Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/531

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length of the worm, a coarfe and naufeous oil, which will give a difagreeable flavour to a very large quantity of pure fpirit.

When the worm is once infected with this oil, it penetrates fo deep into the pores of the metal, that a Ample wafhing will not get it out, but rather it ought to be filled with a lixivium boiling hot, or elfe fome pure and highly-rcflified fpirit fhould be put into it, and left in it a whole night, to imbibe and carry off with it the oil. Thc-fe are cautions that may feem trifling, but they are in reality of fo much confequence, that if rightly attended to, a much purer fpirit will be drawn off this way, than by any other common me- thod. Sbaui's Effay on Diftillery.

Proof Spirits, or common faleable goods, are fpirits of any kind of a determinate ftrength, being the fame with that of good brandy, and the malt and tasru fpirits of thediftillery, as they are ufually fold ; containing equal quantities of recTified fpirit and water. The common method of examining whether fpirits have

■ this due degree of ftrength is this. Take a long vial, fill it half way with the common malt fpirit, and "give it a fmart ftroak by its bottom againft the palm of the hand, there will then appear on the furface a chapler, or crown of bubbles, which will go off again in a ftrong manner ; that is, firft remaining a while, and then going off by degrees without breaking into fmaller bubbles, or fweliing into larger.

By this experiment all the traders in fpirits judge of the ftrength of the goods they purchafe, yet this is a mere fallacy and deception ; for if only a little vinous, or faccharine matter, as treacle, fyrup, muft, rob of fruits, or the like, be added to a quantity of highly-reclined fpirit of wine^ this flight addition will give a brandy proof to that fpirit. Whether there be any I'ecret for making weaker fpirits (hew this proof, as well as brandies, &c. is not certainly known, but the thing is certainly practicable, fince arrack, which is but of half the ftrength of brandy, gives as fair a proof this way ; and if a drop or two of any effential oil be add- ed to a pint of brandy, it takes off its proof, and makes it appear much weaker than it is. The true ftrength may, however, always be known, by carefully burning away a meafured quantity of brandy, Wc. fince if it leaves one half water, it is right, if more or lefs, it is too ftrong, or too weak.

But befide the falfe method of judging of brandies by what is called proof, there is another not lefs fallacious one of judging of their goodnefs, though kept as a great fecret in the hands of fome dealers, and imagined a certain criteri- on to determine whether foreign brandies are ' mixed with corn fpirits. Thefe diftillers are provided with a certain yellow liquor, a few drops of which being poured into a glafs of right French brandy gives it a beautiful blue colour, and by the ftrength, and goodnefs of this colour, they judge and buy ; but if common malt fpirit were tinged with pak, it would give this colour equally with French" brandy, and might be purchafed as fuch. This proof-tinaure is ex-

- peditioufly made, by diffolving a little green vitriol, firft

- calcined to a rednefs in a weak fpirit of fea-felt, which thus becomes a yellow liquor, a fingle drop or two of which being added to a glafs of any inflammable fpirit, coloured

. yellow or brown with oak, or with long remaining in the calk, will infrantly turn it of a bright and beautiful" blue. The beft way of judging in thefe cafes is by the nofe and palate. Dilute a quantity of brandy confiderably with water, and you will perceive the malt-tafte, if mixed with malt fpirits; or burn a little in a fpoon, and by the fmcll and tafte of the water it leaves, you will eafil'y judge whether there be malt in it. Shaw's Leftures, p. 1 25, 126. Proof fpirits may be diftinguifhed into three kinds, perfeB proof, more than perfeB proof, and Irfs than perfeB proof ". By perfeB proof is ufually underftood that crown of bubbles, before mentioned, of a certain fize, arifing as a head upon a fmall quantity of a well-qualified fpirit fhook in a (lender vial. Proof more than perfeB, is that in which the bubbles, raited

• by fhaking the fpirit, are larger than thofe on the common or perfea proof, and go off more fuddenly ; that is, ac- cording as the fpirit is higher, or approaches more to the nature of reflihed fpirit, or, as it is ufually called, fpirit of wine. J

Proof lefs than perfeB, is that wherein the bubbles are fmaller, and go off quicker and fainter than in ported proof; the fpirit, in this cafe, being mixed with more than its own quantity of phlegm, or is too poor for fale. In commerce, with regard to fpirits, it would certainly be a much better method to abolifh fuch uncertain proofs and to make all the goods of the ftrength of what we call fpirits of wine ; that is, a totally inflammable fpirit, whofe purity is much greater, whofe ftrength may always be found out with exaanefs, and whofe bulk, ftowage, carriao-e and encumbrance, would be only half, in reo-ard to that of brandy or proof fpirit; and it might at all tim°es, as occa- lion called for it, be mixed into a great variety of exem- poraneous liquors, and the exaft degree of ftrength would

