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folution is wanted. The fame materials will fuc-ceed without the verdigris, if made in a copperveflel expofed to the air. Both thefe folutionsform the Aqua Sapphirina in pharmacy, ufedfometimes as an external application in fomefurgical cafes. Another method of producingammoniated copper immediately, is to fuper-faturate with ammonia any of the falts of cop-per. Thus the firft portion of this alkali addedto muriated copper (for example) which is of alight green, feparates a green oxyd of copper;more of the alkali rediflolves the oxyd, and theliquor now fhews the fine blue, which indicatesan ammoniated folution. In this way ammoniabecomes a very excellent tell for the prefenceof copper, diftinguilhing it by the colour andthe clear folution from every other metal exceptnickel.

Carbonat of ammonia will anfwer the famepurpol'e as pure ammonia in the above pro-celfes, the carbonic acid being moftly expelledduring the mutual aftion. This however is notnecefl'ary, l'mce carbonat of ammonia, as fuch,will alfo difl’olve oxyd of copper and retain it ina folid Hate. A fimple mixture, by trituration,of one part of folid fulphat of copper and threeparts of dry carbonat of ammonia effervefcesftrongly, and when carefully dried, forms amixed blue fait, the cuprum ammoniatum ofpharmacy.

A Angular circumftance takes place with am-moniated copper. If a bottle be filled full ofliquid ammonia with a few clean copper filings,and kept clofely corked, no folution enfues. aIf the bottle be now opened for a while andthen {hut, part of the copper is difl'olved, buttire liquor is Hill colourlefs, till on again un-corking the phial, when it fuddenly becomesblue at the top, and this colour fpreads ftowlydown to the bottom. A frefli addition of copperfilings, and again clofing the veffel, caufes theblue colour again to vanifh, but this is reftoredby the accefs of air. To explain this fa£I anobfervation made by Prouft may be added,which is, that the white muriated fub-oxyd ofcopper (formed by the folution of tin and alreadydefcribed) when fuperfaturated by-ammonia ina clofe vefTel, is indeed decompofed by it, andan ammoniated folution is formed, but colour-lefs, till expofed to the aftion of air, when itbecomes blue. It appears probable thereforethat copper requires to be only flightly oxy-genated to diflolve in ammonia, but in this (lateis colourlefs, and has a ftrong attraction for thatadditional dofe of oxygen which is necefl'ary to* Gren. k An, Chim. tom 38

give the beautiful blue by which the commonammoniated folution is diftinguifhed. In theexperiment above mentioned it is alfo probablethat the copper filings added to the blue folutionpartly difoxygenate and deprive it of colour, andthemfelves are thereby in part difl'olved, unlefsthe alkali be faturated.

Copper is in time oxydated and partially dif-folved by almoft every faline fubftance, eventhofe that are perfectly neutralized, fuch ascommon fait. This is proved by the fact thatall copper veflels long in contact with any falinematter and expofed to air, become graduallycovered with a green cruft of oxyd. This isalfo obfervable in copper-bottomed {hips, fromwhich, when the old {heathing is ripped off, avery large portion clijps off 1 in half-corrodedfcales. The decompofition by muriated am-monia is very rapid, and a green muriated oxydremains, which is faid to be the bafis of theBrunfwick Green.

When muriated ammonia and copper, orbetter, its oxyd, mixed dry are heated in a clofevefl'el, the muriat, in fubliming, carries up withit a portion of the metal (as it does with many,if not moft other metals) and greenifh-yellowflowers are collefted, which confift of muriatedammonia, with a finall and varying portion ofoxyd of copper, generally about eV- A part ofthe muriat is at the fame time decompofed andammoniacal gas is given out. -

Copper and fulphur readily unite. Whenequal parts of copper filings and flowers of ful-phur are mixed and heated in a crucible muchof the fulphur burns oft', but the remainder meltsinto a deep bluifti-black mafs, which is an arti-ficial fulphuret of copper. According to Prouft’*100 parts of copper take up in this way 28 offulphur, fo that the fulphuret is compofed ofabout 79 of metallic copper and 21 of fulphur.This combination contains no oxygen, and istherefore a fimple fulphuret of copper, and not afulphuretted oxyd. It is more fufible than copper,readily melting at a red-heat. By roafting inthe open air, the fulphur is expelled, and thenan oxyd of copper remains, (as with the nativefulphurets) but the la ft portions of fulphuradhere with great obftinacy. Dr. 1 hompfon calfo has found fulphur and copper filings tounite by merely being mixed together in thecold, with or without water, and remaininglong expofed to the air.

Hydro-fulphuretted water, or any of theliquid hydro-fulphurets added to the folutionsof copper produces a deep blueiflt-black pre-. p. 1 •jz, ‘ Elem, of Chemiftry,