acid

(as'id) [L. acid us, sour.] i. of an electronegative element or radical with hydrogen; it forms salts by replacing all or part of the hydrogen with an electropositive element or radical. An acid containing one displaceable atom of hydrogen in the molecule is called monobasic; one containing two such atoms, bibasic; and one containing more than two, polybasic. 2. In popular language, any chemical compound which has a sour taste. 3. Sour, sharp to the taste.- 4. Relating to an acid; giving an acid reaction, turning a vegetable blue red. (For definitions of the different acids, see the adjectives or under acidum; the acids official in the U.S. and Br. Pharmacopeias are defined under acidum.) a.-albu'min, syntonin; a derived albumin formed by the action of a dilute acid on a native albumin; it is not coagulable by heat, and is precipitated by neutralization of the solution. a.-fast, a term denoting bacteria which are not decolorized by mineral acids after having been stained with aniline dyes; the leprosy, smegma, tubercle, and hay bacilli are examples of acid-fast bacilli, a.-gland, one of the stomach glands secreting the acid of the gastric juice. a.-intozica'tion, a pathological state due to the toxic effect of an exce of acids formed within the organism or introduced from without, a.- proof, a.-fast.