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L e fn, ways pfedr generally unfatisfiiftnrv th^t ;, :.. _.. — c_ r ..

proves fo te-

tnat the common diftillers, till they have fallen into a'beUe manner of working, mould come into the propofal. But if; nftead or the common way of rectifying by the hot-ftill hey would try the ufing a large balneum maria-, made of a large rectangular boiler, and a fet of tall conical veflels, they will find that httle fire, and little attendance, and confe- qucntly very httle expence, will, in this manner, furnifh them with fpnts reduced at once to this ftahdard, and greatly fupenor, m all refpecte, to the common ones of the fame ftrength. In this cafe there would be no need of any addition of ialts ; but the diftiller may work more peifeflly, and more expeditioufly without them, and thus preferve the fine effential yinofity of the fpirit, which in the common way of working they conftantly lofe. The advantage of this method would be yet oreater to the apothecaries, and the makers of compound cardial waters, who want only a pure fpirit of fuch a ftrength, and fuffer greatly in the hnenefs and perflation of their commodities, by the fpirit they are obliged to ufe having in it a fulfome and naufeous oil of its own, which will always mix itfelf with their compofitions, and the oils of the aromatics, tic. which they add to it. If fpirits were brouabt to this Stand- ard for the market, there would be no poifibilitv of deceit, and no farther examination need be made of it by the buyer, than its burning perfeaiy dry in a fpoon. ShavSs Effay on Diftillery. Sec the anicle Strength. It ,s however to be obferved, that though the burning fpirits aWa L m A T" ma y fe "-e the trader in the common way, I" r! 1 y eoS '°Y has obferved that they are no proofs for the philofopher, or the chemift, being not at all determinate or exadt, though commonly fuppofed fo. From what has been" laid, it appears that brandy is much more inflammable than wine, and fpirit of wine much more lo than brandy, and ought to bum away without leaving any remainder. Hence it is vulgarly fuppofed, that fuch fpirit of wine as burns wholly away contains no phlegm, and that if two parcels of fpirit both burn wholly away in this manner, they muft be the fame in ftrength, and in all their qualities ; but Mr. Geoffroy has proved by experiment, that fuch fpirit as burns wholly away, does yet contain a great deal of water, and that two parcels both may bum thus away, and yet be very different ; and that this trial is not determined by the entire abfenceof the phlegm, but by its proportion to the oil.

If the fame fpirit of wine, which in the common way of burning leaves no water, be again tried, by burning it in a hollow veflcl fet to float in a large quantity of cold water, it will then leave a confiderable quantity of water ; nay, all that is reaped only in the common way leaves a We por- tion of phlegm on this experiment. The plain reafon of which is, that this is the only fair trial, the other in the common way being fallacious. In this there is no more water left than was in the fpirit ; but in thc other, the vefl'el becoming heated by the burning of the fpirit, that heat gra- dually evaporates the water, as the fpirit burns away; fo that the one is as foon gone as the other. But keeping the veffel cool by external water, prevents that evaporation, and confequently retains and difcovers all that cannot burn of the fpirit. ■

The quantity of water thus difcovered In fpirit of wine is very great, and it has always been found, that in propor- tion as the experiment has been made more and more per- fea, the fpirit has always appeared proportionably lefs and lefs fo.

The quality of the phlegm that is left, is alfo of ufe to judge of the fpirit by ; if that were perfeaiy fine; this ought to be perfeaiy limpid and clear, and without tafte or fmell : as it wants either of thefe properties, it is a proof of the want of perfeaion of the fpirit it is obtained from ; but the greateft of all its defeBs, is its having a coarfe oil fwim- ming upon it, and giving the colours of the rainbow in dif- ferent lights. Mem. Acad. Par. 1718. ReBified Spirit, or alcohol. A perfeaiy reBificd fpirit of wine, or fuch as is entirely freed from water, is a thing of frequent and neceffary ufe in the nice operations of che- miftry.

It had ufed to be prepared, either by often diftilling the fpirit, and every time drawing over only half of it, and repeating this till the half remaining in "the cucurbit ap- peared as ftrong as that drawn over ; or elfe by raifino- it to a great height from the body of the veffel, and thi" in a very gentle heat, fo that fpirit alone could rife, the water not being capable of being driven fo far by that deo-ree of beat.

But the accurate Boerhaave always found upon trial, that
 * there was ftill remaining fome water in thefe fpirits, whether

prepared by the firft or fecond procefs, or both. Boerhaave's Chem. Pait 2. p. 124.

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