Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/524

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Which, four millions of a young fpider' $ threads are not fo big as the fingle hair of a man's beard. The eggs of fome fpiders are a very pleafing rnicrofcopic object ; they are round at one end, and flattilh at the other, With a deprcfiion in the center of the fiattifh end, and a yellowifh circJe round it. The colour of thefe eggs is a pearly or bluifli white, and when the young fpiders hatch, they come out in their perfe£ form, and run about very nimbly. Tke female fpider depofits her eggs* to the num- ber of five or fix hundred, in a bag compofed of her own Web, which fhe either carries under her belly, or hides in fome very fafe recefs. Philof. Tranf. N 3 272. The young fpiders are always very beautiful objects for the microfcope. The current of the blood may be eafily dis- covered in their legs, and part of their bodies; and many other curious particulars occur in their direction. There are two or three fpecies of this animal, peculiarly worthy the attention of the curious in rnicrofcopic difco- veries. . 1. A little white feW-fpidcr with fliort legs. This is found plentifully among new hay, and its body appears like white amber with black knobs, out of which grow fliort- but fliarp prickles. The eyes of thefe may be very diftinctly feen, being very brifk and lively, and fome have fix, fome eight of them : each eye has a pupil of a violet blue, which is beautifully clear and tranfparent, and is fur- rounded by a circle of pale yellow. 2. The wandering, or hunting fpider, that (pins no webs, but runs and leaps by fits. This has two tufts of feathers fixed to its fore-paws, which make a very beautiful appearance before the micro- fcope. The variety and beauty of colouring alfo, all over this little creature, afford a very pleafing fight. 3. The long-legs, or fhepherd-yp/'<&r. This is a molt wonderful crea- ture : it has two fore-claws at a great diftance from the head, tipped with black like thofe of a crab, and opening and (hutting like the fcorpions ; thefe are ferrated or indented on 'their mfide. When all the legs are cut from this fpider, and it is examined by the microfcope, it will be feen that the protuberance on the top of its back is furnifhed with two fine black eyes. Power's Microf. Obf. p. 13. Hook's Mi- crogr. p. 200.

The venom of many kind of fpiders is greater than ufually fuppofed : we have, in the Philofophical Transitions, an account of a perfon in New-England who was bitten by a fmall fpider a little above his ankle; he perceived the crea- ture biting, and crufhed it to death upon the wound, be- tween his flocking and his leg ; in half an hour he felt a pain in that leg, which in another half hour extended itfelf to the groin, and at the fame time he had a creeping pain in the calf of his other leg ; and in a quarter of an hour after this it affected his ftomach, his back, and his head. The pains were not conftant and fixed, but erratic, and very acute, and his pulfe was extremely low and heavy. He was relieved, by taking internally fpirit and fait of hartfhorn in viper-wine, and applying a cataplafm of garlick to the part, and in three or four days wholly recovered. Boccone mentions a fpecies of large fpider, common in the ifland of Sardinia, whofe bite proves mortal within the fpace of a few hours ; the whole body ufually fwells almoft im- mediately, in confequence of this bite. The cure is per- formed by oil of olives, in which the creature is infufed over the heat of a ftove. This is a medicine they always keep ready in the houfe, and while they ufe this externally, they give large dofes of Venice-treacle inwardly, diffolved in ftrong wine : but many die of this bite, either from the want of power in the remedies, or from their being ufed too late. Boccon. Muf. de Fif.

When fpiders afcend and defcend by their thread, they do not fpin a new one at every defcent; but whenever they afcend, they wind the thread with their feet into a fort of coil, and when they defcend, they only unravel it again. Phil. Tranf. N° 482. feet. 16.

Some think the white matter, we often find floating in the a irtowards the end of the fummer, is produced by fpiders. Ibid. See the articles ^V-Threads, Opilio, Phalan-

GIUM, C3°C.

SpiDER-wwrf, in botany. See Phalangium.

SPIEI, in the glafs trade, an iron inflrument, hooked at the end and pointed, with which the workmen take the metal up out of the melting-pots for proofs or efiays, to fee whe- ther it be fit to work. Neri'sArt of Glafs, p, 241.

SPIGNEL, in the materia medica, &c: the Englifh name of the plant called by botanifts meum. See Meum.

SPIGOLA, in ichthyology, a name given by Paulus Jovius, and fome others, to that fpecies of pearch which is gene- rally called the lupus marinus. See the article Lupus. It is a genuine pearch, and is diftinguifhed from the others by Artedi, by the name of the pearch with the thirteen rays in the fecond back fin, and fourteen in the pinna ani. Authors have called two different fifti by this name lupus marinus, which conveying no diftinct idea of the characters of the fifli, was applicable to either as much as the other; but this name of Artedi admits of no equivocation, and muft always difHngtiifh the fifh.

