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Show '114; Of PHARMACY} Of PHARMACY." lell'en the Quantity of the Oil of Herbs,which delight in a moderate Heat with Drynefs ; and this brings the Generality of Plants to Perfection. SUBLIMATION is much the fame as Difli/lation, only the former ele. vates folid Bodies, as this laft does Liquidr, though fometimes both may be obt..iiied by One and the fame Operation. If the Mattenwhen it is fubllilled concretes into a Mafs, then it is called Suhlz'mate; if it ari- {es fomewhat in the Form of Powder it is called Flowers. The Veifels that ferve to perform this Operation are different from thofe of Difiillation; for as the Fumes offolid Bodies do not arife very high, 1:5 The common MELTING FURNACE is a hollow Cylinder with a Flew. made in the back Part, like the former, but without a Door; for the Fewel and Veilels are put in at the Top, which may be covered when there is Occafion with 3 Tile or Iron Plate, There is another Furnaoe of this Kind with a Flew or Chimney on the Top. The Furnace for a COPPER STILL not only difi‘ers in Make from the foregoing, but has a particular Contrivance to convey the Heat round all the Sides; for the Flew which is made for the Conveyance of Flame and Smoak, runs all round the Still in a {piral Manner. It begins at the farther End of a long narrow Grate, and when the Cir cumvolutions there is little Occafion for a Receiver or Cumin/or, and one Vefiel may are ended at the uppermofi Part. it difcharges the Smoak generally perform the Office of both, unlefs the Matter is extremely 'vo. mon Chimney. The ATHANOR FURNACE is defigned to keep a conftant Heat, even for a Year or longer, and has been made Ufe of to find out fopher's Stone, However, as fome chemical Operations the Philo- are very tedious, it is the heft for fuch Purpofes, there being no Occaiion to infpeé‘t the Fire but once in a Day or two. The Body of this Furnace is made ofa confiderable Height like a Tower, in order to receive a large Qiantity of Fewel at Once ; and as the Top is clofely covered, it Will only burn as it falls down to the Level ofthe Flew. As the Defign is to convey the Heat from the Body of the Furnace to a Bath on one Side ofit there is a Door which opens into a large Flew, that ferves to convey the Heat to the Sand-bath; and on the oppofite Side there is another to mfpeéi the Fire. IND FURNACES are generally nothing more than high Chimneys, through which the Air pallets with great \/ elocity in a conl'tant Stream, by‘which Means a very confiderable Degree ofHeat is excited. in this Chimney Iron Bars are placed horizontally at a convenient Diiiance from the Bottom, and above them is an iron Frame and Door, through which to convey the Fuel and Crucibles, the Part below the Bargis leftopen for the free Admittance of the Air. latile. or unlefs the Fluid rifing with it renders a depending Receiver neceilary. Thus a Mal/aft or long Via] are often fufficient. 0f CHEMICAL INSTRUMENTS. A FURNACE is a Structure defigned to hold Fire, in fuch a Manner, that it may be eafily governed and applied to the Vefiels in which the Matter intended to be changed by Fire is contained. Hence may Fur- mzre muit have a FIRE-PLACE, in which the Fire is to be kindled and kept up as long as is neceiiary. This likewife {uppofes a FLEw or Chimney, through which the Smoak may make its Exit ; an Opening to admit the Air, which is commonly the AflJ-pit; and a Door whereby to convey the Fuel for the Maintenance of the Fire. Befides it lhould be f0 contrived, that the Fire may not be burnt in vain, but directed to the Parts where it ought to exert its Force. Add to this, that a Place muil be made to receive the Vciiels expofed to the Action of the Firti that they may be there kept in a proper Heat till the Operation is performed. The molt SIMPLE FURNACE of all, called the Furnace for OPEN FinE, is commonly made of an Iron Ring or Hoop five or fix Inches deep with a Grate at the Bottom like the common Stoves, and has either Feet at the bottom, and may be removed from one Place to another, or is fixed in Brick-work, being defigned for the making of DECOC'I'XOKS and INFUSIONS. . 'l‘he SAND FURNACE is deeper than the former, the lower Part of which is built in the fame Manner as for common Coppers, in which?! cylindrical lron Pot mult be placed to contain the Sand.‘ It will be beli ifit has a Rim round the Top to hang it on the Brick-work, and may be from fix to twenty Inches in Diameter, according to the Size")f the Retorts and (Blades. or other Vclfels, that are to be placed therein: The San/{is to be put into this Pot, and thould be large and grained, that the Heat may pafs through it more freely. If there603"," is an)' little Stones in it they lhould be lifted out, left they fliould break the Glades. In the fore Part of this Furnace there is a Door, through which to convey the l-‘ewel, which fuppofes an Alli-hole to be made underneath it. in the back Part there is an Aperture or Hole made to come out near the Rim of the Pot, by which the Smoak is difcharg‘ ed into the Chimney or Flew . Th9 into a com- . Vi 1th Regard to the défiarent Heal: requii‘ite for divers Operations, it is ohlervable, that the Heat of a Hal/16.2271 Ala/"I'd", or Water-bath, is mUCh "joi'c equal than that of Sand ; for this lait, unicfs it be knot al- ‘VKYS flirting. Which is inconvenient, is much hotter at the Bottom. than 3‘ the F0}). But as Water cannot be heated beyond a certain Degree, :eiiaadzéatb will fometimes become nece'li‘ary . When Veficls arebpla~ i in immediate Contact with the burning Fuel, it is called operating M c naked F178, and this is capable of the greatclt Heat of all ilinsllifiEURj] MARIE, or a I'l'ater-batb, is when a Veli't'l which‘cons under whi hatteiiT'to be heated is placed in alr'ot filled With Water, 1 atter in :h I‘l/ ire is made, f0 that as the W ater becomes hot, to: ed by the H61 eflel will be hot too. Some Proceiies may he perform. 1 Elmer as e gof a lighted Lamp, placed under the Vei‘iel in the 11.31132 FUrnacg co un er a 'learkettle, A rerverderm‘wy ‘l'lCat ls niaiic‘ in 3. "ends u \vergd With .a Dome ; for the Heat 01' lilame, which always Halted VeIichvlarls' meeting wmi Oppoiitiori,.will be refiet‘led back on the erf to foftp aced (in two Iron Bars. A [lg/91ml 407"? may allo be mad: up or {m then tie Necks of (mail Glafs VeiTels, in Order to. cloii.‘ tiicni do to h em erinctic-ally, which is done. With red hot Wt the Ti\et;l: ofa {mall Matrafs in the Place Pinceis. A; where it is in, 1 3 . tended "‘ \‘lllfl \ -|\\ \ \"m‘ |
