Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/883

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tcr of the earth's orbit has no fenfible proportion to it. 2. That the angle F E G (Fig. 2.) in the abovementioned trian- gle, is 20 " a ; and confequentiy that the ratio of E G to F G, or the velocity of the Light to the velocity of the earth in its orbit, as io2roto 1 ; whence it follows that the Light. comes from the fun to us in eight minutes and an half. 3. That the Light proceeds with the fame velocity from all the itars ; for all have the fame angle F E G. Whence, (if we fuppofe that all the flars are not equally diftant from us, as many' arguments prove) it will follow, that the motion of Light, all the way it paffes through the immenfe fpace, above our atmofpnere, is ^equable or uniform. 4. Laftly It muft be confidered, that very fmall differences cannot be perceived ; and no body will deny, but that in meafuring a fmall angle, an error of a fecond may be committed, what- ever care is ufed to prevent it ; and therefore, although we have faid, that the firft caule is to be rejected, we do not de- ny that the ftars may poflibly by its influence defcribe a minute circle whofe diameter is 1 ", or even a little more. s'Gravefande Phyf. Elem. Math. L 2. c. r. p. 709. feq. Hence it appears, that the fucceffive propagation of Light will caufe an aberration in the appearances of the ftars, planets, and comets. After Mr. Bradley had difcovered this caufe of error in the apparent places of the fixed ftars, Mr. Clairaut and others b , iuveftigated feveral rules for the computation of this aberration. Mr. Euler c alfo has lately given us a paper on this fubject. — [ a Mem. Acad. Scienc. 17. — b Mr. Simpfon, in hisEflays. — c Mem. deL'Acadcm. de Berlin, Tom. 2. Pp. 141, feq.] LiGNUMFJn^j tne wood of a genus of trees, called by bo- tanifts Thuya. See the article Thuya, Suppl. Lignum J/ittf is much valued by turners; making extremely beautiful cups, bowls, boxes, and other curiofities. Ruft. Diet, in voc.

LILLY (Suppl)— Afphodel-'Liti.Y, B 'ell 'a donna Lilly, Daf- fodd-h ILLY, Guernfey-Ll 1. L Y, Mexkan-LlhLY , japan- Lilly, names ufed by different authors for the Amaryllis, or LHHo-Narcijfus of Linnaeus and Tournefort. See the ar- ticle Lilio-Narcissus, Suppl.

Lilly -Dajfodel, a name fometimes given to a genus of plants, known among authors by that of Pancratium. See the article Pancratium, Append.

Day-LiLLY, a name fometimes ufed for the Ucmerocallis of bo- tanifts. See the article Hemerocallis, Suppl.

Uyacinth-hiLLY, in botany, a name given by fome writ- ers to the Se'ttla, or LUlio-Hyacinthus, of botanifls. See the article Lillio-Hyacinthus, Suppl. and Scill a, Jppend.

May-LiLLY, the name by which fome call the Convallaria of Linnasus, a large genus of plants, comprehending the Lilli- um-Convallium, Polygonatum, &c. of other writers. Seethe article Convallaria, Append.

Perjtan-LihhY, a name fometimes given to the Fritillaria, a diftinct genus of plants. Seethe artlcleFRixiLLARiA, Suppl.

Super b-L.ii.LY, the Engfifh name of a diftinct genus of plants, called byL'nmxusGloriofa. See the articleGLORiosA,^/^.

Water-LiLLY, JSlymphtsa, in botany, the name of a genus of plants. Seethe article NYMPHiEA, Suppl.

LIMAX, in the hiftory of infects, the name of a genus of thefe animals, comprehending all the naked mails, See the article Snail, Suppl.

, The body of the Limax is of a figure approaching to cylin- dric, and is perforated at the fide ; the tentacula are four in number, and two of them have the appearance of eyes. Of this genus authors enumerate the following fpecies : 1. The black naked Snail. 2. The red naked Snail. 3. The yellow one,- called the Jmher Sfia'd, variegated with fpots of agreyifh colour. 4. The very large grey Limax, fpotted with a dufky- brown. 5. The little fhort and thick grey Limax, without fpots. 6. The fmooth-bodied, reddifh-brown Limax. 7. The fmall dufky-brown, furrow'd Limax. 8. The deep chocolate- coloured Limax. Hill, Hift. Anim. p. 87.

LIME (Cycl.) — LiME-water. It appears now from the in- genious Dr. Alfton's experiments, that one part of quick Lime is fufficient for five or fix hundred parts of water. Wa- ter will dilTolve but a certain portion of quick Lime ; and how much that is cannot be eafily afcertained. So far feerm certain from Dr. Alfton's experiments, that one pound of quick Lime is fufficient for making fix hundred pounds of good Lime water ; and that thofe who with Charas have fup- pofed, that the fecond and third Lime-water is weaker than the firft, have been led into error by the fmall quantity of water they ufed. And it has been generally believed, that in order to obtain good Lime-water, the quick Lime muft not only be recent, and fully calcined, but alfo for one part of quick Lime only eight, ten, or at moft twelve parts of water taken ; as if it could impregnate no more. But the Doctor fays he has found V/ many experiments, that it is altogether indifferent whether the water be hot or cold, poured on gra- dually, or at once, the water poured on the Lime, or the Lime thrown into the water; whether the quick Lime be in fhells, or flaked ; or even expofed to the air for feveral months, for fuch quantities of the water as are commonly ufed ; and if the quick Lime be frefh, whether for one pound of it, ei^ht, ten, twenty, fifty, or five hundred pounds of water betaken. Oiily it is neceflary, even for the firft water after the ebulli-

