Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/815

 ZYG

There are tontrapunto alia zoppa fopra U fogette, as well as fotto UfogettC) t. e, above and below the fubject. See the ar- ticle So get to. ZORABA, a word ufed by fome of the chemical writers to ex-

prefs vitriol. ZOSTER, a word ufed by fome to exprefs that kind of herpes, called by others zona and zingiHa, and by us ufually known under the name of the foixgles. ZOTHECA, among the antients, the place where the animals

dcfigned for facrifice were kept. Pitijc. in voc ZOZONIS1US, in natural hiftory, a name of one of the gems of the antients, but of which our accounts are fo fhort, that we can make no conjecture of what it was. Pliny only tells us, that it was found in the river Indus, and ufed by the magi,

ZLTFOLO, in the Italian raufic, a little flute or flagelet, having a very flirill found, like the whiffling of fmall birds. Broffard, ZURNAPA, in zoology, the Arabian name of an animal of a very lingular kind, and feeming properly to belong to no known genus of animals, but to be perfectly fill generis. It is alfo called camekparddh by Latin authors, and geraffa by eaftern nations.

It is not certainly known whether it chews the cud or not ; but as its hoofs are cloven, and it has horns on its forehead, and wants the fore-teeth in its upper jaw, and feeds on vege- tables, it is probable that it does.

It is a lingular, elegant, and beautiful creature, and is very re- markably tame and tractable, even fcarce lefs fo than a fheep, and feefns intended by nature for a domeftic, not a favage ani- mal. Its head is wholly of the make of the flag's, but differs in fize, and has two little obtufe horns, which are not more than fix fingers breadth long, and are hairy : the male and fe- male both have thefe, and the latter is diftinguifhed by having them fhorter than the former. Its ears are larger, and like thofe of the ox-kind ; its tongue is alfo like that of an ox, and it wants the fore-teeth in the upper jaw. Its neck is remark- ably long, ftrait, and fiender, in a grown animal. The neck is ufually (even feet long, and the meafure from the tail to the top of the head eighteen feet ; and when it ftands erect, its head is fixteen foot from the ground; it has a fmall mane ; its legs are very (lender, and the forelegs very long ; the hinder ones very fhort, fo that the creature feems always to Hand upright.

Its hoofs are cloven exactly as thofe of the ox, its tail reaches down to its hams, and is rounded and covered with vcty thick hairs; the middle of its body is flehder ; it is very like the camel in all its natural properties : when it runs it holds the two forefeet together, it lies down on the belly, and claps its neck down on the thighs and breaft in the manner of the camel. As it ftands it can fcarce reach to eat the grafs, un- lefs its fore-legs are very far expanded, and that is a pofture of great pain to it ; fo that nature feems to have allotted it to feed in its wild ftate on the leaves bf trees, which its long neck will very well enable it to get at. It is very beautifully fpotted all over its body in the manner of the leopard. The velvety covering of its horns feems to make it of the flag kind, but its fhape is wholly different from thofe of that ge- nus. Bellon. Obf. 1. 2. c. 49. ZYG./ENA, in zoology, the name of a fifh of the fharkkind, called in Englifli the ballance fijb^ or the hammer-beaded jhark. See Tab. of Fifties, N°. 2.

It is an extremely lingular and remarkable fifti, and differs not only from all the other marks, but from all the fifh in the world in the figure of its head : this is not placed, as in all other fiflies, longitudinally, or in a line with the body, but is fet on tranf- verfely as the head of a hammer or mallet upon the handle. This is femicircular at the front, and runs to fo thin and fharp an edge, that as the fifh fwims forward with violence, it may cut other fifties, and is terminated at each end by an eye ; thefe arc very large, and fo placed, that they more conveni- ently look down than either upward or fideway. In the far- ther part of the forehead alfo, near the eyes, on each fide there is a large oblong foramen, ferving either for hearing or fmelling, or perhaps for both. The mouth is very large, and placed under the head, and armed with four rows of extreme- ly fharp and ftrong teeth, flat, and ferrated at their edges. The tail is compofcd of two fins, one vaftly larger than the other 5 the body is rounded and very long, and is not covered with fcales, but a thick (kin ; the back is afh-coloured, and the belly white. Rondelct. de Aquat. p. 549. TbeZjgwia is a fpecies of fqualus, according to the Arte- dian fyftem of ichthyology. See the article Squalus. It is caught in the Mediterranean, and fometimes in different parts of the ocean. Some authors have called it Zygena, and others Libella ; which laft anfwers to the Englifh name of the Ballance-fi/b. ZYGASTICUM, Zwy*n*o*, among the antients, money paid for weighing things.

