Part 54

||A*lex"i*a (?), n. [NL.; a- not + Gr. &?; speech, fr. &?; to speak, confused with L. legere to read.] (Med.) (a) As used by some, inability to read aloud, due to brain disease. (b) More commonly, inability, due to brain disease, to understand written or printed symbols although they can be seen, as in case of word blindness.

{ ||Al*fil`e*ri"a , ||Al*fil`e*ril"la } (?), n. [Mex. Sp., fr. Sp. alfiler pin.] Same as Alfilaria.

||Al*for"ja (?), n. [Also alfarga, alforge.] [Sp.] A saddlebag. [Sp. Amer.]

Al"gin (?), n. (Chem.) A nitrogenous substance resembling gelatin, obtained from certain algæ.

Al*gom"e*ter (?), n. [Gr. &?; pain + -meter.] (Psychol.) An instrument for measuring sensations of pain due to pressure. It has a piston rod with a blunted tip which is pressed against the skin. -- Al*gom"e*try (#), n. -- Al`go*met"ric (#), *met"ric*al (#), a. -- Al`go*met"ric*al*ly, adv.

Al*gon"ki*an (?), a. 1. Var. of Algonquian.

2. (Geol.) Pertaining to or designating a period or era recognized by the United States Geological Survey and some other authorities, between the Archæan and the Paleozoic, from both of which it is generally separated in the record by unconformities. Algonkian rocks are both sedimentary and igneous. Although fossils are rare, life certainly existed in this period. -- n. The Algonkian period or era, or system or group of systems.

Al*gon"qui*an (?), a. Pertaining to or designating the most extensive of the linguistic families of North American Indians, their territory formerly including practically all of Canada east of the 115th meridian and south of Hudson's Bay and the part of the United States east of the Mississippi and north of Tennessee and Virginia, with the exception of the territory occupied by the northern Iroquoian tribes. There are nearly 100,000 Indians of the Algonquian tribes, of which the strongest are the Ojibwas (Chippewas), Ottawas, Crees, Algonquins, Micmacs, and Blackfeet. -- n. An Algonquian Indian.

Al`i*phat"ic (?), a. [Gr. &?;, &?;, oil, fat.] (Org. Chem.) Of, pertaining to, or derived from, fat; fatty; -- applied to compounds having an openc-hain structure. The aliphatic compounds thus include not only the fatty acids and other derivatives of the paraffin hydrocarbons, but also unsaturated compounds, as the ethylene and acetylene series.

Al"ka*li (?), n. Soluble mineral matter, other than common salt, contained in soils of natural waters. [Western U. S.]

Alkali flat. A sterile plain, containing an excess of alkali, at the bottom of an undrained basin in an arid region; a playa.

Alkali soil. Any one of various soils found in arid and semiarid regions, containing an unusual amount of soluble mineral salts which effloresce in the form of a powder or crust (usually white) in dry weather following rains or irrigation. The basis of these salts is mainly soda with a smaller amount of potash, and usually a little lime and magnesia. Two main classes of alkali are commonly distinguished: black alkali, which may be any alkaline carbonate, but which practically consists of sodium carbonate (sal soda), which is highly corrosive and destructive to vegetation; and white alkali, characterized by the presence of sodium sulphate (Glauber's salt), which is less injurious to vegetation. Black alkali is so called because water containing it dissolves humus, forming a dark-colored solution which, when it collects in puddles and evaporates, produces characteristic black spots.

Alkali waste. Waste material from the manufacture of alkali; specif., soda waste.

Al`le*ghe"ni*an (?), a. Also Al`le*gha"ni*an. (Biogeography) Pertaining to or designating the humid division of the Transition zone extending across the northern United States from New England to eastern Dakota, and including also most of Pennsylvania and the mountainous region as far south as northern Georgia.

Al"le*ghe`ny (?), a. 1. Of or pertaining to the Allegheny Mountains, or the region where they are situated. Also Al"le*gha`ny.

2. [From the Allegheny River, Pennsylvania.] (Geol.) Pertaining to or designating a subdivision of the Pennsylvanian coal measure.

Al*le"lo*morph (?), n. [Gr. &?; of one another + Gr. &?; form.] (Biol.) One of the pure unit characters commonly existing singly or in pairs in the germ cells of Mendelian hybrids, and exhibited in varying proportion among the organisms themselves. Allelomorphs which under certain circumstances are themselves compound are called hypallelomorphs. See Mendel's law. -- Al*le`lo*mor"phic (#), a.

As we know that the several unit characters are of such a nature that any one of them is capable of independently displacing or being displaced by one or more alternative characters taken singly, we may recognize this fact by naming such characters allelomorphs.

Bateson.

Al"li*ga`tor wrench. (Mech.) A kind of pipe wrench having a flaring jaw with teeth on one side.

Al`lo*troph"ic (?), a. [Gr. &?; other + trophic.] (a) (Physiol.) Changed or modified in nutritive power by the process of digestion. (b) (Plant Physiol.) Dependent upon other organisms for nutrition; heterotrophic; -- said of plants unable to perform photosynthesis, as all saprophytes; -- opposed to autotrophic.

Al"loy steel. Any steel containing a notable quantity of some other metal alloyed with the iron, usually chromium, nickel, manganese, tungsten, or vanadium.

Al*lu"vi*al (?), n. Alluvial soil; specif., in Australia, gold-bearing alluvial soil.

Al"pen*glow` (?), n. A reddish glow seen near sunset or sunrise on the summits of mountains; specif., a reillumination sometimes observed after the summits have passed into shadow, supposed to be due to a curving downward (refraction) of the light rays from the west resulting from the cooling of the air.

{ Al"pen*horn` (?), Alp"horn` }, n. [G. Alpenhorn.] A curved wooden horn about three feet long, with a cupped mouthpiece and a bell, used by the Swiss to sound the ranz des vaches and other melodies. Its notes are open harmonics of the tube.

Al*pes"trine (?), a. (Bot.) Growing on the elevated parts of mountains, but not above the timbe&?; line; subalpine.

Al"pha pa"per. (Photog.) A sensitized paper for obtaining positives by artificial light. It is coated with gelatin containing silver bromide and chloride. [Eng.]

Alpha rays. (Physics & Chem.) Rays of relatively low penetrating power emitted by radium and other radioactive substances, and shown to consist of positively charged particles (perhaps particles of helium) having enormous velocities but small masses. They are slightly deflected by a strong magnetic or electric field.