SPIKE, or Oil of Spike, a name given by our druggifts to an

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effehtial oil, much ufed by the varnim-makers and the paint- ers in enamel ; and of fome \x(z in medicine. This oil, when genuine, is brought from Provence, and fome other parts of France, and is there made of lavender. This plant is called in Provence afpic, and thence came the name oil of afpic, which afterwards degenerated into oil of fpike.

The manner of making the oil upon the fpot is this : when the flowers are. perfectly ripe, they put them into an alem- bic with a great quantity of water, and this they diftil after feveral days maceration : there arifes with the water a large quantity of an oil of a fine pale amber colour, and this feparated from the water, is the true and genuine oil of fpike.

The flower of this plant is the part which yields the largeft quantity of oil ; as is the cafe with all the plants with galeated flowers, of which the hufk or flower-cup ufually contains almoft all the oil of the plant. The aromatic plants, in general, yield indeed but a fmall quantity of oil, but the vaft abundance of this plant, in thefe places, makes the ex- pence of gathering it fo fmall, that the oil is very cheap. The quantity required on feveral occafions is, however, much greater than what all the lavender of the country can yield ; and the price it is expected to be fold at is fo fmall, that it is not to be wondered that there are feveral common adulterations of it.

The moft ufual ways of fophifticating it, however, are two ; the one with the fpirit of wine, which is efteemed the Ieaft hurtful, and the oil thus fophiflicated is often called the very beft of the country. The method Mr. Geoffroy took to difcover the cheat was this : he procured along and narrow vial, of an equal diameter all the way up, into this he firft put an ounce of fair water, and to this he added an ounce of the oil; he marked the height of the water in the vial, then fhook the two liquors together, and they became milky, and heated on the mixture, which alone would have been a fuificient proof that there was fpirit of wine in the oil. After fome ftanding the liquor became clear, and the oil floated at the top, but in a much fmaller quantity than might have been expected, there being not more than a quarter of an ounce of it, the reft having been fpirit of wine, which mixed with the water, and thus left all the true oil, which was only one fourth of the quantity, to float alone on the water, which was greatly encreafed in height in the vial. A pint of this oil of fpike, therefore, contains only four ounces of the genuine oil, and twelve ounces of plain fpirit of wine.

The fecond method of adulterating this oil, which the fame gentleman had fufpected, was eafily difcovered next : for on mixing this quarter of an ounce of pure oil of fpike with three quarters of an ounce of oil of turpentine, there was produced an ounce of a liquor, which appeared wholly the fame with the oil of fpike commonly fold in the druggifts fhops. And indeed, much of what is ufually fold is worfe than this, being no other than oil of turpentine fcented with a fmall quantity of the true oil of fpike. The ready way of difcovering the oil, counterfeited with oil of turpentine, is to wet a paper in it, and fet it on fire; the turpentine will here be difcovered by the thick fmoak it yields, it being, of all vegetable oils, that which yields greatly the thickeft cloud in burning : and, on the contrary, that which has been adulterated with fpirit of wine, will be diftinguifhed by the fame trial, by its yielding a much finer and thinner fmoak, and burning with a bright blue flame. If they be tried by firing them in a fpoon-, that which is adulterated with fpirit of wine will burn very bright, and yield no fume at firft ; but as it grows near the bottom, it will fmoak a little, and finally will leave no refiduum, ex- cept that it varniflies over the infide of the fpoon : that adulterated with the oil of turpentine will burn more vehe- mently, fmoak more, and leave a coarfer varnifh upon the fpoon ; and if it be of the coarfeft kind, that is, if it have been adulterated with badly-rectified oil of turpentine, the fume will be the more abundant, and there will be left in the fpoon a fetid matter, refembling melted pitch. Mr. Geoffroy tried whether, in the bufinefs of varnifhing, the oil of turpentine alone might not do as well as the oil of fp'tke ; he found that it dried perfectly well, but that it left a ftinking fmell upon the work, which never went off; whereas the mixture of this oil, with that of fpike, makes a fmell like neither, and which foon goes off. An ounce of oil of turpentine, with only twenty drops, ei- ther of our common oil of lavender, or the pure oil of fpike, makes a liquor tolerably well fcented, and which ferves for the purpofes of oil of fpike. If two drachms of our oil of lavender be added to fix drachms of fpirit of wine, they immediately mix, and this afterwards mixed in a fmall pro- portion with oil of turpentine, makes a fort of oil of fpike. The moft regular method, however, that the artificer can ufe, if he can get the genuine oil of fpike, is to mix one ounce of it with three of oil of turpentine, which perfectly fits it for his purpofe, and makes it the fame with' that in. common ufe. The method of making this perfectly pure, is to rediftil it in a balneum maris ; there will thus be pro- cured