Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/519

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The fpecific flames, taken from the excefs of the parts, or from tome particular parts which that fpecies has, and which the others want, are preferable to all others. The principal parts, which ibmetimes are in excefs, ibmetimes are defi- cient, and therefore give the proper origin to thefe names, are thefe. The tarn", or long-fhaped flefhy filaments hang- ing from the mouth; the tubercles, which in the heads of fome tithes imitate horns; the prickles which are on the heads, and other parts ; and the prominences, and other foft apophyfes ; and other fuch remarkable things, in whatever part of the body. Inftances of proper fpecific names, found- ed on the excefs or defect of thefe parts, are thefe. Gadus ore cirratOj and gadus c.rris carens. Coitus cornubus quatuor in capite. Coitus cornubus capitis carens, &c. After thefe, the beft: names are thofe which are taken from the number of certain parts differing in excefs, or fmall num- bers, in the feveral fpecies. The fins, and their bones, and the prickles of them, are parts which give thefe names, as alfo the fpines on the heads and bodies of fome fifties, and the linens later ales, or fide lines, and the teeth. Of this kind are thofe expreffive fpecific names < f the gadus dorfo diptcrygio, gadus dorfo tripterygio, gajlcrojlms aculcis decern, &c.

Others of thefe names are taken from the proportion of fome two parts one to another. The difference of this kind is generally in regard to length; and the parts alluded to, are the jaws, the teeth, &c. Of this fort are the clupea man- dibida fuperiore longiore, and the like. In the fquali, and fome other cartilaginous fifties, the upper part of the tail is always longer than the under part ; but as this holds in all the genus, there can be no ufe made of it as a fpecific cha- racter.

Others of thefe names are made from the figure of fome par- ticular part, different from the reft of the genus. The parts alluded to in thefe names are generally thefe ; the fnout, the back and belly, the tail, the lateral line, and the fixed fpots and colours. The fnout of any fpecies, when different from that of the others of the fame genus, in being conic, deprefted, or comprefled, or long and cylindric, gives great opportunity of good names of this kind. Thus we have the names of coregonus rofiro conica, and coregonus roflro dcprejjo, and the like. The back and belly, when plane ridged, or carinated, give occafton to fpecific names in the fame man- ner; the cyprini in particular give us inftances of this. The tail gives alfo occafton to many names, as it is cufpidatcd, rounded, ftrait, lightly hollowed, or forked ; and the lateral lines give the fame occafions of names, as they are ftrait, crooked, fingle, double, csrV. The fpots, provided they are permanent, are good for the bafts of fpecific names, exprefl- ing whether they are round or long, large or fmall, ftrait, or tranfverfe. The fituation of the fins, and other parts, is generally fo regular in all the fpecies of the fame genus, when that genus is naturally eftablifhed, that very little can be done in the making names from them as fpecific ones ; but this fituation of the parts is of the utmoft ufe in the ge- nerical diftinctions.

All fpecific names, founded on thefe characters, are genuine and proper, and fupply real notes for the diftinguifhing the fpecies ; and whoever will examine together all the fpecies of any one genus, however badly named by the old authors, will find, in all the really diftinct fpecies, marks fufficient for the making fuch names as are here prefcribed. No fifh can want thefe, fince its being a diftinct fpecies from the reft confifts in fome of the articles, on the tlefcription and di- flinction of which that name is to be formed. Artedi's Ich- thyology. SPECTABILES, among the Romans, a title of honour given to the fecond rank or degree of nobility under the Roman emperors, being unknown in the time of the republic. There were other two degrees; the firft had the title of illufires, and the third that of clariffmu Pitifc. in voc. SPECTER, in conchy] iology, a name given by the French jiaturalifts to a fpecies of valuta, on which there are feveral reddifh broad bands, compofed of loofe and irregular figures ; the ground colour is a fine white. They are called by Latin writers concha fpeclrorum. See Concha.. SPECTRORUM candela, in natural hiftory, a name by which fome have called the belernnites. See the article Be-

LEMNITES.

SPECULA, among the Romans, were places whence a good view might be had of what was doing at a diftance. The word is particularly ufed to fignify watch-towers and beacons. Fitifc. in voc.

SPECULARES, in natural hiftory, the name of a genus of foffils of the clafs of the talcs.

