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as soon as the caterpillar ceases to eat, and prepares to change into a chrysalis
Mirror points. The butterflies, adorned with these spots, are called in French, peacock-butterflies. M. de Reaumur nan.es their spots, eye-spots.' The Dutch call these butterflies, in their language, peacock's eyes, and peacock's tail; because their spots resemble much those spjts like eyes, that adorn the tails of these birds. In other respects, the criticism of Lesser is not very interesting to Naturalists i it i;> of little consequence wrut names are given to things, provided people are agreed concerning the things designed by these names: and it is even better, to preserve i proper nimcs already received, than to give more suitable cp.'S, which are new; because, science is interested, that each thing have a single name, that the memory of those who learn, may not be uselessly burdened: which is but too much the cafe already in botany.
Page 186,1. 24.
As if they were the ivork of a painter. Of all known anim ils, there are not any, which, for the beauty and agreeable disposition of their colours, can be compared to butterflies. There are some, wh ch cannot be seen, without admiration. And, as if it was not enough, that Nature had lavished 011 them, whatever is most beautiful and perfect of this kind, there arc, besides, some of them, where g"ld, silver, and mother of pearl, appear w;th wonderful splendor. Akho' Europe produces many butterflies of extraordinary beauty, they are, in general, however, much inferior to those which come to us from the Indies: besides the advantage which these last have, of being, for the most part, larger than ours, it would seem, that the brilliance of their colours increases in proportion to the heat of the climate, of which they arc natives.
Page 187,1. 3.
Or rather, those fathers. It has been said above, that thy are not feathers, but scales, or small laminæ.
Pace 191,1. 7.
'Regaled with the diJJj the Magijlrates of Franifort. Locu*s must formerly have been a food, known in Judea, and
the the neighbouring countries; since Moses permitted the Jews to eat four sorts of them, as the author his observed above, and the Scrirrure informs us, that John the Baptist lived on locusts and wild honey.
Besides, it is not in the Indies alone, that insects are considered by the inhabitants, a? a delicate food. Every body knows, with what pleasure Europeans eat the sea-eggs, crabs, lobsters, oysters, mulcles, and other sheil-sisti. Snails that seed on vines, and even some ll gs, are not rejected. I do not mention the th'ghs of frogs, vipers or turtle, because, for the reasons I have given above, I do not consider them as insects.
Page 193,1. 4.
*7he Jifle-vuorth draws fr<tn its body, threads. Boyle; in his Essay on the Subt'dity of tjftuviums, (Jh. II. mentions a lady, vrho, having taken tne trouble to undo the coque of a silkworm, found, according to her calculation, that the thread was about 300 English n.iles in length;—The Author.
There has certainly been some etror here. I have of'cn measured tl.e thre.id which forms the coque of the silk worm, and I have never in general, found it longer than from 700 to 90a seet. Supposing, with the author of the Speclacle de la Nature, who cites Boyle, that the thread of a Coque is 930 seet long, and weighs two grains and a half; I find, that it would require a thread, 3,428,352 fvtt long, to make a pound of sik, from which it would follow, supposing these seet standard, that a pound of silk would extend to 228 French leagues, supposing each league i5,000 seet long, or 3000 geometrical paces;
Page T94, I. 19.
So far as to mate a suit. I do not believe; that M. Bon carried the matter quite so far: but we are informed, in the Memoirs of the Royal Academy of Sciences, i710, that he presented to the Academy, the year before, stockings and gloves, mad; of the webs of spiders.
This led the Assembly, to recommend to M. de Reaumur, and another member, to follow out the discoveries of M. Bon. Reaumur did so, and the following is, in general, the result of his experiments. He found, that the webs of spiders, were by no means proper for use, because the thread of them is too delicate, requiring ninety to make a thread, equal in strength to that spun by the silk-worm,
3 U 2 and and about 18,000 os them, to compose a thread sit for sew*mg, as strong as the threads used for that purpose, made os silk. There remained, therefore, nothing but the coques which they weave round their eggs, from which any utility could be expected: he examined these, and found, that none but those of such spiders as weave webs, with ray's proceeding from a centre, round which runs a spiral threads could be of any use, the coques of the other kinds furnishing but little thread, or that thread not possessing the necessary qualities. It was then to be discovered, if silk could be made from those coques, as cheap as common silk; or if dearer, it would also be more beautiful.- The first question'was soon decided. Although M. Reaumur found in earth-worms, and in the soft substance of young feathers,a food agreeable to spiders, and easily procured, and that thus, the difficulty of providing them with a sufficiency cf Hies was obviated, he met with another, which he could not remove, and that was, the mutual hatred they bear to one another, which precluded every attempt to breed them together. It would therefore have been necessary to rear them separately, which could not have been done without infinite trouble, and consequently without great expence, and considering, that he found the threads of the coques of spiders to be five times more slender than those of the silkworm, and that it required twelve times n ore spiders than silk-worois to furnilh the fame quantity of silk, insomuch, that to procure a single pound of spider-silk, he needed almost ei^ht and twenty thousand coques, which could not be had without breeding a much greater number of spider?, as the females only make them, he was convinced, that spidersilk would cost infinitely more than common silk. It only remained, then, so know whether it would be more beautiful-, and this, M. de Reaumur was persuaded would not be the ease; on the contrary, he found that it had less lustre, and the r«ason he gives for this, is, that the threads which compose the silk of spiders, are more delicate, and more crisped, than those of the silk-worm.
