

LAUGH 



Sydenham's. Synonym of Vinum opii. L., War- 

 ner's, an ammoniated tincture of opium. Unof. 



Laugh {lahf) [ME., laughen, to laugh]. I. To make 

 an audible expression of mirth. 2. The audible expres- 

 sion of mirth. L., Canine, L., Sardonic. Synonyms 

 of Risus sardonicus, q. v. 



Laughing, or Laughter (lahf'-ing, lahf'-ter) [ME., 

 laughen, to laugh]. A succession of rhythmic, spas- 

 modic expirations with open glottis and vibration of the 

 vocal bands. L. Gas, nitrous oxid, or protoxid of 

 nitrogen. See Nitrotis Oxid and Anesthetics. L. 

 Muscle, the risorius. See Muscles, Table of. 



Laugier's Hernia. See Hernia and Diseases, Table of. 



Laumonier's Ganglion. The superior carotid gan- 

 glion. 



Laurel {law' -r el, lor' -el) [taunts']. See Cherry-laurel, 

 California Laurel, Great Laurel, Kalmia, Laurus. 

 L. -water, aqua laurocerasi. See Chert y-laurel. 



Laurer, Canal of. See Canal. 



Laurin (law'-rin) [laurus, laurel], C^HjoOj. A fatty, 

 crvstallizable substance obtainable from the berries of 

 the European laurel, Laurus nobilis. 



Lauro-cerasus (law-ro-ser' '-as-us) [laurus, laurel ; 

 isus, cherry-tree]. See Cherry-laurel. Lauro- 

 cerasi folia, the leaves of the European cherry-laurel. 



Laurus (law'-rus) [L.]. A genus of old-world trees 

 and shrubs; the true laurels. Formerly the plants 

 that produce benzoin, camphor, cassia, cinnamon, etc., 

 were assigned to this genus, but at present it is much 

 restricted by botanists. L. nobilis, the noble laurel, is 

 indigenous in the south of Europe. Its fragrant oils 

 (one essential, from the leaves, and the other fixed, 

 from the berries) are chiefly used in liniments. Unof. 



Lauryl (law'-ril) [laurus, laurel], C 12 H. i3 . A univa- 

 lent radicle, the hydrid of which is dodecane. 



Laurylene (law' -ril-en) [laurus, laurel], C,,H 24 . A 

 liquid with a high boiling-point, found in certain 

 mineral oils. 



Lauth's Ligament. See Ligament. L.'s Violet. 

 See Pigments. Conspectus of. 



Lava (lah'-vah) [L. , a flood or torrent]. The molten 

 ejecta of a volcano. 



Lavage (lav-ahzh') [Fr.]. Irrigation or washing out of 

 an organ, such as the stomach, the bowel, etc. 



Lavamentum (lav-am-en' -turn) [lavare, to wash]. An 

 injection. 



Lavandula (lav-an'-du-lah). See Lavender. 



Lavater, Angle of. See Angle. 



Lavatera (hiv-at-e'-rah) [after the two Lavaters, phy- 

 sicians of Zurich]. A genus of malvaceous trees, 

 shrubs, and herbs, natives of the old world. L. 

 thuringiaca, L. triloba, and others abound in 

 mucilage, and are used as demulcent remedies. Unof. 



Lavation (lav-a'-shun) [lavatio, from lavere, to wash]. 

 Lavage. L. of the Blood, intravenous injection of 

 water. 



Lavatory (lav'-at-or-e) [lavatorium, a place for bathing], 

 A wash or lotion for a diseased part. 



Lave (lav) [lavare, to wash]. To wash; bathe. 



Lavel (la'-vel) [Prov. Eng.]. A local name for the 

 epiglottis. 



Lavement (laiZ-ment) [lavare, to wash]. I. Awash; 

 the act of washing. 2. A clyster or enema. 