The word is derived from the Latin, fpeculwn, a looking- glafs ; the bodies of this kind being naturally of bright glofly and polifhed furfaces, and in the thicker mafles npt tranfpa- rent, but reflecting the images of things. The fpeadares are talcs, compofed of vifibly feparate plates of extreme thinnefs, and each fiffile again into a number of others yet finer. See Tab. of Foffils, Clafs i. The bodies of this genus are the common Mufcovy talc ; the fptcularis lucida fufca, or brown talc, a fpecies little in- f Suppl. Vol. II. '

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ferior to the former in beauty, and found in Germany an<f England ; and the fpeadaris amethyjlma, called talc rouge % or red talc, by the French. This j s found in Mufcovy and i effia, and no where elfe, as far as is yet known, and is often imported into France in manes, which are of a beau- tiful purple : we have of it brought into England, but only m thin flakes, fit for the Covering miniature pictures. In theie flakes it has none of the rednefs natural to it in the lump, but is the fineft and moft tranfparent of all the talcs. Hilt's Hift. of Foffils, p. 71. 74.

Pliny, and other of the antient writers, as well as feveral of the moderns, ufe the term fpccularis lapis for that fpecies of talc, commonly known by the name of ifinglafs, or Mufcovy glafs.

This has been a fubftance in great ufe among mechanics, from the eariieft times we have any accounts of. It is found in broad fiat mafles of ten or twelve inches in breadth, and from half an inch to three inches in thicknefs ; and is com- pofed in thefe of an almoft: infinite number of broad and beautifully even plates, or flakes, laid with a perfect regu- larity on one another, and feldom parting naturally from each other, though by art they maybe divided, almoft with- out end, into broad and extremely thin lamina?. Thefe are very flexile and elaftic, and make no effervefcence v/ith aqua fortis. By the laft of thefc properties they are diftinguifhed from the plated fpars which fome have confounded with them, and by their elafticity from all other foffile bodies. It is found in many parts of the world. The iflaud of Cyprus abounds with it. It is very common alfo in Ruffia, and has of late been difcovered to abound in the Alps, the Apennines, and many of the mountains of Germany. It is imported in large quantities into England, and is ufed by the Ianthorn-makers inftcad of horn, in their nicer works ; by the painters to cover miniature pictures; and by the micro- fcope-makers to prcferve fmall objects for viewing by glaffes. The antients ufed it inftead of glafs in their windows. Hill's Hift. of Foffils, p. 72.

SPECULARIA, among the Romans, a kind of window-cafe- ments, which were ufed before glafs was introduced for this purpofe. They confifted of tranfparent ftones, called lapides fpeadares. Pitifc. in voc. See Specularis lapis, Cycl. and Suppl.

SPECULARIS lapis. See Speculares, fupra.

SPECULATION {Cyrt.)*~ Speculation-^//, in natural hiftory, a name given by the French writers to a very beau- tiful fpecies of the vrfuta, ufually called by us the Guinea- fbell, from its being brought from that part of the world. See the article Voluta.

SPECULATIVE (Cycl.)-— Speculative muftc, called by the Italians mufica fpeculativa, or tbeorica, that which treats only of the founds, examines their natures, properties, and effects, without regard to the executive part.

SPECULUM {Cycl) — Speculum lingua, a Ghirurgical in- ftmment. See Glossospatha.

Speculum indicum, an affected term ufed by fome chemical writers to exprefs filings, of iron.

SPEEDWELL, veronica, in botany. See the article Ve- ronica.

We have feveral of the exotic kinds of this plant propagated in the gardens of the curious. They may all be raifed from feeds, but their roots encreafe fo faff, that they are ufually propagated by patting them. The beft feafon for doing this is in September, and the fummcr following they will produce their flowers in full perfe£tion. They will grow in any fituation, but they thrive beft in a frefh foil, that is not too wet. They require no care but the being kept clear from weeds, and having their roots parted every autumn, otherwife they multiply too fffift, and both choak up them- felves, and injure whatever is near them. Miller's Gard. Diet.

SPEISSE, in mineralogy, a name given by the Germans, and other workers on cobalt, to a fort of impure regulus of bifmuth, Ibmetimes occurring in their procefles. It is not uncommon for ores of bifmuth to be mixed with the cobalt in the fmalt-works. Both this ore and the cobalt yield the blue verifiable earth of which fmalt is made, but in one of them it is blended with arfenic, and in the other with the bifmuth. The feparating it from thefe two mine- rals requires different procefles, and the workmen therefore feparate the two minerals, and work each by itfelf; but it fornetimes happens that the ore of bifmuth is fo like to the true cobalt, that it cannot be diftinguifhed by the eye, and fo intimately mixed with it, that it cannot be feparated from it ; in this cafe the whole is expofed to the fire together, and, after the arfenic is fubhmed in form of meal, there remains acoarfe and impure regulus of bifmuth, which having mixed itfelf with the earth of the cobalt, and other extraneous fubftances, is of a reddifh white colour, and very impure and friable. This gives them the trouble of a fecond ope- ration, by which they feparate the pure regulus of bifmuth, and the remainder being a mixture of its earth and that of the cobalt, is run together into the blue glafs, called fmalt, the earth of bifmuth ore being of the fame nature with that of cobalt. Philof. Tranf. N-396. p. 199.

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