« AnteriorContinuar »
tort of flower, and to those that are grateful perfume, and used as such most strongly scented; they form by the women for scenting their lilargenosegays of honey-suckles, of nen, and yet the effluvium of this lillies, of elder-flowers, &c. These sort of fruit is fatal. good people, however, act on a prin There should not then absolutely ciple drawn from their own method þesuffered to remain either fruits or ofliving, and only err because they flowers in thespinning place. But. cannot suppose that flowers can as we have seen by the experiment shed a malignant vapour, so foreign made on mulberries, by Dr. Ingento their sweet scent;
their houses are Housz, that this fruit produces a not, in general , either too clean or poisonous air, the greatest care agreeably perfumed. The exhala- ought tobe taken, more particularly tions from the dunghills of their when ripe, to pluck them off and sefarm-yards, the preparations oftheir parate them from the leaves; it is in kitchens, where garlick, onion, vain to object against it, by alleging cheese, and the smell of frying ale that the silk-worms love and eat ways reigns, form fætid vapours, them;for do wenoteat peaches with which scarcely ever quit their babi- out being incommoded by them, tations. Having learnt, from expe. notwithstanding the malignity of rience, that the silk-worms love their effluvium when shut up in a cleanliness and a pure air, they take close place. Is not the mephitic some careaboutit, and mean, by the gas a poison when breathed, and a perfume of the flowers, to correct the remedy when mixed with water: above-mentioned bad smells.
It is, therefore, to be wished that Fumigations are likewise much in all the mulberries, not only those vogue with these people, and each that are ripe, but those likewise that varies them according to their taste are young and green, an abundance and fancy; the following are those of which insinuate themselves in which they placemost confidence, amongst the leaves, should be careand to which the preference is gi- fully taken away;their ipsipid, and ven by them, gunpowder, incense, at the same time strong, smell anrosin, juniperberry, lavender, vin- nounces abundant exhalations; and egar, apple-parings, sugar, ham, and their watery particles accelerate the lard: all these fumigations, lavished fermentation of the litter. I feel without any order or method, serve the difficulty that must attend the only to spoil or to load the air, separating of them when small. and should be banished, to the when the demand for the quantity reserve of one only, on which we ofleaves is considerable; but the shall treat hereafter.
pains must in that case beredouble Fruits being at least of as perni- and done must be left to remain cious a quality as flowers, should be that approaches to being ripe. equally kept at a distancc from the Before the modern discoveries place where the silk-worms are; the made on the different sorts of gas, trunks and chests of drawers of the it was not doubted but that in these peasants are never unprovided with hidden springs consisted the prinsuch articles; apples above all ciples of sickness or of health; and others, the smell of which is in ge- although we have bere given but a neral so disgustful, is to them a rapid sketch of this, relatively to
the silk-worms, those persons who In the mineral kingdom, the first are not versed in these matters have impression of fire, or the first degree nevertheless seen enough to be con- of calcination, developes a blue covinced that the different kinds of lour, sometimes interspersed with gas may happily, in many cases, be yellow, as is observable when lead, rendered profitable. There is even tin, copper, iron, or other metals, room to hope, since so many esti-' are exposed in a state of fusion to mable learned men employ them. the action of the air, to basten their selves in researches on the nature cooling. This may be especially and quality of air, that new disco. observed in steel plates which are veries will not fail to succeed those coloured blue by heating. already made. *
Metals acquire the property of reflecting the yellow colour by com
bining with a greater quantity of On the influence of oxygène on co- oxygène ; and accordingly we per
lours; from Nicholson's Trans ceive this colour in most of them, lation of Chaptal's Chymistry. in proportion as the calcination ada
vances. Massicot, litharge, ochre, YOLOURS are all formed in orpiment, and yellow precipitate, Che which bodies possess of absorbing A stronger combination of oxysome rays, and reflecting others, gène appears to produce the red; forms the various tinges of colours whence we obtain minium, coleowith which they are decorated, as thar red precipitate, &c. is proved from the experiments of This process is not uniform Newton.-But in what manner do through all the bodies of the mine.' the coloured bodies of the three ral kingdom ; for it is natural to in.' kingdoms of nature accqire thepro- fer that the effects must be modifi. perty of constantly reflecting one ed by the nature of the base with determined kind of rays? This is a which the oxygène combines. Thus very delicate question; for the elu- it is that in some of them we perceive cidation of which I shall bring 10. the blue colour almost immediately gether a few facts.
