combines directly with the lime.

13. Oxy-muriatic acid. The former name of chlorine; it was also formerly called dephlogisticated marine acid; and by the French, oxygenized muriatic acid. See Chlorine.

14. Oxy-prussic acid. A name formerly given to chloro-cyanic, or chloro-prussic acid, from its being supposed that the hydro-cyanic acid had acquired oxygen on being mixed with chlorine.

15. Oxy-salt. A compound in which oxygen is found both in the acid and the base; thus, in phosphate of soda, it is associated with phosphorus in phosphoric acid, and with sodium in soda.

16. Oxy-opia (ős, vision). Acuteness of sight. Increased sensibility of the retina, by which the smallest objects are clearly seen, for a few moments, in an extremely weak light; yet, excepting at such periods, even larger objects are not seen in the same degree of light.

17. Oxy-phonia (pwvn, voice). Acuteness, or shrillness of voice; synonymous

with paraphonia clangens.

18. Oxy-urus (oùpà, a tail). The Vermicular Ascaris; a parasitic animal, sometimes found in the uterus, or its appendages, the intestines, &c.

OZÆNA (őn, a stench). An ulcer, situated in the nose, discharging a fetid purulent matter, and sometimes accompanied with caries of the bones. In its early state it is generally termed catarrh; when more advanced, it is called cancer of the nostril or throat, as it occupies principally the one or the other of these parts.

OZONE (ő(w, to smell). A new elementary substance, to which Schönbein ascribes the peculiar smell evolved, in electrical operations, at the anode or positive surface. He supposes it to be a constituent of an electrolyte, small quantities of which exist in both air and

water.

PABULUM. Forage, food for cattle. The animal heat and animal spirits are called the pabula vitæ, or food of life. PACCHIONI'S GLANDS. The granulations found in the superior longitudinal sinus of the membranes of the brain.

PACHYBLEPHAROSIS (Taxùs, thick, Bλépapov, the eyelid). Thickening of the tissue of the eyelid, from chronic inflam

mation.

PACHYDERMATA (Taxus, thick, dépμa, skin). Thick-skinned animals, as the elephant; the seventh order of the class Mammalia.

PÆDOTROPHIA (rais, a child, Tpépw, to nourish). That branch of hygiene

which treats of the nourishment of infants and children.

PA'GINA. Literally, a page of a book. A term applied to the surface of a leaf, the upper surface being called pagina superior; the lower surface, pagina inferior.

PAINTERS' COLIC. Colica pictoA species of colic incident to painters, from the use of lead.

rum.

Painters' purge. A medicine used in painters' colic, and consisting of a decoction of half an ounce of senna in a pound of water, mixed with half an ounce of sulphate of magnesia, and four ounces of the wine of antimony.

PAKFONG. The white copper of the Chinese, said to be an alloy of nickel, and zinc.

copper,

PALATUM. Fornix palati. The palate, or upper wall of the mouth.

1. Velum palati. The soft palate; the posterior limit of the palate.

2. Palato-labialis. The name given by Chaussier to the external maxillary or facial artery.

3. Palato-pharyngeus, or thyro-staphylinus. A muscle which arises from the arch of the palate, and is inserted into the thyroïd cartilage and the pharynx. It draws the uvula downwards and backwards, and closes the back of the nostrils. See Salpingo-pharyngeus.

4. Palato-salpingeus. A designation of the circumflexus palati muscle, from its origin and insertion.

PALEA. Chaff. The term paleæ is applied to the minute colourless bracts at the base of the florets of a capitulum; and to the floral envelope of grasses, which immediately surrounds the sexual organs.

PALLADIUM. A new metal, found by Wollaston in the ore of platinum.

PALLIATIVES (pallio, to be concealed; from pallium, an upper garment worn by the Greeks). Medicines which produce merely temporary relief, thus palliating or cloaking the disease.

PALLOR (palleo, to be pale; from Táλλw, to quiver). Paleness, pale colour; the usual colour of those who quiver from fear or other cause.

PALM OIL. The produce of the palm called Elais guineensis, and, according to Burnett, of some species of Bassia and other Sapotaceæ.

PALMA. The palm of the hand; the internal soft part of the hand.

1. Palmar arch. A branch of the

radial artery, which passes over the metacarpal bones. The superficial palmar arch is a continuation of the ulnar artery, which also crosses the metacarpus

2. Palmaris longus. A muscle arising from the inner condyle of the os humeri, and spread out into the palmar aponeurosis, which is finally fixed to the roots of all the fingers. It is a flexor of the

wrist.

