f- 



r^r 



I 



l\ . 





I 



J 

 •It 



I'I'I 



paft umbel ; tliey arc of a purple colour, and ap- 

 far in June, but are feldom fuccceded by feeds in 



_ngland. 



It is propagated by feeds, which fliould be fown on 



a ftady border In autumn, and when the plants are 

 ftron^ enouf^h to remove, they fhould be tranfplanted 

 on 2i%ady border where they are defigned to remain, 

 and will require no other care but to keep them clean 

 from weeds. 



The eio-hth fort grows naturally in Spain and Portu- 

 cral j this hath a great refcmblance df the fecond, but 

 the fValks do not fpread fo much ; they grow ere6t, 



mafies, are then double wedgc-lJke particles, whicli 

 have abundance of furface in refpeil to their folidity ; 

 and this is the reafon why they Avim in water, when' 

 once they are raifcd in it, although they are fpecifi- 

 cally heavier, thefe fniall points of falts getting into 

 the pores of the water, wlicreby they are, in fomc 

 meafure, fufpended in the winter, when the lieat of 

 the fun is not ordinarily ftrong enough to diflblve the 

 falts into fluid, to break their points, and to keep 

 them in perpetual motion ; which being lefs diilurbed 

 are more at liberty to approach one another, and by 

 fhootihg into chryilals, of the form above-mentioned. 



about feven or eight inches high, are ligneous and pe- I . do, by their extremities, infinuate themfelves into th 



rennial. The leaves are very narrow, and feldom 

 more than an inch long, (landing thinly upon the 

 ftalks, having no foot-ltalks. The flowers grow in 

 hemifpherical umbels on the top of the ftalks, and 

 are of a purple colour. It flowers in May and June, 

 but feldom produces good feeds here". 



pores of water, and by that means freeze it into afo- 

 lid form, called Ice. 



Monf Mariotte, in his Treatife of Hydroftatics, gives 

 the fubfequent account of what happens to water in 

 freezing, which he difcovered by the following expe- 

 riment. 



This fort may be propagated by cutfings, which i Having filled a cylindric vcfliel, of about feven or 



fliould be treated in the fame way is 'is before di- 

 re(3ted for the firft fort ; and fome of the plants may 

 be planted on a warm border in a dry foil, where they 

 will endure the cold of our ordinary winters very well j 



eight inches high, and fix inches diameter, within tv/o 

 Inches of the top, with cold water, he expofed it to 

 the open air in a great froft, and obferved exadlly the 

 whole progrefs of the freezing of it. 



k t 



I V ^ * ^ 



but it will be proper to nave two or three plants in j The firft congelation was in the upper furface of the 

 pots, which may ce fheltered under a frame in win- 

 ter, to preferve the kind, if, by fevere froft, thofe in 

 the open air fl:iould be deftroyed. 



IBISCUS. ; See Hibiscus. 



ICACO. See Chyrsobalanus. 



ICE is a hard tfanlparerit body, formed from fome 

 liquor congealed, of fiked. " \' " 

 Ice is faid to be th6 natural ftate of water, which re- 

 gains firm, 'and not liquid, when no external caufe 



' afts upon it. " • - • 

 The true caufe of the congelation of water into Ice, 

 iecm's to be the introduftion of frigorific particles into 



'■ the pores bf intefftices between the particles of wa- 



' ^f\ and by that means getting fo near them, as to 



■ be juft within the fpheres of one another's attrac- 

 tions, and then they muft cohere info one folid or 

 firm body. 



w^ter, in little long water Ihoots, or laminae, which 

 were jagged like a faw, the water between them re- 

 maining ftill unfrozen, though the reft of the furface 

 was already frozen to the thicknefs of more than two 

 lines i he obferved that leveral bubbles of air were 

 formed in the Ice, that began to fix on the bottom 

 and fides of the veflTel, ibme would rife up, and others 

 remained entangled in the Ice, which made him ima- 

 gine that thefe bubbles taking up more fpace in the 

 water, tKah when their matter was, as it were, dif- 

 folved in it, they puflied up a little water through 

 the hole at the top, after the fame manner that new 

 , wine works out at the bung-hole of a veflel when it 

 begins to heat, and the little water that ouzed out at 

 this little hole in the Ice, fpread ing itfelf upon the 

 upper furface of the watei-, which was already frozen, 

 became Ice alfo, and there Began to form a hill of 



It mdy be wondered why Ice goes to the top of the I Ice j and that hole continuing open, by reafon of the 



