large mafs cannot be equal throughout its compofition, nor every where -liquid in the fame degree, it will be eafy to discover the caufe of feveral irregularities. If the depth of the bed is very confiderable, in proportion to its breadth, prifmatic pillars, without cross-divifions, are produced, at leaft lengthways from the uppermoft furface downwards. The third way is perfectly fimilar to the preceding in refpect to the effect, but is different from it by the mass being foaked with water, and by the burling of it afunder, which is the effect of the contraction whilft it is drying. If we fuppofe fuch a bed to be spread over a level space, the drying advances in the fame manner as the refrigeration in the former cafe. This feparation into ftrata properly happens when a confiderable quantity of clay enters into the whole compofition, because the clay decreases more than any other kind of earth in drying. We must now examine which of these two ways may best ferve to explain the manner in which the bafalts are produced, for it is hardly poffible that they fhould have been formed by cryftallization. However well founded the opinion may appear of deducing them from a melted fubftance, several very confiderable objections may nevertheless be raised against it, that I fhall not forget to mention. It seems therefore more credible to me, that they have been produced out of their fubftance whilst it was yet foft, or at least not too hard to be foftened by exhalations. If we therefore fuppofe that a bed is fpread over a place where a volcano begins to work, it is evident that a great quantity of the water, always prefent on these occafions, is driven upwards in exhalations or vapours; thefe it is well known poffels a penetrating foftening power, by means of which they alfo produce their first effect; but when they are increafed to a fuficient quantity, they force this tough moift fubftance upwards, which then gradually falls, and during this time bursts in the manner defcribed above. My reafons for this opinion are thefe; firit, we do not find the internal grain of the bafalts melted or vitrified, which however foon happens by fufion, and for that purpofe a very fmall degree of fire only is requifite. It confequently is very hard to explain how this fubftance could have been fo fluid, that no traces of bubbles appear in it (at least I have not been able to difcover any on the niceft examination into the Scotch and Icelandic bafalts) and yet when broken appear dull and uneven. I know very well that lava is feldom vitrified within; but the great number of bubbles and pores which are found in the whole mafs, are more than fufficient proofs that it has not been perfectly melted to its smallest parts, but has only been brought to be near fluid. Secondly, the bafalts fo much resemble the more fine trapp, both in refpect to their grain and original compofition, that they can hardly be diftinguished in fmall fragments, as will be more plainly proved in the comparison I hereafter make. See No. 24. But the trapp in all probability has never been melted, at least not in those parts where I have had had opportunities of examining it. Almoft in all the Weft Gothia ftratified mountains, the uppermost ftratum is trapp; and it must be properly obferved that it always lies upon black allum flate. Is it therefore credible that this fubftance, which in many places exceeds a hundred yards in depth, can have been perfectly melted without caufing the flate lying beneath it to lofe fome part of its blacknefs, even in thofe places where they touch one another, as this effect may be produced in a fmall culinary fire? There is befides a more fine kind of trapp, which is generally found in veins or loads, and frequently in very antient mountains, where not the leaft traces of fubterranean fire are to be seen. The bafalt mountains feem to be very antient, at least I do not know that the age of any one is afcertained. Should they then be fo old, that the fubftance of the trapp was not yet perfectly hardened, when were they produced? Befides, we frequently find to this day clayey fubftances at a great depth, which are fo foft that they may be fcraped by the nail, but afterwards become very hard when expofed to the air. There have without doubt been many eruptions of fire on the ifle of Staffa, as the fituation of the pillars, and their being removed Out of their places, evidently prove. You, Sir, have likewise brought a very clear proof of this from thence, which is a piece of balalt, that exteriorly is full of hollows, and in a manner burnt. A hard fubftance, when expofed to a degree of heat infufficient to melt the whole piece, may however be attacked by it in fome parts of the furface most liable to become fluid. The mixture of a large mafs is feldom every where fo uniform, that fome parts fhould not be more liable to melt than others. Crooked pillars may be produced as well by the drying as the refrigeration of a liquid mafs; for this purpose it is only neceffary that the furface fhould be bent, as the ftratum always runs