Part 65

A*chy"lous (&?;), a. [Gr. &?; without juice.] (Physiol.) Without chyle.

A*chy"mous (&?;), a. [Gr. &?; without juice.] (Physiol.) Without chyme.

||A*cic"u*la (&?;), n.; pl. Aciculæ (&?;). [L., a small needle, dimin. of acus needle.] (Nat. Hist.) One of the needlelike or bristlelike spines or prickles of some animals and plants; also, a needlelike crystal.

A*cic"u*lar (&?;), a. Needle-shaped; slender like a needle or bristle, as some leaves or crystals; also, having sharp points like needles.

A*cic"u*lar*ly, adv..

{ A*cic"u*late (&?;), A*cic"u*la"ted (&?;) } a. (Nat. Hist.) (a) Furnished with aciculæ. (b) Acicular. (c) Marked with fine irregular streaks as if scratched by a needle. Lindley.

A*cic"u*li*form (&?;), a. [L. acicula needle + -form.] Needle-shaped; acicular.

A*cic"u*lite (&?;), n. (Min.) Needle ore. Brande & C.

Ac"id (&?;), a. [L. acidus sour, fr. the root ak to be sharp: cf. F. acide. Cf. Acute.] 1. Sour, sharp, or biting to the taste; tart; having the taste of vinegar: as, acid fruits or liquors. Also fig.: Sour- tempered.

He was stern and his face as acid as ever. A. Trollope.

2. Of or pertaining to an acid; as, acid reaction.

Ac"id, n. 1. A sour substance.

2. (Chem.) One of a class of compounds, generally but not always distinguished by their sour taste, solubility in water, and reddening of vegetable blue or violet colors. They are also characterized by the power of destroying the distinctive properties of alkalies or bases, combining with them to form salts, at the same time losing their own peculiar properties. They all contain hydrogen, united with a more negative element or radical, either alone, or more generally with oxygen, and take their names from this negative element or radical. Those which contain no oxygen are sometimes called hydracids in distinction from the others which are called oxygen acids or oxacids.

In certain cases, sulphur, selenium, or tellurium may take the place of oxygen, and the corresponding compounds are called respectively sulphur acids or sulphacids, selenium acids, or tellurium acids. When the hydrogen of an acid is replaced by a positive element or radical, a salt is formed, and hence acids are sometimes named as salts of hydrogen; as hydrogen nitrate for nitric acid, hydrogen sulphate for sulphuric acid, etc. In the old chemistry the name acid was applied to the oxides of the negative or nonmetallic elements, now sometimes called anhydrides.

A*cid"ic (&?;), a. (Min.) Containing a high percentage of silica; -- opposed to basic.

Ac`id*if"er*ous (&?;), a. [L. acidus sour + -ferous.] Containing or yielding an acid.

A*cid"i*fi`a*ble (&?;), a. Capable of being acidified, or converted into an acid.

Ac`id*if"ic (&?;), a. Producing acidity; converting into an acid. Dana.

A*cid`i*fi*ca"tion (&?;), n. [Cf. F. acidification.] The act or process of acidifying, or changing into an acid.

A*cid"i*fi`er (&?;), n. (Chem.) A simple or compound principle, whose presence is necessary to produce acidity, as oxygen, chlorine, bromine, iodine, etc.

A*cid"i*fy (&?;), v. t. [imp. & p. p. Acidified (&?;); p. pr. & vb. n. Acidifying (&?;).] [L. acidus sour, acid + -fy: cf. F. acidifier.] 1. To make acid; to convert into an acid; as, to acidify sugar.

2. To sour; to imbitter.

His thin existence all acidified into rage. Carlyle.

Ac`id*im"e*ter (&?;), n. [L. acidus acid + -meter.] (Chem.) An instrument for ascertaining the strength of acids. Ure.

Ac`id*im"e*try (&?;), n. [L. acidus acid + -metry.] (Chem.) The measurement of the strength of acids, especially by a chemical process based on the law of chemical combinations, or the fact that, to produce a complete reaction, a certain definite weight of reagent is required. -- Ac`id*i*met"ric*al (&?;), a.

A*cid"i*ty (&?;), n. [L. acidites, fr. acidus: cf. F. acidité. See Acid.] The quality of being sour; sourness; tartness; sharpness to the taste; as, the acidity of lemon juice.

Ac"id*ly (&?;), adv. Sourly; tartly.

Ac"id*ness (&?;), n. Acidity; sourness.