Part 559

2. (Anat. & Physiol.) Pertaining to, or containing, chyle; as, the lacteal vessels.

Lac"te*al, n. (Anat.) One of the lymphatic vessels which convey chyle from the small intestine through the mesenteric glands to the thoracic duct; a chyliferous vessel.

Lac"te*al*ly, adv. Milkily; in the manner of milk.

Lac"te*an (?), a. [See Lacteal.] 1. Milky; consisting of, or resembling, milk. "This lactean whiteness." Moxon.

2. (Anat. & Physiol.) Lacteal; conveying chyle.

Lac"te*ous (?), a. [See Lacteal.] 1. Milky; resembling milk. "The lacteous circle." Sir T. Browne.

2. Lacteal; conveying chyle; as, lacteous vessels.

Lac"te*ous*ly, adv. In a lacteous manner; after the manner of milk.

Lac*tes"cence (?), n. [Cf. F. lactescence.] 1. The state or quality of producing milk, or milklike juice; resemblance to milk; a milky color.

This lactescence does commonly ensue when . . . fair water is suddenly poured upon the solution.

Boyle.

2. (Bot.) The latex of certain plants. See Latex.

Lac*tes"cent (?), a. [L. lactescens, p. pr. of lactescere to turn to milk, incho. fr. lactere to be milky, fr. lac, lactis, milk: cf. F. lactescent.] 1. Having a milky look; becoming milky. [Obs.]

2. (Bot.) Producing milk or a milklike juice or fluid, as the milkweed. See Latex.

Lac"tic (?), a. [L. lac, lactis, milk: cf. F. lactique. See Lacteal, and cf. Galactic.] (Physiol. Chem.) Of or pertaining to milk; procured from sour milk or whey; as, lactic acid; lactic fermentation, etc.

Lactic acid (Physiol. Chem.), a sirupy, colorless fluid, soluble in water, with an intensely sour taste and strong acid reaction. There are at least three isomeric modifications all having the formula C3H6O3. Sarcolactic or paralactic acid occurs chiefly in dead muscle tissue, while ordinary lactic acid results from fermentation. The two acids are alike in having the same constitution (expressed by the name ethylidene lactic acid), but the latter is optically inactive, while sarcolactic acid rotates the plane of polarization to the right. The third acid, ethylene lactic acid, accompanies sarcolactic acid in the juice of flesh, and is optically inactive. -- Lactic ferment, an organized ferment (Bacterium lacticum or lactis), which produces lactic fermentation, decomposing the sugar of milk into carbonic and lactic acids, the latter, of which renders the milk sour, and precipitates the casein, thus giving rise to the so-called spontaneous coagulation of milk. -- Lactic fermentation. See under Fermentation.

Lac"tide (?), n. [Lactic + anhydride.] (Chem.) A white, crystalline substance, obtained from lactic acid by distillation, and regarded as an anhydride; also, by extension, any similar substance.

Lac*tif"er*ous (?), a. [l. lac, lactis, milk + -ferous: cf. F. lactifère.] Bearing or containing milk or a milky fluid; as, the lactiferous vessels, cells, or tissue of various vascular plants.

{ Lac*tif"ic (?), Lac*tif"ic*al (?), } a. [L. lac, lactis, milk + facere to make.] Producing or yielding milk.

Lac"ti*fuge (?), n. [L. lac, lactis, milk + fugare to expel.] (Med.) A medicine to check the secretion of milk, or to dispel a supposed accumulation of milk in any part of the body.

Lac"tim (?), n. [Lactic + imido.] (Chem.) One of a series of anhydrides resembling the lactams, but of an imido type; as, isatine is a lactim. Cf. Lactam.

Lac*tim"ide (?), n. [Lactic + imide.] (Chem.) A white, crystalline substance obtained as an anhydride of alanine, and regarded as an imido derivative of lactic acid.

Lac"tin (?), n. [L. lac, lactis, milk: cf. F. lactine. Cf. Galactin.] (Physiol. Chem.) See Lactose.

Lac`to*a*bu"min (?), n. [L. lac, lactis, milk + E. albumin.] (Physiol. Chem.) The albumin present in milk, apparently identical with ordinary serum albumin. It is distinct from the casein of milk.

Lac`to*bu`ty*rom"e*ter (?), n. [L. lac, lactis, milk + E. butyrometer.] An instrument for determining the amount of butter fat contained in a given sample of milk.

Lac`to*den*sim"e*ter (?), n. [L. lac, lactis, milk + E. densimeter.] A form of hydrometer, specially graduated, for finding the density of milk, and thus discovering whether it has been mixed with water or some of the cream has been removed.

Lac*tom"e*ter (?), n. [L. lac, lactis, milk + meter: cf. F. lactomètre. Cf. Galactometer.] An instrument for estimating the purity or richness of milk, as a measuring glass, a specific gravity bulb, or other apparatus.

Lac"tone (?), n. (Chem.) One of a series of organic compounds, regarded as anhydrides of certain hydroxy acids. In general, they are colorless liquids, having a weak aromatic odor. They are so called because the typical lactone is derived from lactic acid.