Page:Cyclopaedia, Chambers - Supplement, Volume 1.djvu/228

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■we find defcriptions given by Oribafius, iElius, and ^igineta. V. Gorr. Def. Med. p. 8. a. ATHANASIA, ABe^a^a, among the antient phyficians, an epithet given to a kind of antedotes, fuppofed to have the power of prolonging life, even to immortality. V. Gorr. Med. Def. p. 8. a.

In the Auguftan difpenfatory we ftill find a medicine under the Appellation of Athanafia Magna, commended againft dyfen- teries and haemorrhages. Brun. Lex. Med. p. 88. a.

Athanasia, in botany, is ufed in fome authors for tanzy. Ger. Em. Ind. 2.

ATHENATORIUM, among chemifts, a thick glafs cover, placed on a cucurbit, having a flender umbo, or prominent part, which enters like a ffopple, within the neck of the cu- curbit. Brun. Lex. Med. p. 88. b.

ATHENIPPUM, ASmiOTo., in the antient phyfic, a collyrium, commended againft divers difeafes of the eyes ; thus deno- minated from its inventor Athenippus. GVr.Def. Med. p. 8. b. Its defcription is given by Scribonius Largus, and by Gorrzeus after him. Ubifupra.

Galen mentions another Athenipputn, of a different compofi- tion, by which it appears, this was a denomination common to feveral collyriums.

ATHERINA, in ichthyography, a name given by Rondeletius, and fome other authors, to the Hepfetus, or Anguella, a fmall fifh, common on the fhores of the Mediterranean ; but by Bellonius appropriated to a fifh of a different genus. JPil- lughby, Hilt. Pif. p. 209.

The Atherina of this laft author is a fmall fifh of the length and thicknefs of a finger, of a fine white colour, and, when held up againft the light, as tranfparent as glafs ; its eyes are large, and its finns are placed two on the fides, two in the middle of the belly, and only one on the back, which is thin, and very (lender. In this particular it remarkably differs from the hepfetus, which has two back fins. Bellonius, de Pifcib.

ATHLETIC (C>/.)— Athletic Habit, ABfcfci I|is, de- notes a ftrong hale conftitution of body. Antiently itiignified a full, flefhy, corpulent ftate, fuch as the Athletes endeavoured to arrive at. Gor. Med. Def. p. 8. b. The Athletic habit is efteemed the higheft pitch of health ; yet is it dangerous, and the next door to difeafe ; fince when the body is no longer capable of being improved, the next altera- tion muft be for the worfe. Burggr. Lex. Med. p. 1 1 79. a Brun. Lex. Med. p. 88. b.

The chief object of the Athletic diet, was to obtain a firm, bulky, weighty body, by force of which, more than art and agility a, they frequently overpowered their antagonift : Hence they fed altogether on dry, folid, and vifcous meats. In the earlier days, their chief food was dry figs, and cheefe, which was called Arida Saginatio ^p rpnip*, and Affxwtj ha%v[av itrx*3°» ; Oribafius, or, as others fay, Pythagoras, firft brought this in difufe, and fubftituted flefh in lieu thereof. 1 hey had a peculiar bread, called xoMvue : They exercifed, cat and drank without ceafrng : They were not allowed to leave off eating, when fatiated, but were obliged to cram on till they could hold no more: By which means they at length acquired a degree of voracity, which, to us, feems incredi- ble, and a ftrength proportional '. Witnefs what Paufanius relates of the four celebrated athlete, Polydamus the Theffa- lian, Milo the Crotonian, Theagenes the Thafian, and Eu- thymus the Locrian : The fecond is faid to have carried a bull on his back a confiderable way, then to have knocked him down with a blow of his fift, and laftly, as fome add, de- voured him at a meal b. — [ 3 V. Gorr. loc. cit. Burggr. Lex. Med. T, 1. p. ny 7. Pitifc. Lex. Ant. T. 1. p. 197.
 * Dan. Diet. Ant. in voc]

Athletic Weight. See the article Weight.

ATHLOTHETA, aMiI*, in antiquity, an officer ap- pointed to fuperintend the public games, and adjudge the prizes. Pott. ArchDeol. 1.2. c. 21.

'I he Athhtheta was the fame with what was otherwife called Mfymneta, Brabeuta, Agonarcba, Agonotheta, &c.

ATINGA guacu mucu, in zoology, the name of a Brafilian bird of the ftarling kind. It refemblts the thrufh in fize. Its head is very large and thick, and its neck long. Its tail is very remarkably long, being no lefs than nine fingers breadth in length, and is compofed of ten feathers. Its head, neck, back, wings, and tail, are all of a dqfky blaekifh brown ; its tail darker than the reft, but the ends of all the tail-feathers are white, or of a mixture of brown and white ; the throar, breaft, and belly, are grey, and on its head it has two ranges of long feathers, which it can raife at pleafure into a fort of double creft, or two horns. Marggrave's Hift. Brafil. See Tab. of Birds, N°. 31.

ATIZOE, in the writings of the antient naturalifts, a name of a ftone ufed in the confecration and anointing of kings. Pliny defcribes it to have been of a lenticular figure, and of the fize of three fingers, of a bright filvery colour, and of a pleafant finell. He fays it was found in India, and in fome other places. Agricola is of opinion, it was a kind of bitu- men.

