Volume 1

A general dictionary of arts and sciences: or a complete system of literature ... Poetry ... and theology / by ... James Scott ... The mathematical branches by Mr. Charles Green ... Naval and marine affairs ... by Mr. William Falconer ... Botany and gardening, by Mr. James Meader ... And the other branches of literature, by a society of gentlemen.

Date:: 1765-1766

Credit: A general dictionary of arts and sciences: or a complete system of literature ... Poetry ... and theology / by ... James Scott ... The mathematical branches by Mr. Charles Green ... Naval and marine affairs ... by Mr. William Falconer ... Botany and gardening, by Mr. James Meader ... And the other branches of literature, by a society of gentlemen. Source: Wellcome Collection.

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$ANCA prefently appears, efpecially when the wine begins to grow finer, and more fubtile. Is there the leaft indication of an acid in ripe mealy corn? and yet even this, after a little fermentation, difcovers an acidity. As thefe acids are fomething different, they are generally called vinous acids. “They are of two forts ; for they are either difperfed through the wine, in form of liquid acids, or elfe gra- dually collect themfelves together in the wine, and fix themfelves to the furface of the veflel, in the folid form of tartar. ahs - But the acids of ‘vegetables produced by a fecond fermentation arg generally called acetofe : for if any known wines are, by an admixture of auftere, acetofe fermentation, they will be converted into vinegars, will confume their own tartar, become much more acid, and acquire a fironger and more durable fournefs, which will remain even in di- ftillation : hence there may be obtained from vi- negars, by diftillation, a pure active acid of the utmoft fervice in chemiftry, ‘ Tt will alfo be neceflary to take notice here of what are called fermenting acids; by which we mean vegetable juices in the very act of fermenta- tion, and confequently in a kind of middle ftate between that.which is natural to them, and-that which they obtain when the fermentation is com- pleated; for, during this interval, the moft elaftic part of the fermenting vere acquires fuch a power as is hardly to be equalled by any thing in nature : for if this favage, incoercible, explofive, acid {pi- rit, rifing from a vaft quantity of fermentiig vege- tables, fhould pafs through a very fmall vent-hole into the noftrils of the ftrongeft man, it would ftrike him dead in an inftant. If it does not, act with all its force, it caufes a fudden apoplexy ;. if Jefs powerful, ftill, a lofs of the fenfes, with a pa- raplegia ; if very lightly, only a vertigo. © The truth of this has been too, certainly proved by many melancholy inftances. _ There are alfo difcovered other very fingular oily nature; we mean fuch as are drawn. from vege- tables by fire in a clofe veffel. Thus the wood of guaiacum, juniper, oak, and a great many others, if reduced to dry fhavings, and carefully diftilled in a retort, will yield a limpid reddifh liquor, which is very acid, fomewhat oily, and has a good, deal of the {mell of a herring dried.in the f{moke. This liquid may be rendered ftronger by depuration. and rectification ; and then the folvent virtue of this menftruum will appear to be very fingular. . Foffile native acids are rarely to be met with ; for itis now difcovered, that the medicinal waters, once confidered as an acid, approach, in every character, nearer to an alcali. There is eften indeed a vapour obfetved in mines, which re- marks demonftrates its acidity; but it is very fel- But whenever it happens, which is very often fixed and palpable: and when it is afterwards. it is pofible for us to judge, appears to be always. ' For if it lays hold of a pinguious foffile, it pro-: duces various kinds of fulphurs, which, when: erated, and mixed with the humid air, yield the Pit or oi] of fulphur per campanum.. If you pour this acid liquor into a clean glafs veffel, and expofe it for a confiderable time to a heat equal to that of boiling water, you will diftil from it a confiderable quantity of pure water, which, whilft the fulphur was burning, had infinuated itfelf out of the air into the acid fumes of the fulphur; and there will then remain at the bottom a ponderous, thick, the pureft oil of vitriol, except in its having no par- more or lefs in oil of vitriol. _ . . But if ‘this acid happens to corrode lime-ftones,. it then producesalums, which.are different accord— ing to the diverfity of the matter which is mixed, calcined, and then with an intenfe fire urged into. quor, which, when| purified according to art, is , Again, ,if native green vitriol be reduced, by the and then expofed to a fire gradually increafed to the, fore obtained from fulphur and alum. ‘The blue vitriol likewife treated in the fame: manner, yields a:liquid,. which is the fame with the former ; nor can it be diftinguifhed from them,, if rectified according to art, Another foffile acid which we are acquainted, with, is produced from nitre only, fo that there ne- ~ ver was perhaps a fingle drop feen of it in the world. but what was ditilled from nitre. For if nitre be intimately mixed with three times its quantity of nature, and then urged with a very ftrong fire, a. great part of it will be converted into red fumes, which, being condenfed intoa liquid, is called fpirit: of nitre. Or if dry nitre be mixed with an equal: quantity of oil of vitriol, and diitilled in the ftrong-. Oke$

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