followed by a black; which may. It appears that the three colours easily be accounted for, on the conwhich are the most eminently pri- sideration that there is a very slight mitive,--the only colours to which difference between the property of
pay attention, that is to reflecting the weakest rays, and say, the blue, the yellow, and the that of reflecting none at all. red--are developed in the bodies To give additional force to the of the three kingdoms, by a greater observations here made, we may or less absorption of oxygène, which also take notice, that the metals combines with the various princi- themselves are'most of them colourples of those bodies.
less, and become coloured by cal
cination; •While the most respectable societies of this kingdom shew, by their premiums, that they think the encouragement of silk an important object in British agriculture, it is right to bring forward every information likely to elucidate the subject: with these views we insert the above paper, which, in our opinion, offers no trivial reasons for showing how questionable must be this culture.
cination ; that is to say, by the of the red colours; and that a very fixation and combination of oxy. highly charged metallicoxideis used gène.
as the mordant for scarlet. The effects of the combination of We find the same colours deveoxygène are equally evident in the loped in the animal kingdom, by the, vegetable as in the mineral king- combination of the same principle. dom ; and in order to convince our- When flesh meat putrifies, the first selves of this, we need only follow impression of the oxygène consists: the operations in the method of pre- in producing a blue colour; whence paring and developing the princi- the blue appearance of mortificapal colours, such as indigo, pastel tions, of flesh becoming putrid, of woad, turnsole, &c. We likewise game too long kept.- This blue coobserve, that the first degree of com. lour is succeeded by red, as is obbination of oxygène with oil (in served in the preparation of cheeses, combustion) developes the blue co-which become covered with a moul. lour for the instant. »
diness at first of a blue colour, but The blue colour is formed in dead afterwards becoming red. vegetables only by fermentation. All the phenomena of the combi. Now in these cases there is a fixa- nation of air with the several printion of oxygène. This oxygène ciples in different proportions may combines with the fecula in indigo, be observed in the flame of bodies with an extractive principle in turn- actuallyon fire. This flame is blue sole, &c.; and most colours are when the combustion is slow; red, likewise susceptible of being con- when stronger and more complete ; verted into red by a greater quan“ aud white, when still more pertity of oxygène. Thus it is that fect. turnsole reddens by exposure to
From the foregoing facts, we may air, or to the action of acids : be- conclude that the blue ray is the cause the acid is decomposed upon weakest, and is consequently rethe mucilage, which is the recept- flected by the first combination of acle of the colour; as may be seen oxygène. We may add the followin
syrup of violets, upon which ing fact to those we have already the acids are decomposed when exhibited. The colour of the atconcentrated. The same thing mosphere is blueish, the light of the does not happen when a fecula is stars is blue, as M. Mariotte has saturated with oxygène, and does proved, in the year 1678, by renot admit of the decomposition ceiving the light of the moon upon of the acid. Hence it is that in- white paper: the light of a clear digo does not become red by acids, day reflected into the shadebysnowi but is, on the contrary, soluble in is of a fine blue, according to them. It is likewise, for the same the observations of Daniel Major reason, that we observe a red co. Ephem. des Curios, de la Nature, lour developed in vegetables in 1671. which an, acid continually acts, as in the leaves of the oxalis, of the virgin vine, the common sorrel, and Account of a spinning limar, or slug. the ordinary vine. Hence also it By Mr. Thomas Hoy,
of Gordonhappens, that acids brighten most Castle, associate of the Linnean So.
from the Transactions of the four feet below the branch from Linnean Society.
which it was suspended, and at the
distance of four feet and a half from T is well known that several in
; to which was ap
gradually of an caterpillars of many species of inch in about three minutes, slower moths, can convey themselves safely considerably than its ordinary mothrough the air, without wings, bý tion, either upon the ground, or means of silk lines or threads spun even in ascending the trunk of a out of their own body: but it has not tree; not so slow, however, as one been observed (as far as I know) that would expect, if it is considered any species, arranged under Lin- that a slug is not furnished, like the næus's class of vermes, is possessed insects above-mentioned, with a of a similar power of self-convey- particular reservoir of glutinous lie ance. An instance occurred to me, quid, from which the silk lines are about a yearago, which leaves meno spontaneously and almost instantaroom to doubt but that some of them neously emitted; but that the line, can convey themselves at least down.
