LARYNGECTOMY

and lower parts into which the layrnx may be conveniently divided. Laryngectomy (λapvy, εKтоμn, a cutting out). An operation for the extirpation of the larynx.

Laryngis/mus (Zapvyyišw, to vociferate). A term loosely applied to various spasmodic affections of the larynx. L. Stridulus. Same as Laryngospasm.

Laryngitis (apvys, ris, inflammation). A catarrhal inflammation of the larynx accompanied by sore throat, hoarseness, and, usually, painful deglutition and cough. In severe cases there may be oedema, dyspnoea, and suffocation. In infants it is much the same disease as croup. It also accompanies malignant affections of the throat and trachea, such as diphtheria, cancer, etc.

Laryn'go-fis'sure (λapvy, fissura). Division of the larynx for the removal of tumors or foreign bodies.

Laryngog'raphy (hapvys, ypaow, to write). A description of the larynx. Laryngology (λapvyš, λoyoç, a treatise). A treatise on the larynx.

Laryngoparalysis (λαρυγξ, παράλυσις, palsy). Loss of the voice or paralysis of the vocal cords from nervous affections, not local disease.

Laryngop'athy (λapvyš, ñaboç, a suffering). A term including all affections of the larynx.

Laryngophantom (λαρυγξ, φαντασμα, α vision). An artificial larynx designed for illustrative purposes.

Laryn'go-pharyngeal (λapvyš, papvyk, the throat). Pertaining conjointly to both larynx and pharynx.

Laryngoph'ony (λapvy, pwvn, the voice). The sound of the voice observed in the auscultation of the larynx with the stethoscope; also the sound of the voice observed in the auscultation of a large cavity in the lung. Laryngople'gia (λapvy, λnyn, a stroke). Paralysis of the muscles of the larynx. Laryngospasm (λαρυγξ, σπασμός, spasm). Spasmodic contraction or closure of the glottis; spasmodic croup, as distinguished from inflammatory croup. Laryngoscope (λapvyš, σKOñεw, to observe). An instrument for examination of the larynx.

a

Laryngo-stenosis (λαρυγξ, στένωσις, 2 contraction). Contraction in size of the larynx. Laryngot'omy (λapvys, reμvw, to cut). The operation of incision of the larynx.

Laryngo-tracheal (λapvyš, τpaxɛia, the windpipe). Pertaining conjointly to the larynx and the trachea.

Laryngotracheotomy (λαρυγξ, τραχεια, Toun, a section). That form of the operation of tracheotomy in which the cricoid cartilage, and some of the upper rings of the trachea are divided.

Larynx (apvys,). The upper part of the air passage, between the trachea and the base of the tongue. It comprises three single cartilages, the thyroid, cricoid, and epiglottis, and three pairs of cartilages, the arytenoid and those of Santorini and Wrisberg. It is lined with an extremely sensitive mucous membrane, which forms two transverse lipped folds that constitute the vocal cords.

Lascivious (lascivia,wantonness). Libidinous. Wanton. Having an unlawful desire. Las/situde (lassus, tired). A state of exhaustion or weakness, arising from causes other than fatigue.

La'ta. See Miryachit.

La'tency (lateo, to be hid). The condition of being latent or concealed. La'tent (lateo). Concealed. Not manifest. In physics, applied to heat that apparently disappears when a liquid is vaporized or a solid melted. L. Period, the time required for the incubation of a disease. Lat/erad (latus, the side). Toward the lateral aspect of.

Lat'eral (lateralis). At, belonging to, or pertaining to the side. The aspect of the side viewed from the middle. L. Column, that column of the spinal cord between the antero- and postero-lateral fissures. L. Operation, that form of operation in lithotomy in which the opening is made on the left side of the perinæum. L. Plates, the part of the mesoblast lying external to the provertebræ. L. Sinuses, the two veins of the dura mater situated in the attached margin of the tentorium cerebelli.

Lateri'tious (later, brick). Pertaining to an urinary sediment resembling brick-dust. Latero-cervical (lateralis, cervix, the neck). At or about the side of the neck. Latero-dor'sal (lateralis, dorsum, the back). At or near the side of the back. Latero-flex/ion (lateralis, flecto, to bend). Bending to one side.

Lateropulsion (lateralis, pello, to drive). An involuntary motion or bearing to one side. La'tex (Lat., liquid). The sap or the juice of the tubes or vessels of plants.

LATHYRUS CICERA

See

Lath'yrus Cic'era. A species of vetch, commonly known as "chick-pea." Lathyrism.

Lath'yrism (2a0vpis, spurge). The convulsive movements, tremors and paraplegia arising from the use of the seeds of Lathyrus cicera.