in a parallel direction with it. From what I have hitherto faid, you will perceive it is my opinion, that the bafalts have been produced by the affiftance of a fubterranean fire, but that it is not yet determined whether they have been feparated by the fufion, or by drying: this laft however appears more credible to me on account of the reafons I have mentioned. For to speak ftrictly, the fubftances inclofed in the bafalts, though they fhould even be volcanic, do not yet with certainty prove a preceding fufion, as a fubitance foftened by water may be as proper for it as one fufed by fire. I am, however, very far from being inclined to maintain my opinion any farther than it agrees with certain experiments and obfervations. Truth will fooner or later be difcovered; and I know nothing more derogatory to the honour of a natoral hiftorian, than having wilfully obftructed its knowledge. Homo naturæ minifter & inter pres, tantum facit & intelligit, quantum de naturæ ordine, re vel mente obfervaverit, nec amplius feit aut poteft. Baco, H 2 Naturel Natural Hiftory of the Grana Kermes, or Scarlet Grain. From Dillon's Travels through Spain. valuable productions with which the beneficent hand of nature has enriched the dominions of Spain, the Grana Kermes is chiefly deferving of attention. This valuable production had been confiderably neglected in that kingdom fince the importation of cochineal from America; however, the royal Junta de Comercio, or board of trade at Madrid, having an eye to the further advantages to be drawn from this precious article, gave orders a few years ago to Don Juan Pablo Canals, director general of the madder and dyes of Spain, to report the fate of this product; and to him I am indebted for the prefent information on this fubject. The grana kermes is the coccos baphica of the Greeks; the vermiculus, or coccum infectorium of the Romans; and the kermes, alkermes, of the Arabs; being the ingredient with which the antients ufed to dye their garments of that beautiful grain colour, called coccinus, coccineus, or cocceus, different from the purpura of the Phoenicians, which at firft had been obtained from that tetaceous fish, called the murex *. But in courfe of time the purple colour and other tints having been more eafily effected by means of the kermes, the murex was on account of the expence, and the kermes we are now speaking of, was introduced; which giving a ftronger and brighter colour, was univerfally adopted, and fupported its reputation for ages, till the dif covery of America; as is evident from the many old tapestries, damafks, and velvet hangings, ftill preferved in cathedrals, which feem yet to retain their primitive luftre and brightness †. In the reign of Lewis the fourteenth, Giles and John Gobelin, in the year 1657, under the pa tronage of Colbert, introduced the fecret into France of dying woollen of that beautiful fcarlet called after their name, which was done with the kermes that had been long in ufe in Flanders, where many old pieces of tapeftry, though above two hundred years old, had fcarcely loft any thing of their bloom. But cochineal, Being now introduced into the dyehoufe, fo called from the Latin word coecinella, as a diminutive of coccum, and giving that brightnefs to fearlet, at firit called Dutch, and afterwards Paris fcarlet, the invention of which, according to Kun Though the dye obtained from the murex was thought to have been loft, it feems to be known on the coafts of England, France, Spain, and the West Indies, though neglected on account of the great trouble and expence. See Padre Feijoo, Theat. critico, tom. 6. difc. 4. According to Gage, they find a fhell-fish in the feas of the Spanish West Indies, which perfectly refembles the ancient purpura, and in all probability is the fame. Cloth of Segovia dyed with it, ufed to fell for 20 crowns the ell, and none but the greatest Spanish lords wore it. Don Antonio de Ulloa alfo gives a particular account of this fish, and the ufe made of it in America. This was the colour called carmefi, by the Spaniards; cramoifi, by the French; and crimion, by the English. kel, kel, is owing to Kufter, a Ger- Perfia, where it was first made man, by means of a solution of use of. tin in aqua regia; the kermes then began to decline, and yield in its turn as the murex had done before, of which Colbert makes a particular complaint, in his general inftructions to the dyers of France, in the year 1671. Infenfibly, the kermes was totally laid afide, and cochineal made ufe of, not only in yarns, but also in filk: this new method being every where in fashion, except at Venice, and in Perfia, for fcarlet, and in other parts of the east for crimfon. The ancients thought the kermes was a gall-nut on account of its figure and fize, not being larger than a juniper berry, round, fmooth, gloffy, and rather black, with a cinereous down. It is found fticking to the branches, or tender leaves of the oak called in Spain cofcoxa, a derivative of the Latin word cufculium, the coccus illicis of Linneus, likewife called carrafea in