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as well as the water, and damages the whole, by taking off
- what ought to be the moft carefully preferved. The fpiri-
tuous part is the life or all fermented liquors, it keeps the whole together, and in a manner embalms and renders them durable and not fubjcfl to corruption ; it alfo in a great mea- sure gives them that aromatic lefrefhing and reftorative vir- tue, and the heft effects they have on the human body. Nor is this all, but the intimate and lubtil union of this fpirituous part with the reft, is perfectly the fole and entire caufe of both the former effects, fo that it by no means fuffices to have the fpirit barely prefent among the other parrs, for then it might be drawn off and poured back again, without any damage to the wine ; but the effential union is here diffolved by taking it away, and can never be reftored again by a fimple reafrufton.
- Tis therefore deftruflive of the end propofed, thus to break
and difibive the texture of the wine, and this entirely fubverts and deftroys its nature. This inevitably proves the cafe, whenever wine is evaporated or diftilled, which confbntly requires a degree of heat capable of railing water into vapour, and hence the fpirituous part being greatly lighter than the aqueom, flies off together with it, or before it, and the wine is left diffolved in its texture, and without its foul. Upon this, the remaining feline undtuous mafs is fo di.fturbed, as no longer to remain connected, but it becomes thick ;tnd turbid, and afterwards runs impetuoufly into a kind of corruption, at- tended with acidity and ropynefs. All thefe circumftances fhew, that tlio* the condenfing of wines by taking away their iupcrfluous humidity would be a very defirable thing, yet it is by no means to be done by evaporation.
FERMENTING. In the fermenting of malt for the diftilling the fpirit, the meal of unmalted corn is found neccflary to be mixed with the malt,to prevent itsavcr fermenting, and throwing off the matter of the fpirit; but asdifpatch is required in this cafe, agood quantity of yeaft is added to quicken the fermentation, (b that it may be finifhed in two or three days. More yeaft is to be added if the weather be cold, and lefs if it be hot : the reverfe of this is to be understood of meal, more of which, is to be added in hot weather to check, and lefs in cold to haften the opera- tion, which in the prefent cafe is defigncd to be violent, con- trary to .vhat ought to be obferved in the fermentation of wines, wb^re the flower the operation is performed, the better the liquor will prove, and this may indeed hold here alfo in a lefs degree, for it is poflible to ferment the warn fo violently, that it ftiall foon end in putrefaction. Shaw's Lectures, p. 216.
FERN, Filix, in botany. See Filix.
The feeds of the leveral fpecies of fern were wholly unknown to the antients. Swammerdam in his Biblia Natura, claims to himfelf the honour of having firft difcovered them; but it appears from Hook's works, that Dr. William Cole fent an account of the feeds of feveral of the plants of this kind to that author, in 1669, whereas Swammerdam declares his difcovery of them, to have been in 1673; fo that it is plain that Dr. Cole's was prior to his by fome years. Swam- merdam is an author of that ftri6t probity, that there is no room to doubt, but that he fpoke what he thought to be true; and it is even poflible, that he might have difcovered them fooner than the time he mentions; but. however that be, it ap- pears from the later obfervations of the ingenious Dr, Miles, that his accounts are extremely accurate, and juft. The fceti- veffels of the common fern, the Englifh and foreign maiden- hairs, the wall-rue, harts-tongue and the like plants, are all alike in their general form, their only differences being in the fize, and in their arrangement on the plants. The number or quantity of the feeds is very different in different plants, but Mr. Miles obferves, that the fewer feeds there are in any fpecies, there is always the more in quantity of a fort of fpun- gy or. fungous matter, which forms a kind of tubercle, not unaptly rcfembling what is called jews-ears, which feems a fubftance intended for the fheltering the feeds. In the female fern and Englifh maidenhair, the whole furface of the leaf on the under fide, feems covered with a congeries of ieeds, fo that they guard one another, and therefore have lefs occafi- on for a covering of fungous matter of this kind ; vet even on thefe plants when the feeds are fallen off", there are found fmall membranes, a little curled, looking as if they had been raifed with the edge of a fine penknife, from the skin of the leaf, not unlike the pieces of skin that are raifed off from the hand, in the trying a penknife or other fharp inftrument. In the common male fern, there are found at the proper fea- ibn, feveral brown fpots placed in a regular manner ; thefe are of a pale brown colour, and are principally compofed of this fungous matter, the feed-veffels being fmall and inferted round it. Phil. Tranf. N°. 461. p. 774. Thefe feed-veffels confift of a ftalk by which they are infert- ed into the leaf; this reprefents an elaftic cord, and is fur- rounded by a great number of annular ribs, refembling the cartilages of the afpera arteria, and indeed nothing in nature fo exactly refembles this cord or ftalk, as the wind-pipe of a fmall bird. This cord, encircles the globular membranous pod wherein the feed lies, adhering to it, and dividing it into two hemifpheres. See Tab. of microfcopical Objects, CUfs 2. The pod is compofed of a fine whitifii membrane, fomewhat
