AC IT

A 01

Vii< master proof; alluding to the strength ;md importance of Achil-les among the Greeks.

AC Ill LI AN I, Alexander, born at Bologna, and professor ofphilosophy in that university, flourished in. tin- ljthand Kith cen-turies. lie published several pieces on philosophical subjects,dedicated to Bentivopli. 1

AcKiu.ifn, C laudius, grandson of the former, read lectures atBologna, Feirara, and Banna: where he was much esteemed asa philosopher, a divine, a lawyer, an orator, a mathematician,and a poet. He published a volume of Latin Letters, and ano-iher or Kalian poems which gained him great reputation: hedied m 1640, aged 66.

ALIlILl.Ib TF.N DO, in anatomy, is a strong tendinous cord,formed by the union of the tendons of the 4 extensor muscles ofthe tool, and inserted into the os calcis. It has its name from theratal wound Achilles is said to have received in that part, from Pa-ris tiie son of Priam .

ACI1I011L, or ACIIIOTF, a foreign drug, used in dying,and in the preparation of chocolate.

ACH1VI, the Greeks, so called by the Bomnn peels.

AG HLY'S, in mythology, the first being, who existed before thecreation of the world, of chaos, and of the gods.

ACHM.hr, the son of Seeriin, lived in the i)th century, and

ujisidicu inn. oi ci reels, raw i.aun ov i,eo y use us, mi my.ACHMETSC11KT, a town of Cvim Turtary, _m the Russianprovince of Taurida , and government of Catharmenslaf. _ >sthe resilience of the Sultan (lulga, eldest son ot the Khan of 1 ai-fttrv. Lon. 33. 20 . E. Lat. 45. 0. N. ,

ACHM1M, a large town of bpper Egypt , situated on theeastern bank of the Nile .

ACIIONHY, a small town of Ireland , seated on the Shannon,in the county of Sligo, and province of Connaught .

ACIIOIL a valley of Jericho, near Gilgal.

Achor, in medicine, the third species of tinea, or scald-head.

Achor, in mythology, ‘-lie god of flies.

_ AC H RADI NA, in ancient geography, one of the four divi-sions of Syracuse .

ALMIRAS, or SAPOTA PLUM: a genus of the monogyniaorder, and hexaudria class of plants; and in the natural order l)u-mos:e. M'he characters are: calyx a peviauthium; leaflets six, o-sate, concave, erect; corolla one ovate petal, the height of the< anther® acute; gernun roundish, depressed; stylus subu-

lated, and longer tlum the corolla; stigma obtuse; periearpimnglobular twelve-celled; seeds solitary, ovate, and glossy, 'thereare 3 species.

ACHROMATIC, [Gr. of «, privative, and xc lu i u “> colour,']in epithet expressing want of colour.

Achromatic telescopes, are telescopes contrived to remedythe aberrations in colours; See Telescope and Optics.ACItRCNICAL, See Acroxych.u..

AGIISU APil, a citv, originally a kingdom, near the foot of■mount M’ahov, taken by'Joshua.

ACH t F.LIN'G, a measure for liquids used inGc manv, 3'.’achtelings make a heemer; 4 sciltims or sciltins, make an ach-teung,

AC II I LN'DLl-.I.tXG a measure for in-ain. used in someparts ot Holland . °

w-l! s l ,eries Cassia, that grows in Arabia.

ACri i R, a strong tow n aiul castle of the Ukrain , subject tothe Russians since 1067. it is 127 miles F.. of Flow, Lon. 36. 10.E. I .at. 49. 32. N.

... .n.-vtmai, surrounding the ger-

mop, bearded at the top, concave and falling off; anther® ovate,incumbent; stylus iiiii'orm, the length of the stamina; capsuleroundi-h one-ceUed, not: gaping; seed single and oblong. Ot thisgenus 16 species are enumerated; all natives of the Indies andAfrica . Only one of them, the amarantlnis, is commonly culti-vated in botanical gardens.

ACJlYROPHOivUS, in botany, See IIypociiterjs.

ACICOCA, an herb that grows in Perth and is sometimesused instead of the herb paraguui, of which it is said to have allthe properties.