3. Palmaris brevis. A muscle arising from the annular ligament of the wrist and the palmar aponeurosis, and inserted into the skin of the inner edge of the hand; it is sometimes called palmaris cutaneus. It contracts the skin of the palm.

PALMA CHRISTI. The Ricinus Communis, or castor oil plant.

PALMACEÆ. The Palm tribe of Monocotyledonous plants. Plants with an arborescent trunk, covered with the sheathing bases of leaves; leaves terminal, clustered, pinnate, or flabelliform; flowers hexapetaloïdeous, stamens definite; ovarium superior, 3-celled; fruit baccate, or drupaceous, with fibrous flesh.

PALMINE.

commerce.

Palmitine. Palmitate of glyceryl. PALO DE VACA. The Cow Tree, a native of the Caraccas, from which the vegetable milk, or glutinous or milky sap, is obtained by incision.

PALPATION (palpo, to feel). The act of feeling; manual examination, or a method of exploring the abdomen by touch and pressure, for the purpose of ascertaining its form, size, &c.

PALPEBRA. The eyelid. The utmost edge of the palpebra, out of which the hairs grow, is called cilium, a term also applied to the hairs themselves; while the eyebrow, or ridge of hair above the eyelid, is called super-cilium.

PALPITATION (palpito, to throb). An increase in the force or frequency of the heart's contraction, or in both. When this affection results from loss of blood, it is termed reaction.

PAMPINIFORM (pampinus, a tendril, forma, likeness). Resembling a tendril; as applied to the smaller veins of the spermatic cord, from their peculiar tendril-like arrangement.

PAN- (neuter gender of Tas, all). Panta. All; every one. Hence

1. Pan-chrestus (xonoτòs, useful). A term applied to a medicine in the same sense as panacea, from its general usefulness.

2. Pan-chymagogues (xvμòs, juice, ayw, to expel). The former name of purgatives which caused evacuations mixed nearly equally with the humors of the intestinal canal. Thus, calomel was called panchymagogum minerale.

3. Pan-demic (dñμos, the people). Affecting all the people of a district; a term synonymous with epidemic.

4. Pant-agoga (ayw, to expel). Medicines which expel all morbid matters; a term synonymous with panchymagogues.

5. Panto-phobia (póßos, fear). A fear or dread of all things; a term used by the old writers as expressive of some of the symptoms of hydrophobia.

1. Panacea anticancrosa. The name given by Mr. Justamond to the liquid invented by him for external use in cancers; it partook considerably of the nature of the tinctura ferri muriatis, which, indeed, with an equal quantity of spirit of wine, was sometimes substituted for it.

2. Panacea duplicata vel Holsatica. The bisulphate of potass.

3. Panacea Glauberiana. The Kermes mineral, a sulphuret of antimony.

4. Panacea lapsorum. This name has been given to Arnica, or Leopard's-bane, a plant of the order Compositæ, from its long reputation in internal pains and congestions from bruises, or more probably in prolapsus.

5. Panacea mercurialis. Calomel; the sub-muriate or chloride of mercury.

6. Panacea vegetabilis. The croci stigmata, or saffron.

PANADA (pane, bread, Ital.). Bread pap; bread boiled in water to a proper consistence, as food for children.

PANARIS (Tapà, near, övvk, the nail). Panaritium; a term probably corrupted from paronychia, or whitlow.

An

PANAX QUINQUEFOLIUM. Araliaceous plant, the root of which constitutes the American ginseng, or radix gingeng. The Asiatic ginseng, or radix ninsi, is the root of the Panax schinseng.

PANCREAS (πãν, all, кρéas, flesh). A conglomerate gland, situated transversely across the posterior wall of the abdomen. In cattle it is called the sweetbread.

1. Small pancreas. A small glandular mass, frequently found beneath the pancreas, and of similar structure. The French term it pancreas d'Aselli.

2. Pancreatic duct. The duct formed by the union of the numerous excretory ducts proceeding from the lobules of the pancreas.

3. Pancreatic juice. The peculiar fluid secreted by the pancreas.

4. Pancreat-algia (äλyos, pain). Pain of the pancreas. The term is seldom used.

5. Pancreat-itis. Inflammation of the pancreas; from pancreas, and the terminal particle itis.