Latis'simus (superl. of latus, wide). An adjective signifying widest. It is used as a descriptive term with certain muscles. L. Colli. See Muscle (Platysma Myoides). L. Dorsi. See Muscle. Laud'anin. One of the alkaloids of opium. It is soluble in chloroform and alkaline solutions.

Laud'anum. See Opium.

Laugh'ing (Sax. hlehhan). A succession of rhythmic, spasmodic expirations with open glottis and vibration of vocal cords. L. Gas. See Nitrogen. Laur'el. See Kalmia.

La'va (Lat., a flood or torrent). The molten ejecta of a volcano.

Lavage (Fr.). Irrigation or washing out the stomach.

Lavamen'tum (lavo, to wash). An injection.

Lavender, or

Lavan'dula. The flowers of L. vera. Properties due to a volatile oil. Aromatic, stimulant and carminative, but used mainly as a flavor and adjuvant of other medicines. L. Ol., the volatile oil distilled from the whole herb. Dose mj-v. L. Ol. Florum, the oil distilled from the fresh flowers, preferable to preceding. Dose mj-v. A constituent of Spt. Odoratus. L. Spt., 3 parts of the oil in 97 of alcohol; a perfume. Dose 3 ss-j. L. Tinct. Comp., oil of lavender 8, oil of rosemary 2, cinnamon 18, cloves 4, nutmeg 10, red saunders 8, alcohol 680, water 270, dilute alcohol to make 1000. Dose 3 ss-ij, a constituent of Fowler's solution.

Laveran, Corpuscles of. See Bacillus, of Malaria, and Plasmodium.

Lax (laxo, to loosen). Loose. Not tense. Lax'ative (laxo). An agent that loosens the contents of the bowels. gative.

A mild pur

antine establishment. Also, a place for fumigation and disinfection. Lead. See Plumbum.

Lead-poisoning. Either due to accidental or industrial introduction of lead into the system. The symptoms are disturbed nutrition, anæmia, the gingival line, lead colic, constipation, pains in the limbs, local muscular paralysis (wrist-drop) and wasting, saturnine encephalopathy, etc. The treatment consists in stopping ingress of lead to the system, its elimination by iodide of potassium, aperients, etc. Leaf Cup. See Bearsfoot. Lean'ness. A condition of having less than the normal amount of flesh. It may be natural, or the result of disease. Leav'en (levo, to raise). A name given to several species of ferments belonging to the class of saccharomycetes, of which the culture known as "sour dough" is a common example.

Lecithin (Koç, yolk of egg). A class of nitrogenized, phosphorized substances occurring in brain- and nerve-tissue. Lectua'lis (dim. of lectus, a bed). Pertaining to a bed or couch. Also, diseases that confine one in bed. Also, a patient. Lec'tulus (dim. of lectus). A bed or couch. Also, a couch or mattress containing medicinal substances. L. Medicatus, a dry fermentation.

Leech (Sax. lace, physician). Hirudo Medicinalis, of the order Hirudinea, class Annelida, sub-kingdom Vermes. To extract blood by leeching. L., Artificial, the apparatus for cupping.

Lees (A. S. læs, dregs). The dregs or solid matter held in suspension by a liquid, that finally settles at the bottom of the vessel. Especially the sediment of vinous liquors. Leg. The lower extremity of man, especially that part from the knee to the ankle. An organ of locomotion of man and other animals.

Legitimacy (legitimo, to make lawful). The condition of being within the bounds of the law. Also, the statutory recognition of a child born within wedlock, or within a period of time necessary to gestation, which may elapse after the death of the father.

Legu'min. See Casein.

Leiomyo'ma (2105, smooth, μvs, a muscle). A form of myoma characterized by unstriped muscular fiber.

Leipothymia (λɛw, to relinquish, vuos, the mind). A term denoting sainting or syncope.

LEITER'S TUBES

Lei'ter's Tubes. Tubes of soft, flexible metal designed for bending about any part of the body. Cold water is passed through the tubes, thereby reducing the temperature of the parts encased. Lem/on. See Limon.