Lavender (lav'-en-der) [lavare, to wash] . The flowers 

 of Lavandula vera, having properties due to a volatile 

 oil. It is aromatic, stimulant, and carminative, but is 

 used mainly as a flavor and as an adjuvant to other medi- 

 cines. Lavandulae, Ol., the volatile oil distilled 

 from the whole herb. Dose rr\j-v. L., Ol., Flo- 

 rum, the oil distilled from the fresh flowers ; prefer- 

 able to the preceding. Dose n\j-v. A constituent 

 of Spt. odoratus. L., Spirit of, 5 parts of the oil 



663 LAW 



in 95 of alcohol; a perfume. Dose sjss-j. ***» 

 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 gss-ij. A constituent of Fowler's solution. 

 To the labiate genus Lavandula also belong L. spica, 

 or broad lavender (which furnishes the oil of spike), 

 and other medicinal species. 



Laveran's Corpuscles, or Plasmodia. The Plas- 

 modia malaria, first described by Laveran as Os- 

 cillaria malaria-. See Parasites (Animal), TabU of, 

 and Plasmodium. 



Laville's Liquid Mixture, or Antigout Remedy. A 

 mixture used in acute rheumatism. It is said to be a 

 tincture of quinin and colocynthin, but very prob- 

 ably the active principle in it is colocynthin. See 

 Colocynthis . 



Lavipedium (lav-ip-e'-de-um) [lavare, to wash ; pes, 

 foot]. A foot-bath ; a pediluvium. 



Law (/aw) [ME., lawe, a law]. A generalized and 

 epitomized statement of facts. A general rule, or 

 constant mode of action of forces, or phenomena. A 

 rule of action prescribed by authority. See Jurispru- 

 dence. L. of Abridged Transmission, the forms 

 assumed by an individual in its ontogeny differ some- 

 what from the accepted ancestral type. L. of Adap- 

 tation, the law that a living organism, under whatso- 

 ever conditions, will mould itself into harmony with 

 those conditions, and thus continue its existence, 

 whether in a more perfect or less perfect form. L., 

 Angstrom's, of Absorption-spectra, the " rays that 

 a substance absorbs are precisely those that it emits 

 when made self-luminous." L., Ampere's. See 

 Ampere. L. of Avogadro, equal volumes of all gases 

 and vapors, at like temperature and like pressure, con- 

 tain an equal number of molecules. L., Baer's, the 

 principle that the evolution of any animal form is 

 determined, first, by increasing histologic and morpho- 

 logic differentiation, and secondly, by transition from a 

 more general to a more specific type. L., Bell's, the 

 law that the ventral roots of the spinal nerves are 

 motor, and the dorsal sensory. See also Wallerian 

 Degeneration. L., Berthollet's, when two salts in 

 solution can by double decomposition produce a salt 

 less soluble than either, this salt will be produced. 

 L., Boudin's, that antagonism exists between tuber- 

 culosis and malaria. L., Boyle's, at any given 

 temperature the volume of a given mass of gas varies 

 inversely to the pressure that it bears. This is also 

 called Mariotte's Law. L., Brewster's, the angle of 

 polarization of a body is equal to that angle of incidence 

 at which the reflected rays are at right angles to 

 those refracted. L., Charles's, equal increments 

 of temperature add equal amounts to the product of 

 the volume and pressure of a given mass of gas. The 

 increase is ^i-j of its volume measured at — 273 C, 

 which is the zero of absolute temperature. L., 

 Colles', a child born of a mother who is without ob- 

 vious venereal symptoms, and which, without being ex- 

 posed to any infection subsequent to its birth, presents 

 symptoms of syphilis when a few weeks old, can infect 

 the most healthy nurse, whether she suckle it or merely 

 handle and dress it, while it will not infect its own 

 mother, even though she suckle it while it has venereal 

 ulcers of the lips and tongue. L. of Contemporane- 

 ous Transmission, changes in an individual appear 

 at the same time as they appeared in its ancestor. L., 

 Coulomb's, the force of attraction or repulsion between 

 two charges of electricity is proportional to the quantity 

 of electricity acting, and inversely proportional to the 

 square of the distance between them. L., Dalton's, 

 or L., Dalton-Henry's, although the volume of a gas 



