=ACOTYLE′DONS= (-ko-te-lē′-). _Syn._ ACOTYLE′DONES (dŏn-ēz; L., prim. Gr.), Jussieu; ACOTYLÉDONS, Fr.; OHNE SAMENLAPPEN, Ger. In _botany_, plants whose seeds are not furnished with distinct cotyledons or seed-lobes. _Acotyledonous plants_ form one of the two great divisions of the vegetable kingdom, according to the natural system. They are remarkable by increasing chiefly in length, by additions to their end; and not by addition to the outside, as in Exogens; nor to the inside, as in Endogens. They are also termed ASEX′UAL and FLOWERLESS PLANTS, and answer to the CRYPTOGAMIA of the Linnean system. See ACROGENS, CELLULARES, THALLOGENS, &c. =ACOUS′TICS= (-kow′-). The science of audition and sound; that branch of physics which treats of their cause, nature, and phenomena. The doctrine of the production and transmission of sound is termed DIACOUS′TICS; that of reflected sound CATACOUS′TICS. =Acoustics.= In _medicine_, remedies employed to relieve deafness. See DEAFNESS and DROPS, ACOUSTIC. =ACQUETTA.= [IT., _Little Water._] _Syn._ AQUA TOFFANA; A. TOFFANIA; ACQUETTA DI NAPOLI DELLA TOFFANA, IT. A celebrated poison, prepared by an Italian woman named Toffano, or Tophana, and in great request in Rome about the middle of the 17th century. The composition of this poison has been a matter of frequent controversy. Pope Alexander VII, in his proclamation, described it as “aquafortis distilled into arsenic.” This would produce a concentrated solution of arsenic acid. The Emperor Charles VI, who was governor of Naples during Toffano’s trial, declared to his physician, Garelli, that it was arsenic (arsenious acid) dissolved in _aqua cymbalariá_. According to Gerarde this cymbalarià was an aquatic species of pennywort, highly poisonous. The only objection to the latter statement is the smallness of the dose, regard being had to the comparative insolubility of arsenious acid; but if the woman Toffano prepared two poisons, as is probable from history——one, a single dose of which was fatal, and another, of which the dose required repetition, and which was more gradual in its activity——the discrepancy will be at once removed. =AC′RID.= _Syn._ AC′ER, AC′RIS, L.; ACRE (âcre), Fr.; BEISSEND, SCHARF, Ger. In _chemistry_ and _medicine_, sharp, pungent, acrimonious. Acrid substances are such as excite a sensation of pungency and heat when tasted, and which irritate and inflame the skin; as mustard, turpentine, cantharides, &c. =ACRIDITY.= _Syn._ ACRETÉ, Fr.; ACRITUDO, L. The quality of being acrid. =AC′RIMONY.= _Syn._ ACRIMO′NIA, L.; ACRIMONIÉ, ACRETÉ, Fr.; SCHARFE, Ger. In _medicine_ and _chemistry_, the quality or property of inflaming, irritating, corroding, dissolving, or destroying other bodies.