water which paflTed fuccefHvely through it, being 

 puflied up by the new bubbles which formed them- 

 felves in the Ice, which continue to increafe about 

 the fides and bottoni of the veflTel, he obferved that 

 the upper furface of the water was frozen above an 

 inch thick towards the edges, of the veflel, and 

 above an inch and a half round about the little 

 ole, before tne water that was contamed in it. as 

 m a pipe, became frozen, out at laft it was frozen ; 

 fheh the middle of 'tlie wafer re unfrozen, 



' Wat^, ivheh it is frbzefi into !(!&, fakeS tip naore | and the water which was compreflTed by the new 



bubbles, which formed themfelves for two. or three 

 hours, jhaving no vent at the little hole, the Ice broke 

 at once towards the top, by the Ipring of the in- 

 cluded 



Vrater, foifone would imagine, that being colder than 



flowing water, it ought to be more condenfed, and 



' confecjuently heavier •, but is to be confidered^ that 



' there are always fome bubbles of air ihtertpe'rfed in 



Ide>*- It is certain, by the fwifnfriirig' of Ice iipbh wa- 



' tcr, that it is fpecifically lighter than the water out of 



, which it is made by freezing; and it is. as certain, 



■ that this lightnefs of Ice proceeds from thofe nu- 



tf ^aflfl. M 4* VA'4 ' ~~ 



merous bubbles that are produced in it by conge- 



^ 



/^' i: 



ip nr 

 ft is 



VI- 



l fpace than it did before it was congealed. 



^ fible, that the dimenfions of water are increafed by 

 freezing^ its particles being kept at forne diftance 

 the one from the otiierl by the intervention of tfie 



frigorific rnifter. - ■ - ' '" ' "^ ^ ^ '^ ' 



And, befides, thSre are many little voliiriids bf air 

 included at feveral diftaric^s, both in the pores of the 



' Watery particles, and in the interftices made by the 

 Jpherical figures. Now, by ttie infinuation' of thefe 



" chryftals, the volumes of air are driven out of the 



' watery particles, an^ many bf diem uriifihg, 'form 

 larger volumes -, thefe have thereby a greater force 

 to expand themfelves than when they are difperfed, 



. and fo both enlarge their dimenfio^ns, and lefleh the 

 ftecific gravity of water thus congealed into Ice. 

 It feems very probable, that cold, arid freezing, arid 



. confccjuently Ice, are produced by fome fubftancebf a 

 fahne nature floating in the air; in that falts; arid 

 ^ore eminently foriie particular ones, when mixed 

 ^ith Ice or fnow, do wonderfully increafe the force 

 ahdeffeftsofcold. 



It is alfo yifible, that all faline bodies caufe a ftiff- 

 nefs and frigidity in thofe bodies into which they 



enter. 



. -1^ is manifeft, bf obfervirig" falts by microfcdpes, 

 , that the figures of fome falts, before they Ihobt into 



4 



air. 



- * -^ 



In like' manner the froft a6ls upon vegetables, by 

 thefe frigorific particles entering the tender fhoots of 

 plants, and infinuating between the pores of the fap, 

 thereby increafing its bulk, fo that the tender veflrls of 

 the plants arc torn, and thofe parts of the plants are 

 Ibbn killed ; arid' if he greater the quantity of moifturc 

 is in vegetables, fhfe more they are in danger of be- 

 irig"deftr6yed, for we frequently fee many plants which 

 grow on the top, and from the joints of walls, efcapc 

 the fevereftTrofts, when thofe of the fame kinds are 

 all, deftroyed which were iri'the ground •, which is en- 

 tirely owing to tlieir vcfl^els being ftronger and more 

 c6mpa£F, arid riot fd replefe with moifture : 

 the auturiin proves' cold and moift, whereby the vef- 

 felsof plants are not properly hardened, and are re- 

 plete with moifture, a fmall froft will do great mif- 

 chief to them ; whereas when the autumn is dry and 



- warm, the tender Ihoots of trees and Ihrubs are har- 

 dened, .and drained of their moifture, fo are not lia- 

 ble to the like acciderils. ... 



I C E-H O U S E is a building contrived to preferVC ice 



fp when 



for the ufe of a family in the fummcr fealon. 



-Thcfc 