by which it descends, is drawn from wards from a considerable height, in that slimy glutinous exudation grathat manner. In going through a dually secreted from its pores, and plantation of Scotch firs, I observed covering its whole body. It seemed something hanging from abranch of to require a great degree of exerone of them, at a little distance. As tion in the animal to produce a it seemed to be larger than any ca- continued supply of this liquid, and terpillar of the tribes Geometræ or to make it flow towards its tail. Tortrices, that I was acquainted For this end it alternately pushed with, it attracted my particular no out its head, and drew it back again tice. When I approached it, I below its shield ; turned it as far as found it to be a snail, or rather possible, first to one side and then slug ;* and, at first, supposed that to the other, as if thereby to press it had been shaken from the tree by its sides, and so to promote the se. wind, after having been entangled cretion. This motion of the head in a spider's web, or among the silk in a horizontal direction to one side, lines of some caterpillar. Upon made its whole body turn round; observing it, however, more atten- whereby the line by which it hung tively, it was hanging by one line was necessarily twisted, and from only, which was attached to its tail. being flat became round. Besides, This lioe or thread, at the distance it might perhaps tend to draw off of one inch and a half from the the glutinous matter, and thus animal, appeared to be as fine as lengthen the line; which could those spun by the Aranea diadema, scarcely be effected merely by the - but nearer to its body it was thicker; weight of the slug, although that and, at its junction to the tail, was was pretty considerable, being bebroad and flat, exactly correspon- tween sixteen and seventeen ing to the tail itself. The slug was grains.
This slug seemed to be of a spe uncommon spectacle, which I at oies between the Limar agrestis first took for a caterpillar hanging and flavus. Lino. Its specific cha- by its thread, and reaching to within racter might be,
a foot of the ground, and therefore
I did not much regard it ; till on a LINAX (filans) cinereus margine flavo. nearer view 1 perceived it, to my Perhaps the shade of the fir-trees, abour three quarters of an inch in
great surprize, to be a small slug, and the wet foggy weather, when I length. It hung by the extremity observed it, may have rendered the of its tail, and gradually descended
Limax flavus of a paler colour; till it almost touched the ground, therefore I cannot pretend abso- when I shook it off with my finger. lutely to introduce ibis, as a new The thread seemed to issue from the species, to the acquaintance of the body of the animal; yet I never obLinnean Society. But if the fore
served a second or a former instance going account exhibits a new in- of any kind of snail having the faStinct, or something that has not culty of forming a thread. been heretofore observed in the animal economy, it may perhaps not
« GEORGE SHAW. be below the notice of a society February 6, 1791." instituted for promoting the knowledge of natural history.
ADDITIONAL NOTE, Case of hydrophobia ; with the ap-
pearances on dissection. Commu.
nicated in a letter to Samuel Foart It is considerably more than ten Simmons, M.D. F.R. S.by. John years since I had an opportunity of Ferriar, M.D.physician to the inobserving the phenomenon so ac firmary at Manchester; from Me. curately described by Mr. Hoy. dical Facts and Observations. Having never, either before or since, observed a similar appearence,
I N Friday morning, December was inclined to consider it as a cir. cumstance merely accidental; but John Johnson, recommended as a as it is thus confirmed by Mr. Hoy, home patient of the infirmary, who there seems no reason to doubt that was said to have been bitten by a the animals of the genus Limax mad dog. have a power of occasionally ma I found him in a tremulous ir. naging their glutinous excretion in ritable state, with a weak irregular such a manner as to serve the pulse, and a white tongue. His purpose of a thread in a direct eyes looked wildly; he was fearful descent.
of every unexpected noise, and
seemed to be continually on the The copy of my own memorandum watch against surprises. When in. on this subject is as follows : terrogaled respecting his com
plaints, hegavea long detail of pains September 27, 1776, in his chest, cough, and difficulty of “Sitting in an arbour, about eight breathing; but was unwilling tomenfeet high, I was amused with a very tion his dread of water. He owned