A system of chemistry : comprehending the history, theory, and practice of the science, according to the latest discoveries and improvements ; illustrated with copper plates.

Date:
MDCCXCI [1791]
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Licence: Public Domain Mark

Credit: A system of chemistry : comprehending the history, theory, and practice of the science, according to the latest discoveries and improvements ; illustrated with copper plates. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    ti6 i - ■ 8n Bympithe- tii ink. CHEMISTRY. Practice. »*3 Oil of arfc fcic. 8i4 Mamie .1 of the former experiment he found 30 gmns of tance, chiefly 1 combinatioa «r ealcare. .rth with muriatic acid. en the mercuries vit.c precipitates, the union be- tween the marine acid and regal us is totally diflbked ; icr, by frequent warnings, becomes pcr- frce from every particle of acid, which unites with the water made aie or, and is then called very . o/bphk /'pint of vitriol. XIV. With Regulm »} Cobalt. Pure fpirit of fait dif- (emimctal-into a reddifh yellow liquor, which immediate1) becomes green from a very gentle warmth. On faturating the folution with urinous lpirits, the precipitate appears at fifft white, but afterwards be- comes blue, and ai length yellow. If the nitrous acid is added to folutions of regtilus of cobalr, they alfume 9 deep emerald green when moderately heated, and on cooling become red as at firft. Duly evaporated, they yield rofe-colourcd cryftals, which change their colour by heat in the fame manner. This folution makes a curious fympathetic ink, the invention of which is commonly nfcribed to M. Hellot, though he himfelf acknowledges that he received the fir ft hint of it from a German chemift in 1736. Any thing wrote with this folution is invilible when dry and cold ; but af- fnmes a fine green colour when warm, and will again difappear on being cooled ; but if the heat has been too violent, the writing (till appears. M. Hellot ob- ferves, that if nitre or borax be added to the nitrous folution, the characters wrote with it become rofe- colourcd when heated , and if fea-falt is afterwards pallid over them, they become Hue ; that with alkali fuificicnt to faturate the acid, they change purple and red witli heat.—A blue fympathetic ink may be made from cobalt in the following manner. Take of an earthy ore of cobalt, as free from iron as poffible, one ounce. Bruife it, but not to too fine a powder. Then put it into a cylindrical glafs, with 16 ounces of diftil- led vinegar, and fet the mixture in hot (and for the fpace of fix days, ftirring it frequently ; or clfe boil it directly till there remain but four ounces. Filter and evaporate it to one half. If your folution be of a rofe colour, you may be certain that your cobalt is of the right fort. A red brown colour is a fign of the folu- tion containing iron; in which cafe the procefs fails. To two ounces of the folution thus reduced, add two drachms of common falt.-*~Set the whole in a warm place to didblve, and the ink is made. XV. With Regulus of Arfeme. This fubftance is foluble in all acids ; but the nature of the compounds formed by fuch an union is little known. If half a pound of regulus is diftilled with one pound of corro- five fublimate, a thin fmoking liquor and a butyrace- ous fubftance will be obtained, as in making the fmo- king liquor of Libavius. By repeated rectifications, this butter may be almoft all converted into fpirit. If equal parts of the arfenic and fublimate are ufed, a pon- derous black oil comes over along with the fpirit, which cannot be mixed with it. By rectification in a clean retort they will become cleafe-, but ftill will not incor- porate. If they are now returned upon the red mafs remaining in the firft retort, and again diftilled, a much more ponderous oil than the former will be ob- tained. XVI. Wit 8 Infatnmabl; Suijlanccs. The acid of fea- falt is very little difpofed to contract any union with Marine the p while in a liquid ft ue ; and much lefs acul ft, even in its moll concentrated ftate, than cither the ,tI conibl vitriolic or nitrons. Mr Beaume, however, has found, ' ' - that a (mall quantity 01 eilicr, fimilar to that prepared with the vitriolic and nitrous acids, may be obtained by cauling the fumes pf the marine acid unite with thofe of fpiiit of wine. Others, and particularly fome German Chemifts, attempted to make this liquor, by employing a marine acid previoully combined with me- tallic fubftances, fuch- as butter of antimony. The fmoking liquor of. Libavius fucceeds belt. If equal parts of this liquor and highly rectified fpirit of wine are diftilled together, a considerable quantity of true ether is produced ; but which, like the vitrio- lic and nitrous ether, muft be rectified in order to its greater purity. The tin contained in the fmoking li- quor is leparated and precipitated in white powder. In this procefs, the acid is probably more difpofed to unite with the fpirit of wine, by having already be- gun to combine with the inflammable principle of the metal.—For marine ether, Mr Dollfufs recommends to put into a retort four ounces of digeftive fait previouf- ly well dried and powdered, and two ounces of man- ganefe ; pouring upon this a mixture of five ounces of fpirit o{ wine and two of oil of vitriol ; the firft five ounces and a half of the diftilled liquor being poured back on the refiduum, and the whole afterwards drawn off by a gentle heat. The fpirit of fait thus obtained had a very penetrating agreeable odour, fomewhat like that of nitrous ether ; and at firft fwam upon the top of water ; but at length mixed with it on being agi- tated for a long time. Towards the end of the diftil- lation a little oil was obtained, which did not mix with the water; and by the addition of four ounces more of fpirit of w ine, moTe of the dulcified acid was obtained. With regard to this kind of ether, however, Mr Weftrumb denies that it can be made by any me- thod hitherto known ; and infifts, that all the liquids as yet produced under the name of marine ether are in reality dulcified fpirit of fait, and not true ether, which will fvvim on the top of water. g2, Dr Prieftley has obferved, that the pure marine acid, Attradioa when reduced to an invilible aerial ftate, has a ftrong forphlogif- affinity with phlogifton; fo that it decompofes many ton« fubftances that contain it, and forms with them an air permanently inflammable. By giving it more time, it will extract phlogifton from dry wood, crufts of bread not burnt, dryflefh; and, what is ftill more extraordi- nary, from flints. From what has been above related, it appears that the dephlogifticated fpirit of fait has a very ftrong attraction for phlogifton. EUential oil of mint abforbed the marine acid air pretty faft, and prefently became of a deep brown co- lour. When taken out of this air, it was of the con- fiftenceof treacle, and funk in water, fmelling different- ly from what it did before ; but ftill the fmell of the mint was predominant. Oil of turpentine was alfo much thickened ; and became of a deep brown colour, by being faturated with acid air. Ether abforbed the air very faft ; and became firft of a turbid white, and then of a yellow and brown colour. In one night a conf.derable quantity of ftrongly inflammable air was produced. Having once faturated a quantity of ether with acid air,