Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/818

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will, on being expofed to the air, attract a new acid, and on being diftilled again, it will yield more fpirit or oil. Philof. Tranf. INK 157.

It is remarkable, that fo ftrong an acid as this mould float in the air unperceived, and exert itfelf only where proper admixtures and a proper nidus call it in. In both the cafes of nitre and vitriol divefted of their acids, the air gives the proper acid agsin ; yet in the cafe of the expofed alkali fait, no acid, but only pure water is received ; and in fome acids, as the oil of vitriol, pure water, only, is received from the air. This is evidently proved by being careful in concen- ' trating the liquor, fiift, to a certain degree of ftrength ; and then, after expofing it a proper time, diftilling away what was gained from the air. This will be found, by the fmell and tafle, to be no other than pure fimple water ; and the liquor remaining 111 the retort, when all this is driven off, will be juft as ftrong as before, and juft the" fame in quan- tity, and as ready to receive the fame particles again. The ilronger the oil of vitriol is, the more powerfully it will attract the airs humidity, and the more it will increafe in weight. Such as is perfectly dephlegmated, will increafe to more than three times its weight ; three drams of it, in an experiment of Mr. Boyle's, increafing to nine drams and thirty grains. The increafe is much quicker at firft, when it is ftrongeft, than afterwards when it is thoroughly diluted. Oil of vitriol, in the fmall quantity here mentioned, will receive eighteen grains addition at fint, in the fame fpace of time in which it will afterwards receive but two grains. The changes of moift and dry in the air alfo affect it. Philof. Tranf. 1. c.

It is remarkable, that fulphureous air makes an effervefcence with pure air. Thus if frefh air be let into a glafs veffel filled with fulphureous vapour3, arifing from a mixture of fpirit of nitre, with a vitriolic mineral, an efFervefccnce will arife, and the frefh air will be nearly abforbed -, and the air in the vefTel, which was tranfparent and clear, will be- come a reddiih turbid fume. After the effervefcence is over, the turbid air again becomes clear, but upon the admiilion of frefh air ■again b°c r ">es turbid, and the air is abforbed as before. " But af. each re-admiflion of frefh air, the quantity abforbed is lefs and lefs, 'till no more is abforbed. See Hales, Hiemaftarics, p. 280. feq.

Dr. Hales thinks, that the effervefcence arifing from the mixture of frefh air, with that which is flrongly impreg- nated with fulphureous fumes, may give rife to that irkfome heat which we feel in fummer, and is called a clofe, fultry, temperatureof air. And hence the common obfervation, that lightning cools the air feems to be well founded, as being the laft effort of this effervefcence. Hales, ib. 284, 285. ALANA gleba, a name fometimes' given to the yellowifli white

tripoli. See the article Tripoli, Cycl. and Suppl. ALATED leaf, in botany. See Leaf.

ALAUDA, (Suppl.) in ichthyology, a name ufed by fome au- thors for feveral fpecies of the fifh called blenmus. See the article Blennius, Suppl. ALAUSA, in zoology. See the article Thrissa, Suppl ALBUGO (Suppl.) — Dr. Mead tells us of feveral cures of the albugo, performed by means of an eye powder which he recommends. The receipt is thus, Take of common glafs any quantity, pound it in a mortar to a very fine powder ; then add an equal quantity of white fugar-candy, and levi- gate the mixture 'till it becomes impalpable. A little of this powder put into the eye with a quill, every day, gradually wears off the fpot.

Another method of removing the fpeck, is to have it pared by a furgeon every day with a knife : But this feems a doubtful remedy. See Monit. et Praet. Medic. Append. ALCA, in ornithology. See the article Alka, Suppl. ALCALI, ? q 1 _• 1 ( Alkaly, Suppl.

ALCALINE. \ Seetheart ' cles f Alkal.ne, Suppl. ALDER-/>w, alnus, in botany. See the article Alnus, Suppl. Berry-bearing Alder, the name of a genus of plants, called

by authors frangula. See the article Frangula, Suppl. ALDERAIMIN, or Aderaimin, in aftronomy, a fear on

the left fhoulder of the conftellation Cepheus. ALECTRUONURUS gramen, in botany, a name ufed by

fome for thefejluca of Linnaeus. See Festuca, Suppl. ALECOST, in botany, a name given by fome to a fpecies of tanzy, more ufually called cojlmary. See Tanacetum, Suppl. ALEHOOF, in botany, a name by which fome call ground- ivy. See the article Ground-/^, Suppl. ALHAGT, in botany, the name of a genus of plants, accord- ing to Tournefort; but comprehended under the hedyfurmns by Linnseus.

The characters are thefe : the flower is papilionaceous, the germen of which finally becomes a pod compofed of a great number of parts, articulating, as it were, with each other, and containing each a kidney-fhaped feed. To thefe marks it may be added, that the leaves grow in an alternate dif- pofition.

There is only one known fpecies of this genus, called ge- nijla fpartium, and genijla fpinofa, by other writers. Town. Inft. Bot. Corol. p. 54. ALHEAL, a name given to feveral plants on account of their

extraordinary virtues. See Panacea, Cycl. and Panax- Append.