ACK'UL.F,, the small pikes or prickles of the hedge-nog, e-chinus mariiuis, Ac.

ACIDALIUS, Yaleirt, an eminent critic of the loth century,born at Whitstock, in Brandenburgb. M huamis says, that his ex-cessive application to study and his sitting up at night, to com-pose his conjectures on Phuitus, brought upon him a distemper,which carried him off in three days, on the 25th May, aged2S. lie wrote a Commentary on Quintus Curtins; Notes onTacitus , on the. twelve Panegyrics; besides speeches, letters, an;lpoems, which last are inserted in the DcliciiC of the German poets.

ACIDALUS, the name of a fountain in Orchomenos, a city of Boetia, in which the Graces who are sacred to \ enus, bathed.Hence Virgil, Kn. lib. i. 1. 724, calls the queen of beauty Aeiilalia,ACID1FIABLE hast' or radical, any substance capableof uniting with oxygen, so as to tonn with it an acid: hence itdetermines the species of the acid : thus, sulphur combined witha sufficient dose of oxygen forms sulphuric acid.

ACIDOTON, a genus of the Monoecia Polyandria class andorder; it: has male and female flowers on the same, or a diffluenttree. ■ There is but one species, the A. ureas, a native of Jamaica ,which ri-cs eight or nine feet.

ACIDS , [ticcrc, to be sharp, Lai.] originally the same withsour, and applied to all substances having that taste. M ho term isnow much move comprehensive, and includes an extensive classof suits, which have all or most of the following properties. 1. Theyhave a sour or sourish taste. 2. M'hey change the blue coloursof vegetables to a red. M’he tincture of litmus, and syrup ofviolets or radishes are the vegetable blues generally employedto didinguish this property, and hence are called tests or reagents.

If these colours have been previously converted to a green by al-kalies, the acids restore them again. 3. M'hev unite with waterin almost any proportion. 4. 'l'hey combine with ali the. alkalies,and most of the metallic oxydes and earths; the compounds aresails. Acids are the most important class of bodies subjected tochemical research, and the foundation of modern chemistry lieschiefly in the attention paid Io these substances, and their use in theexamination of other bodies. Paracelsus believed there was onlvone acid principle in nature, which, according to Beecher, was acompound of earth and water, and btalil endeavoured to prove,that this compound is sulphuric acid, and that all other acids arcformed by a combination of this with other substances. However,the discoveries of Bergman, Schoele, and Lavoi-ier, demonstratedthe falsehood of this theory, by shewing that sulphuric acid doesnot exist in the other acids, and that this is not composed of earthand water, hilt of sulphur and oxygen. Mr. Lavoisier , foundthat several combustible substances combined with oxygen formacids; that acids generally contain oxygen; and that when theoxygen is separated they lose their acidity. From this he con-cluded that the acidifying principle is oxygen; and hence that acidsare oxygen united with some combustible substance as the base;which therefore determines the characteristic properties, or thespecies of the acid. M'his conclusion, as far as regards the greaternumber of acids, is certainly true. All the simple combustibles,except hydrogen, art* convertible into acids; and these acids arecomposed of oxygen and the combustible body combined. Thisis the case also with four of the metals. It mint not, however, headmitted without some limitation. 1. W hen it is said that oxygeais the acidifying principle, it is not meant to aflirm that oxygenpossesses the properties of an acid, which would be contrary totruth; all Unit can he meant is, that it enters as a component partinto acids, or that acids contain it as an essential ingredient. 2. But,even in this sense, the assertion cannot be admitted: for it is nottrue that oxygen is an essential ingredient in all acids, or that nobody possesses the properties of an acid unless it contains oxygen.Sulphurated hydrogen, for instance, possesses ail the characters ofan acid, yet it contains no oxygen. 3. When it is said that oxy-gen is the acidifying principle, it cannot he meant to aflirm thatthe combination of oxygen with bodies produces in all cases anacid, or that whenever a body is combined with oxygen the productis an acid; for the contrary is known to every chemist. Hydro-gen, for instance, when combined with oxygAi, forms not an acid,but pure water, and the greater number of metallic bodies formonly oxydes. All that can be meant, then, when it is said that

oxygen