From all this, we lean., that it is not by rearing spiders,
that we can expect to turn this silk to advantage
The only' means, perhap.s, by which we might profit by their labours, would be, by observing the time when they flyln the a>r, suspended by their threads, or when they are preparing for such expeditions, and then to fend country people into the fields, to collect those threads with rakes.
There are certainly times, when in a sew hours, a large quantity might be gathered. I have often seen the meadows qyiite covered with it. Perhaps, by carding and spinning this thread in the manner of flax, it might be turned to some use; at any rate, it would cost very little to try the experiment.
Page 195,1. 26.
A manufacture established. However industrious the Dutcli may be, in what relates to trade and commerce, they have never yet attempted the breeding of silk-worms in Holland} those who rear them there, doing it only for thfir own amusement. There is but a single individual in these Provinces, who has carried it to any considerable degree. It succeeded so well with him, that it is said, the silk-worm alone has enabled him to build and maintain a very sine Country feat, in the neighbourhood of Utrecht. The machine he erected there, and which is moved by the fall of a very small rill of water, deserves to be seen. It turns six thousand bobbins, and winds as many coques at the fame time.
Page i96,1. i4.
If one should calculate. This calculation, if I am not mistaken, would, in a dozen of years, amount to sive hundred and thirty one thousand, four hundred, and forty one hives, supposing that no hives had perished during the time, and that each had regularly produced two swarms a year.
Page 196,1. 35.
The cochineal is a small worm. The cochineal is not a small worm, which produces a scarabseus; it is one of thole animals, which M. de Reaumur calk Pro-Gall-insects, that is to fay, insecti which difser from those he calls Gall-insects, Only in that thefe last have the body very smooth, when they are large; while the others preserve those wrinkles or articulations, which g»ve them more the appearance of insects, and make them less like galls, than what he calls gallinsects.
The gall-insect, in other respects, and the pro-gall-insects are both animals with six seet, and there are many species of them. The largest known, hardly attains the size of a middling pea. While they are very small, they are active, and run about with great vivacity, but the semales, when they become larger, six themselves to some part of a plans; or tree, the substance of which they suck; there they afterwards attain a1 considerable bulk, and with it, lose the power of changing place, and even all the external sigure of an animal, assuming that, nearly os a gall, into which one would think they were metamorphosed. It is in this motionless and immoveabl? state, that they receive the intercourse of ths male, which is now transformed into a very small fly, is an active animal, and is, in no respect, like the semales. These, after the embraces of the male; without changing place, lay their eggs in great numbers, which 'hey pass from the extremity of their abdomen, and loJge under their belly: they now ilie, and their body, which still remains sixed to the fame spot, serves as a cover to the eggs, to preserve them from the injuries of the air, till the young One? are hatched, and issue from this cadaverous protection, to transport themselves elleu here.
Page i97,1. 2.
Suri the fine red fruit. The juice of the fruit of the Cactus opuntia, is, it is true, very red, and is so indeed, to such a degree, that it changes the colour of the urine of persons who have eaten of it, into a deep fed, like bio d: but, it is not the fruit which the cochineal sucks; it is the leaves of the plant which are green, and have no red juice 5n them. It is probable, that, as the sap of this plant undergoes in the fruit,- that alteration which gives it the red colour, it likewise undergoes a similar alteration in the body of the cochineal.
M. de Reaumur, in the second Memoir of his 4th volume already cited, enters into a very curious diieussion on the cochineal and the manner of gathering it. What he there fays, deserves the more consideration, that it is founded on authentic documents, judicially proved,and elucidated by his own observations. He concludes, by shewing the importance of these insects as an article of revenue, and sor this purpose, he quotes a Dissertation of M. Neufville the Dutch envoy, who proves, that 700,000 pounds weight of sine cochineal, are every year imported into Europe, and at least i8o,coo pounds weight of an inserior fort. The sirst sells for ten florins, ten ibus; and the other, for thirty Dutch sous a pound, the whole amounting together to 7,410,000 florins, Dutch money, or upwards ©f L. 650,000 sterling, which is consequently