ATLAN TIDES, in aftronomy, a denomination given to the Pleiades, or feven ftars, fometimes alfo called Vergilix. They are thus called, as being fuppofed by the poets to have been |

the daughters either of Atlas, or his brother Hefperus, who were trandated into heaven. Fab. Thef. p. 284..

ATLANTIS (Cycl.) — New Atlantis is the name of a fictitious, philofophical commonwealth, of which a defcription has been given by lord Bacon.

The new Atlantis is fuppofed to be an ifland in the South Sea, to which the author was driven, in a voyage from Peru to Japan. The compofition is an ingenious fable", formed after the manner of the Utopia of Sir Thomas More, or Campa- nalla's city of the fun. Its chief defign is to exhihit a model or defcription of a college, inftituted for the interpretation of nature, and the production of great and marvellous works, for the benefit of men, under the name of Solomon's houfe, or the college of the fix days work. Thus much, at Ieaft, is finifhed ; and with great beauty and magnificence. The au- thor propofed alio a frame of laws, or of the beft ftate or mould of a commonwealth. But this part is not executed b . — [" V. Pref. to Atlan. ap. Bac. Work. T. 3. p. 235! b Shav. Bibl. Phil. c. 7. §. 14. p. 291. Pafch. de Var. Mod. Mor. trad. c. 2. p. 214.

ATMOSPHERE [Cycl.)— Galileo, having obferved that there was a certain ftandard altitude, beyond which no water could be elevated by pumping, took an occafion from thence to call in queftion the doctrine of the fchools, which afcribed the afcent of water in pumps, to the fuga vacui, and in the room thereof he happily fubftituted the hypothefis of the air's pief- fure and gravitation. It was to him, indeed, little better than an hypothefis, fince it had not then thefc confirmations from experiments, which were afterwards found out by his fcholar' Torricellius, and other fucceeding philofophers, particularly Mr. Boyle.

The gravity and preffure of the air is clearly proved by the Torricellian experiment"; and was further confirmed by Monficur Pafcal's imitation of that experiment with water b . Other experiments have alio been made, with fluids varioufly combined ■ . — [ > V. the article Air, Cycl. b See Cotes, Hydroft. Left. VIII. = Ibid.

Mr. Cotes has given us a computation of the weight of all the air which preffes upon the whole furface of the earth. He finds this weight to be equal to that of a globe of lead of fixty miles diameter. The computation proceeds on thefe principles : That the weight of a column of air, reaching to the top of the Atmojphere, is moft commonly equal to a column of water, having the fame bafis, and the altitude of 34 feet ; that the femi-diameter of the earth is equal to 20,949,655 feet ; and that the fpecific gravity of water is to that of lead as 1000 to 11,325. Cotes, Hydroft. Left. p. 112, 113. No one has yet been able to determine, how far the air may admit of condenfation and rarefaction. It is, however, cer- tain, that there are, in nature, fome limits which cannot be exceeded. No condenfation can reach fo far as to caufe a pe- netration of parts; and if the rarefaftion of the air be ftill greater, as its diftance from the furface of the earth increafes, its fpring will be at length fo weakened, that the force which every particle of it endeavours to tend upwards, from the par- ticles which are next below it, will be weaker than the force of its own gravity, which endeavours conftantly to detain it. The rarefaftion of the air muft be therefore bounded, where thefe two oppofite forces come to balance each other. But though it be certainly true, that the air cannot poffibly expand itfelf beyond a certain meafure, on account of its gravity, yet, fince men have not hitherto been able to fet any bounds to its utmoft expanfion, it is equally certain, that we cannot define the limits of the Atmofphere.

Yet we may coileft how much the air is rarified, at any propofed altitude from the furface of the earth : For if any number of diftances from the furface of the earth be taken in an arithmetical progreffion, the denfities of the air, at thofe diftances, will be in a geometrical progreffion : And as, the rarity of any body is reciprocally as its denfity, it follows, that as the diftances from the furface of the earth do increafe in an arithmetical progreffion, fo do the different degrees of rarity in the air increafe in a geometrical progreffion. See Coles's Hydroft. Left. p. 119— 122. where he proves this in a very eafy manner, and in a method intelligible to thofe who are not acquainted with the properties of the hy- perbola, and logarithmic curve made ufe of by Dr. Halley, and Dr. Gregory, in their reafonings on this fubjeft. From hence it may be determined how much the air is rarified at any propofed elevation from the earth's furface : For the ele- vation will be every where proportionable to the logarithm of the rarity. If then, by experiment, we can find the rarity of the air at any one elevation, we may, by the rule of propor- tion, find what is the rarity at any other propofed eleva- tion, by faying, as the elevation at which the experiment was made, is to the elevation propofed, fo is the logarithm of the air's rarity, which was obferved at the elevation where the experiment was made, to the logarithm of the air's rarity at the elevation propofed.

By Monfieur Pafcal's experiment [at the Puy de Dome, and by Mr. Cafwell's, made upon Snowden-Hill, it appears, that at the altitude of 7 miles, the air is about 4 times rarer than at the furface of the earth. Hence it follows, that at the alti- tude of 14 miles, the air is 16 times rarer than at the furface; 1 and