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like that which lines the infide of a pea-fhcll ; the feeds are irregular in fhape, and of a reticulated furface. The moft advantageous way of viewing this is to ufe the common microfcope for opake objeas, putting on a fmall magnifier and laying the feeds with their capfules, &c. as taken from the back of the plant, on a piece of polifhcd ivory. The prone time of the year is in the beginning of September, and then if the plant be newly gathered, the feed-veflels often burft while they are under infpeclion, and fhew a very elegant an pearance. The manner of this burfting of the pod, which is the method nature has taken for the (tattering and difperiinj of the feed, is this ; the cord becomes extended in fome one part, and feon after breaks afunder, this by expanding burfls the pod into two parts, and by continuing to expand itfell as it departs from a curve, and approaches to a right line, it rends itfelf away from the globular pod, till it be at length wholly difengaged from it ; and then,as there can be no farther refiftao.ee given to its expanding, it fuddenly flies off, and with a fort of jerk, becomes quite ftrait at once. By this laft aBion the cap- fules are fhook, and the feeds are dilcharged out of them on the plate of ivory, in the fame manner as the grains of wheat or barley, would be thrown out of a bowl placed on a table, by the fhaking of the bowl. This is a beautiful phenomenon in the minute feed-veffel of the fern, and is frequently feen when the leeds are frefh gathered, as then the cords and cap- fules are green and juicy, and the burffing goes on gradually ; but when they are dry and crifp, there is nothing of this feen' for the burfting is inftantaneous, and the feeds are toiled fo far by it, that none of them fall within the area taken in by the lens. When the pod and cord are but juft ripened, they fometimes are twenty minutes in burfting, and the whole method of the procefs, is then diftinflly and beautifully feen. This whole mecbanifm would be feen in a much more pcrfaft and beautiful manner, if it were pofiible to get off the feed- veffels from the leaves without injuring them in doing it j for the common way of getting them off, is by rubbing the leaves, and this muft neceflarily burft a great number of them ; in this method they are feen to fly off from the leaves in form of a fine duftor powder, and often get into the pores of the skin and become as troublefome as cow-itch. Phdofoph Tranf N«. 461. p. 78a ' '
Fern, in husbandry. The common female fern is a very mif- chievous and troublefome weed to the farmers, being very dif- ficult to deftroy, where it has any depth of ground to root in. Its root will often penetrate to eight foot deep, and (pleading a great way, they will rife again to the furface, and fend up new plants at a confiderable diftance. In grafs land the beft way of deftroying it, is mowing the grafs, three times a year in Spring, in May, and in Auguft.. Dung and afhes are very good manure for lands which abound with it, but the beft of all things for deftroying it, is urine. Fern cut up when the fap is in it, and laid to rot upon the ground, is a very good manure for land, and will mellow it fo as to prevent its bind- ing. Trees planted where fern grows, are obferved to thrive very much, even tho' it be upon a hot gravel ; the reafon of this is, that the fern {hades the roots, and keeps them moid: and cool. Msrtimer*& Husbandry, p. 316. The poor people in many parts of the north of England, ufe afhes of fern inftead of (bap, for warning their clothes; they cut the plant green, and then burn it to afhes, and make them. up into balls with water ; they dry thefe in the fun, and keep them ready for ufe. Scotch fheep put into a land where there is much fern growing among the grafs, generally deftroy it in a little time, partly by their dung and urine, and partly by treading it down.
Ferns, in medicine. All the fpecies of fern, and other vegetables, which carry their feeds on the back of their leaves, as moon- wort, and the like plants, poffefs the fame general virtues of drying and ftrengthening the vifcera, efpecially the fpleen.
Dwarf Vzrw. See Fjlicula.
FzRti-aJhes. The allies of the common female fern produce a very fingular phenomenon in the common way of tieatine them and their fait. If a large quantity of thefeafh.es are pro" cured, and the fait to the quantity of feveral pounds extract- ed from them in the common way, it will fucceed better than in fmaller quantities. The greater part of this fait bein<* dried, if the remainder, which is more moift, be expofed to the air to receive fome of the vapours of it, this will foon become fluid, or an oil, as it is very improperly called by deliquium. The reft of the lixivium, which will be very heavy, and of a deep blood-red, or claret-colour, being fet by in a glafs veiled unftopped for five or fix months, there wilf be found at the bottom of the liquor, a very large quantity of fait precipita- ted to the thicknefs of about two inches of the bottom of the vefl'el. The lower part of this will have all the foulnefs, and appear difcoloured ; but the upper part will be extremely pure and white. From the furface of this part, there will grow up a number of plants, in appearance (landing erect, and at fmall diftances from one another. Thefe are only the laft crys- tallizations of the fubliding or feparating fait, but they have a regularity that is very furprifing, they vary conliderably in fize and weight, but axe all of the fame fhape, exaflly re- fembling