ALISANDERS, in botany, a name given by fome to the fmyrnium. See the article Smyrnium, Suppl.

ALKANET, in botany. See the article Anchusa, Suppl.

ALLIARIA, in botany, the name fometimes given to a fpe- cies of hefperis, called in Englifh jack by the hedge. See the article Hesperis, Suppl.

ALLIGATOR, in zoology, the name given to the crocodile in the cold climates of America, where it does not grow to its full dimenfions. See Crocodile, Cycl. and Suppl.

AhLiGATOR-pear, in botany. See the articles Pear and Py- rus, Suppl.

ALMNOD (Suppl.) — Dzvarf Almond, a name given by fome to feveral fpecies of peaches. See the article Persica, Suppl.

Ethiopian Almond, the name of a genus of plants, called by Linnaeus brabejum. See Brabejum, Suppl.

AlNlJluxus, in medicine. See the article Diarrhoea, Cycl. and Suppl.

Alvi obflruEiio, coftivenefs, in medicine. See the article Ob- structio alvi, Suppl.

AMARACUS, in botany, a name fometimes ufed for the par- thenium. See the article Parthenium, Suppl.

AMARYLLIS, in the Linnaean fyPcem of botany, the name of a genus of plants, called in Englifh daffodil-lilly, and by other botanical writers lilio-narciffus. See the article Lilio- narcissus, Suppl.

AMBER-rn?e, in botany, the Englifh name of a genus of plants, called by Linnaeus anthofpermum. See Anthosper- mum, Append.

AMBERBEI, the name of a genus of plants, according to Vaillant, but comprehended by Linnaeus under that of cen- tauria. See the article Centauria, Append.

AMBULQN, in botany, the name by which J. Bauhinc calls

• the myrica, or fweet- willow. See the article Myrica, Append.

AMENTUM, among botanifts, the fame with catkin. See the article Catkin, Suppl.

AMGAILA. See Leucacantha, Suppl.

AMMODYTES, in zoology, the name of a fpecies of colu- ber. See the article Coluber, Append.

AMMONIACUM///, inchemilhy, &c. See the article Sai, Am?no?:iaatm, Cycl. and Suppl.

AMMOSCHISTA, in natural hiftory, a genus of ftones of a laminated ftructure, and fplitting only horizontally, or into flat plates.

The ammofchifa are coarfe, harm, and rough ftones, of a very loofe texture, and appearing fomething porous. They are considerably heavy, and compofed of a large, coarie, and obtufely angular gritt, furrounded and in part held to- gether by a loofe earthy fpar. They are very foft and fri- able in the mafs, but much more fo when reduced to fmall pieces. They make a violent effervefcence with aqua fords, and will not eafily ftrike fire with fteel.

The fpecies of ammofhijla, are thefe : r. The grey, friable, dull ammofchijlum. 2. The brownifh white, glittering am- mofchijlum. 3. The greenifh grey, mining ammofchijlum. 4. The yellowifh grey, glittering ammofchijlum. 5. The hard, purple, and white ammofchijlum. And 6. The bluifh, glit- tering flate ftone. Hill's Hift. of Foff. p. 443. feq.

AMOMUM, a name fometimes given to a fpecies of fium. See the article Sium, Suppl.

AMPHITRITE, in ichthyology, the name of a genus of fmall water animals, the characters of which are, that they are of an oblong figure, and have a great number of deep ftrix, like fo many lamellae ; and but one tentaculum, of a flender and oblong form, refembling a piece of thread. They are only a few inches long, of a tolerable firm fubftance, and have been ranked by fome authors among the urticts marines, and by others among the epipetrons. Vid. Hill t Hift. Anim. p. 91.

ANARTHRA, in the hiftory of infects, a claffical name efta- blifhed by Dr. Hill, comprehending fuch infects as have nei- ther wings nor limbs, and whole bodies are covered with a foft fkin.

To this clafs belong the feveral genera of worms and leeches* See the articles Worm and Leech, Suppl. ATSiASARCOVS fwclling. See Dropsy, Append. ANEMOSPERMOS, in botany, the name fometimes given

to the arclotis of Linnaeus. See the article Arctotis, Suppl. ANGLE (Cycl.) — In the practice of furveying, no angles of lefs than thirty degrees fhould be taken : nor fhould any be affumed but fuch as are actually meafured. See Hift. Acad. Scienc. 1740. ANGUIS jEfculapii, the name of a fpecies of coluber. Seethe

article Coluber, Append. ANIMAL (Suppl,)— AmMALftbJlances comprehend all the component parts of animals, of what ufe or intention foever they may be. See Substance, Cycl. Fojftle AxiMALfubftances, thofe found buried in the earth, at various depths, and embodied among various ftrata. Thefe are principally of four kinds : I. Sea-fhells. 2. The teeth, bony palate, and bones of fifties. 3. The bones of land animals. And 4. Complete fifnes. See the articles

Fojfilt