Lens (Lat., a lentil). A regularly-shaped piece of glass or crystal for the refraction of rays of light. The crystalline lens of the eye. L., Achromatic. See Achromatic. L., Biconcave, a thick-edged lens having concave spherical surfaces upon its opposite sides, called also a negative or minus lens; used in spectacles to correct myopia. L., Biconvex (positive or plus lens), a thin-edged lens; it has two convex surfaces; used to correct hyperopia. L., Cylindrical (either minus or plus), one ground upon a cylindrical tool, ie, one with a plane surface in one axis and a concave or convex surface in the axis at right angles to the same. L., Decentered, one in which the optical center is not opposite the pupil of the eye. L., Periscopic, one with concavo-convex or convexo-concave surfaces, the opposite sides being of different curvatures; to avoid spherical aberration, and to gain a greater field of clear vision, called meniscus lenses. L., Plano-concave, Planoconvex, Plano-cylindrical, has a plane surface upon one side and a curved surface upon the reverse. L., Spherical, one whose curved surface is a segment of a sphere, either concave or convex, in contradistinction to a cylindrical lens. L., Sphero-cylindrical, one with a spherical surface upon one side, and a cylindrical upon the reverse, used for the correction of either myopia or hyperopia, combined with astigmatism. See Spectacle-Lenses. Lenticular (dim. of lens). Pertaining to or resembling a lens; also a descriptive term applied to an instrument with a curved cutting edge for removing the rough edges of bone made by the trephine. L. Ganglion. See Ganglion. L. Nucleus, the extraventricular portion of the corpus striatum. Lenti'go (lens). Freckles, Ephelides. Circumscribed spots or patches of pigment, small in size and occurring mainly on the face and hands. Freckles rarely occur before eight years, and are not common in aged persons. Most frequent among people of light complexion.

Len'tor (lentus, adhesive). Viscidity of a liquid.

Leonti'asis (leo, a lion). See Elephantiasis. L. Ossa. See Osteitis.

Lep'er (2роç, scaly). One affected with leprosy.

Lep'ido- (iç, a scale). A Greek prefix signifying a scale, or scaly.

Lep'idoid (ETIS). Having the appearance of a scale.

Lepidoplastic (hem, haoow, to form). Forming scales.

Lepidoptera (λɛπıç, πτɛрov, a wing). An order of insects distinguished by featherlike scales and a spirally coiled suctorial apparatus. The order includes butterflies and moths.

Lepid'osis (TIC). Same as Ichthyosis. Also, a synonym for Lepra.

Lep'ocyte (2оç, a husk or sheath, KʊTO, a cell). A nucleated cell. Lep'othrix (2ɛñоç, Oрığ, a hair). A condition of the hair, especially that of the armpits, in which the shaft becomes encased in a sheath of hardened sebaceous matter. Also, the typical thread-like form assumed by certain species of bacteria of the order Schizomycetes.

Lep'ra (empa, a leper). Leprosy. Elephantiasis Græcorum. Leontiasis. Psoriasis. An endemic, chronic, and highly malignant disease, somewhat analogous to syphilis in pathological character. Prevalent in Europe and Asia, especially along the Mediterranean shores. Rare in North America, except on Pacific coast. A constitutional disease preceded by malaise, debility and languor, followed by characteristic bullous, macular, or tubercular lesions of the skin. L., Tuberculated, characterized by massive infiltrations and the formation of tubercles, commonly on the face, breasts, scrotum and penis. L., Non-tuberculated, a form of the disease characterized by macular patches that spread peripherally, until much or the whole of the skin is involved. In later stages the disease extends into the subcutaneous tissues, muscles and bones, resulting in disarticulation and destruction of the joints of the fingers and toes. This form of leprosy is nearly always marked by anææsthesia of the parts involved. L., Mixed Tuberculated, involves both forms of the disease. There is very strong evidence in favor of the contagious character of the disease, and, also, that it is intimately connected with the development of a specific bacillus.

Leprophthalmia (empa, opłaĥμos, the eye). Ophthalmia of a leprous char

acter.

Leprosy. See Lepra.

LEPTANDRA

Leptan'dra. Culver's Root. The rhizome and rootlets of L. virginica. Properties thought to be due to a glucoside, leptandrin. A tonic, laxative, and cholagogue. Indicated in indigestion and chronic constipation. Dose of the ext. gr. j-iij, of the fld. ext. mxx-3 j.

Lep'to- (2εTOÇ, thin, small, slender). A Greek prefix, signifying small or slender. Leptoceph'alic, or

Leptoceph'alous (2ɛñтoç, Kɛpɑλŋ, head). Having an abnormally small head. Leptocephalus. A monstrosity with an abnormally small head.

Leptomeningitis (λεπτος, μηνιγξ, a membrane). Inflammation of the pia and arachnoid of the brain and the spinal cord, in contradistinction to Pachymeningitis, though meningitis alone usually signifies the same as leptomeningitis. See Meningitis. L. Cerebralis, an inflammation, confined usually to the pia mater of the convex surface of an anterior lobe of the cerebrum. L. Spinalis, any inflammation of the pia mater of the spinal cord. Lep'torhine. See Index. Lep'tothrix (heπτos, Opiš, a hair). genus of the family Bacteriaceës, whose elements form straight filaments, often of great length. Possibly indistinguishable from the genus Bacillus. The only L. studied is L. Buccalis, very common in the mouth, playing a large part in the formation of dental tartar and the production of caries of the teeth. L. Gigantea, found in tartar of the teeth.