Spanish, from the Arabic word yxquerlat, foftened afterwards to escarlata; being the fmalleft fpecies of oak, the fame which Cafpar Bauhine and other botauifts call ilex aculeata cocci-glandifera. This tree, whofe height is about two or three feet, grows in Spain, Provence, Languedoc, and along the Mediterranean coaft; alfo in Galatia, Armenia, Syria, and Jofeph Moya, a Catalan writer of the last century, published a treatise entitled Ramillet de Tinturas, dedicated to the city of Barcelona, under the feigned name of Phefio Mayo. He fays, the kermes is common all over Spain, principally in that part of Aragon bordering on Catalonia, in Va. lencia, and in the bishoprick of Badajoz in Etremadura, as likewife in Setimbre of Portugal, where it is the beft, and equal to the kermes of Galatia and Armenia. Mr. Hellot of the French academy of fciences, in his art of Dying, chap. 12. fays it is found in the woods of Vauvert, Vendeman, and Narbonne; but more abundantly in Spain, towards Alicant, and Valencia." It not only abounds in Valencia, but also in Murcia, Jaen, Cordova, Seville, Etremadura, la Mancha, Serranias de Cuenca, and other places. In Xixona and Tierra de Rel. leu, there is a district, called De la Grana, where the people of Valencia first began to gather it, whole example was followed all over Spain. It has, fome years, produced thirty thousand dollars (50001.) to the inhabitants of Xixona. In the year 1758, there went out of that town, Relleu, Buffot, Caftilla, Ibi, Tibi, Unil. Santa faz, Muchiamel, and San Juan de la Huerta de Alicante, "As the Phoenicians neglected the ancient purple, and gave a preference to the scarlet, whofe colour is lefs coftly and more beautiful; just so, the French have forfaken our fcarlet for that of the Dutch. This new invented colour was at firft in efteem on account of its brightnefs; but being lefs durable than that of France, and under a notion that they were both equally liable to fpots, they were foon laid afide, which occafioned the downfal of our most valuable cloth manufactures." above a thousand perfons to gather the kermes, which was afterwards fent to Alicant, where it was put into cafks for exportation, being chiefly fhipped for Genoa and Leghorn, paffing from thence to Tunis. In the fame year, 1758, they gathered about 300 arrobes of kermes at Xixona, which fold for about twenty-four dollars (4 1.) the arrobe *, with about fix per cent. duty and fhipping charges, till on board. In the kingdom of Seville it is put up to public fale, and is generally bought by the people of the neighbourhood, who fell it, again for exportation to the merchants of Cadiz. Both antients and moderns feem to have had very confuled notions concerning the origin and nature of the kermes; fome confidering it as a fruit, without a juft knowledge of the tree which produced it; others, taking it for an excrefcence formed by the puncture of a particular fly, the fame as the common gall obferved upon oaks. Tournefort was of this number. Count Marfigli, and Dr. Nifole, a phyfician of Montpelier, made experiments and obfervations, with a view of further difcoveries, but did not perfectly fucceed. Two other phyficians at Aix, in Provence, Dr. Emeric, and Dr. Garidel, applied themselves about the fame time, and with greater fuccefs; having finally difcovered that the kermes is in reality nothing elfe but the body of an infect transformed into a grain, berry or hufk, according to the course of nature; whofe history I fhall now briefly relate : The progrefs of this transformation must be confidered at three different seasons. In the first ftage, at the beginning of March, an animalcule, no larger than a grain of millet, fcarce able to crawl, is perceived flicking to the branches of the tree, where it fixes itself, and foon becomes immoveable; at this period it grows the molt, appears to fwell and thrive with the fuftenance it draws in by degrees: this state of reft feems to have deceived the curious obferver, it then refembling an excrefcence of the bark: during this period of its growth, it appears to be covered with a down, extending over its whole frame, like a net, and adhering to the bark: its figure is convex, not unlike a fmall floe: in fuch parts as are not quite hidden by this foft garment, many bright fpecks are perceived of a gold colour, as well as ftripes running across the body from one fpace to another. At the fecond flage in April, its growth is compleated, its shape is then round, and about the size of a pea it has then acquired more ftrength, and its down is changed into duft, and feems to be nothing but a husk, or a capfule, full of a reddish juice not unlike discoloured blood. Its third ftate is towards the end of May, a little fooner or later, according to the warmth of the climate. The hufk appears replete with fmall eggs, lefs than the feed of a poppy. These are properly ranged under the belly of the infect, progreffively placed in the neft of down, that covers its body, An arrobe is 25lb. Spanish weight; 100lb, Spanish weight equal to 971b. English. |