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tion is over, to- ftir and mix the Lime with the water, and allow it time to impregnate itfelf; which is beft known by the cruft formed on its furface. FUtration indeed is not necefla- ry, if it be not to prevent any undiilolved Lime being mixed with it; or emits diminifhing its tranfparency. The Doctor, for his own ufe, poured about eight pounds of boiling water upon a pound of ftone quick Lime in a glazed earthen veitel. He drank about a pint and an half of this Lime-water, daily for about fixteen months ; filling up the veflsl, when neceflary, with frefh water, fometimes hot, and fometimes cold, without obferving any difference in the Lime- water, which he conftantly filter' d through grey paper, be- fore he drank it. He obferved, that the Lime was not ex- hausted after two years and two months, nor was the water fenhbly weaker, when it flood a fufficient time on the Lime, which he knew by the crufts that were formed. But ths Lhne becoming confidently lighter, after it is long thus ufed, it at length requires feveral days to fubfide, and form the crufts, and after the crufts are formed, it dues not leave half the water clear, as it did at firft. On the whole, this fingle pound of Lime afforded the Dodor about fix hundred pounds of Lime-water. He adds, that having taken Lime-iuater made indifferently of Limc-fW, or of Chalk, or of Shells, and fometimes made of all the three together, he was never able to difcover any difference in their effects. But fo much Lime-water is not to be obtained from quick-lime, unlefs it be frefh, completely calcined, and free from heterogeneous fub- ftances ; for if defective in any of thefe, it will yield propor- tionably lefs Lime-water.

Lime-water, which was long looked on as a cauftic, was, in the laft century, found to be a very fafe and valuable reme- dy. It is uncertain who firft ventured to give it inwardly ; but Willis, Bates, and Morct&n feem to have ufed it much. Lime-water kills worms, and many other, if not all, infects ; hence Dr. Alfton concludes it might prove a good anthelmintic fc* children, and experience has confirmed this nqtion. It is probable, that Lime-water may be of great ui'c in long fea voyages, in preventing the corruption of water, or infects breeding in it, as well as curing the difeafes to which fea- faring people are molt fubject. The experiment is certainly fafe, eafy, and attended with no expence; one pound of frefh well-burnt quick-lime of any kind, being enough for a hog- fhead of water, which may not only be ufed for common drink by the difeafed, or for prevention by the healthy ; but alfo by boiling and expofing it to the air for a fhort time, ic may be reduced to fweet water, and ufed in dreffing the victu- als of the moft delicate.

The virtues of Lime-water do not depend on its abforbency ; and it may asjuftly be called antalcaline, as antacid. Lime-water prevents or long protracts the putrefaction of ani- mal fubftances. Dr. Alfton alfo thinks that quick-lime in a ftiip's well, would effectually prevent the corruption of the water, and confequently the putrid fleams, or foul air thence arifing, which fometimes prove fatal to the crew. The virtues of Lime-water outwardly applied in many difeafes of the fkin, in excoriations, ulcers, gangrenes, &c. are well known. Perhaps there is not a better gargarifm for feveral forts of fores in the mouth and throat, than Lime-water. It has alfo been known to be of great ufe in the tooth-ach. In- wardly taken, Lime-water has all the virtues of the pure element, which are not a few ; and on which probably depend the good ef- fects of mineral waters, more than on the minerals they contain. Dr. Alfton never found it caufed thirft ; on the contrary, he found it quenched thirft, as well as iimple-watsr, and cuitom rendered it agreeable. Lime-water is notably detergent and attenuating, even more fo than foap itfelf, of mucous, vif- cid, and other animal fordes, which makes it preferable, in many cafes, to the pureft, as well as to mineral waters. In a word, Lime-zuater may be faid, in general, to purify the blood, with as good reafon, as anyone medicine whatever, efpecially from any putrid, purulent, or fcorbutic foulnefs. That Lime-water is lithontriptic has been fhewn fufficiently by Dr. Hales, and more fully by Dr. Whytt ; and this has been further confirmed by Dr. Alfton, who has fhewn the efficacy of Lime-water in this refpect, not only when made by the firft infufion, and afiifted by artificial heat ; but even after fifty or more infufions, and in the common air. The Doctor thinks that the energy of Lime-water in this cafe pro- bably confifts in its penetrating detergency, whereby mfinu- ating itfelf among the folid parts of the calculi,, or into their pores, it feparates them, or diminifhes their cohefion, but does not diffolve them.

Since there is but a fmall proportion of LJme in the water, it may be thought that taking a few grains of the quick- lime in fubftance would prove much more effectual in the Stone, than large quantities of Lime-water. But this is a miftake ; and hence Mrs. Stephens's egg-fhells and fnail- fhells, if burnt to quick-lime, can never be equally fuccefsful with Lime-water for the Stone.

As for the aques benediSles compofttes, or compound Lime-waters, they are not to be compared with Ample Lime-water in the gravel ; nor, in Dr. Alfton's opinion, in any difeafe requiring this water.

The Doctor adds, in his Appendix, that though he cannot yet determine how far Lime-water may be proper, even in

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