A

Lep'tus Autumnaʼlis. Harvest Bug. Mower's Mite. A parasite that burrows under the skin, causing lesions similar to those of itch.

Le'sion (lado, to hurt). Any injury, hurt or wound in any part of the body. In pathology, any morbid change. L. of Continuity, a division or break in any part that is normally continuous. L. of Nutrition, any pathological alteration in the capillary system, consisting of increase or decrease in the amount of blood required for assimilation and absorption. Le'thal (non, a forgetting). Deadly. Pertaining to or producing death. Leth'argy (Ann). A condition of drowsiness or stupor that cannot be overcome by the will. See, also, Somnambulism. African. See African Lethargy. Let'tuce. See Lactucarium. Leucæ mia. See Leucocythæmia. Leucas'mus, Acquired.

derma.

L.,

See Leuco

Leuchæ mia. See Leucocythemia. Leu'cin (evкóc, white). A crystalline substance probably identical with amidocaproic acid, occurring in the pancreas, spleen, thymus gland and other parts of the body. It is a product of pancreatic digestion.

Leu'co- (Evкos). A Greek prefix signifying white.

Leu'coblast. See Leucocyte.

Leu'cocyte (EVKOG, KUTOG, Cell). The colorless or white corpuscles of the blood, probably derived from the lymph glands, and also from the spleen and marrow. Similar corpuscles are found in many other tissues, and appear thickly wherever inflammation is set up. They are without envelope, and are capable of amoeboid movements. They average about

of

an inch in diameter, but three classes are differentiated: The small, with one or two nuclei, and a small amount of protoplasm; those the size of the red corpuscles; the large amoeboid, with much protoplasm. A phagocytic function has been ascribed to them. They are divided into two kinds, leucoblasts and erythroblasts, the latter transformed into colored blood corpuscles in the spleen and bone marrow. Leucocythæ/mia (2ƐUKOÇ, KUTOs, hollow, aua, the blood). A disease of the bloodmaking organs, characterized by an abnormal increase of the number of white corpuscles, together with enlargement of the spleen, lymphatics, and disease of the medullary substance of the bone. The liver and kidneys are also sometimes involved. The etiology is obscure; the hæmoglobinization of the leucocytes does not take place, and hence the increase of untransformed white corpuscles. Anæmia, breathlessness, muscular lassitude, hemorrhages, retinal and other pain in bones, etc., are the most frequent symptoms. See Charcot-Robin Crystals.

Leucocytogen'esis (UKOÇ, yevvaw, to beget). The formation of white corpuscles in the blood.

Leucocyto'mata (λɛUKOS, KUTOÇ, a hollow). A word used to include all tumors containing cellular growths similar in constitution to the white corpuscles of the blood, such as tubercle, lupus, lepra, etc.

Leucocytosis (λευκός, κυτος). A transient increase in the number of white corpuscles in the blood, not accompanied, as in leucocythæmia, by splenic and glandular enlargement or disease of the bone

marrow.

LEUCODERMA

Leucoder'ma (2ɛvкoç, white, dɛpua, skin). Vitiligo; acquired leucasmus ; leucopathia; piebald skin. An acquired disease marked by the existence and growth of white patches with irregular rounded borders of darker skin. L., Congenital, see Albinism.

Leu'coline. See Chinolina.

Leuco'ma (2εvкоç). An opacity of the cornea the result of an ulcer, wound, or inflammation, and giving it the appearance of ground glass.

Leu'comaïnes (Avкouα, white of egg). "Basic substances found in the living tissues either as the products of fermentative changes or of retrograde metamorphosis." Bouchard and Schär believe they are generated in the intestinal tract and absorbed thence into the system. They are divided into two groups, according to their relations with the analogue chosen as a type: the Uric Acid Group comprises Adenine, Hypoxanthine, Guanine, Xanthine, Heteroxanthine, Paraxanthine, Car

mine, Pseudoxanthine, and Spermine. The Creatinine Group comprises Crusocreatinine, Xanthocreatinine, Amphicreatinine and two unnamed bases. Among yet undetermined leucomaïnes are bases known to exist in expired air, and animal exhalations. The aqueous extract of vapors exhaled by dogs has been found to cause death within 24 hours, when injected into the veins of other animals. The same violent poison is said to produce pulmonary phthisis in confined air by continuous influence. Sewer-air is thought to contain a kindred poison. The leucomaïnes of the saliva are also yet undetermined—though it is known that normal saliva contains several toxic substances, and that the aqueous solution of saliva at 100° poisons or narcotizes birds. The leucomaines of the venom of poisonous snakes are also still undetermined. There are, also, several undetermined leucomaïnes of urine and of animal tissues. The following table is from Vaughan :