The word comes from Zvy§s a ballance. Pitifc. Lex. Antiq in voc. ZYG1T-/E) in the Roman galleys, a term ufed to exprefs thofe rowers in the triremes, or three-rowed galleys, who fat on the fecond row, that is above the thalamus and below the

Z Y M

thranifce. Meibcnu de Trirem, See the article Thala-

M I T JE.

Z YGOPHYLLUM, in botan y> the na me of a genus of plants delcribed by Linnaeus, the fanwwith the fabago of Tournefort.

See the article Fasago.

ZYGOSTATES, among the antients, an officer who was the overfeer of weights* and was to take care that tradefmen ufed none but what were juft. Pitijc. Lex. Antiq. in voc.

ZYMAR, a name given by fome of the chemical writers to verdigreafe.

ZYME, a word ufed by many authors to exprefs ferment or leaven. See the next article.

ZYMOLOGY, in chemiitry, a term ufed by fome writers to exprefs a treatife on fermentation, or the doctrine of fer- mentation in general.

This is a very extenlive thing, and were it well accounted for, might help us to fulutions of many things which at pre- fent appear extremely difficult to us.

Dr. Symplon has written a treatife on this fubject, wherein he refers the whole to the internal conflicts of acid and ful- phur in bodies, and feems to think that the phenomena of hot baths, the generation of minerals, and the production of mineral waters, the grand appearances of light, heat, and fire, and the generality of the fubterranean phenomena of damps, earthquakes, and firy eruptions, and the appearance of me- teors, may be all explained by the doctrine of fermentation, eftabiifhed on this bafis.

Fermentation, according to this author, is nothing but an inteftine collifion between acid and fulphur, put together by nature or art, and fet in a combating motion, in order to the production of concretes, or fome other end. The phenomena of hot baths are explained on this founda- tion, by obferving, that there is nothing of this kind without fulphur, evident even to the fenfes ; and that an acid of fome kind is neceflary in all mineral fermentation. Acids are well kn(*t.'n to be common in the earth, and on the conflicts of the t with :he fulphurs evident in thofe particular places, baths are made hot, and the minerals found about them are formed. Mineral fulphurs are of different kinds, and according to thefe it is found that the waters of thefe hot baths differ atfo, fome of them being fafe to take internally, and others only fit for external ufe; in this the acid alfo may have its {hare, for in its pajlage through the earth it frequently corrodes metalline ores', and carries their particles with it ; thefe, if of iron, give virtues to the water, and render it proper in feveral difeafes ; but if, on the other hand, they have diffolved copper, they becotne uiiwholfome.

The fulphurs and acids contained in the bowels of the earth, and occupying together large fpaces of it, are thus formed in- to a fort of" beds offctmenting and hot matter, through which the* water of thefe Whs paffing flowly and leifurely on, can- not but be heated to the degree we fee it of; and the greater the proportion of the* acid, and the more the place abounds with metalline or mineral ores, the more hot and the more impregnated with virtues of minerals the water will be. Ex- periments (Hew, that fulphur may be made to ferment vio- lently with acids, and that in this fermentation it becomes communicated, volatilized, and made capable of folution in wafer, though before it was not ; and hence is capable of im- pregnating the baths, as we fee.

Thefe mineral productions are not all that are referred by this, - and other authors who follow his fyftem, to the doctrine of acid and fulphur fermentations. The vegetable world is faid to be as much influenced by it, and the growth of plants, or vegetation itfelf, is laid to be only a natural and flow-paced fermentation from the peculiar acid and fulphur of each piarft. Tachenius's doctrine of acids and alkalies, is wholly difallowed in this fcheme, and even in a great meafure overthrown by it; and the doctrine of fubterraneous fires is not neceffary to heat the hot baths. It has been fuppofed that the fulphur, in or- der to give this heat to them, muft be itfelf flaming and burn- ing ; but it is proved in this fyftem, both by reafon and ex- periment, that fulphur properly combined with an acid, may both heat, and communicate its heat to other bodies by fer- mentation, without being itfelf ignited or burning within the bowels of the earth ; the great improbability of which, in many places where hot baths are found, has been one of the grand reafons for believing fulphur had no fhare in their pro- duction.

The acid, which is the other great caufe of fermentation un- der ground, may be either fuch as is inbred in the fame mi- neral concretion while in fucco foluto, or m the ftate of its original formation ; or an extrinfic and accidentally fuperve- ning one, which is well known to be of fufficient power for fuch an effect in the reduction of minerals already formed or completed. Some of the acid juices, which the earth in al- moft all parts abounds with, are loofe in themfelves, or fluctu- ating about, and others embodied in various animals : where they are bedded, and naturally contained in fulphur, they are always ready for thefe changes of fermentation ; but when they are in either of the other ftates, they can only act as brought upon the fulphurs by their own natural fluctuating courfe, or educed by water from the other minerals, and car- ried by it to the beds of fulphur.

} Thus