+92] CH A by plunging it in a solution of the in er of sulphur, towhi-'h it imparts a green colour. Melted with co- I :ss frits, or glasses, it gives a pale, dark yellow, reddish, brown- i c h, or blackish colour, accordingly as the inflammable matter is in greater or less proportion. Fresh charcoal made of wood strongly at- tracts the air, and will absorb it for a considerable time 5 but Dr. Priestley uniformly observed, that, after submitting it to distilla- tion, the expelled air was less pure than that or t:,e atmosphere, and part of it was fixed air. Hence it may occasionally be employed in a dry and powdered state, for d and foul habitations. Lastly, Dr. Priestley has discovered that several of the metals, such as cop- per, iron, silver, &c. may be con- verted into charcoal, by passing the steam of either spirit of wine or turpentine, over them when red hot: and this, by way of di-tineV n, he calls the charcoal of metals. As charcoal has been separated from the purest spirit of wine in the pro- 3 of making aether, M. Lavoi- sier is of opinion, that it is one of the constituent parts, or elements, of that volatile liquid. Uses. Besides the great advan- tage which charcoal affords to the artist and manufacturer, it has lately been employed with consi- derable success. 1. In correcting the burnt or emnyreumatic taste of ardent spirits ; 2. In depriving rancid oil of its disagreeable fla- vour ; and 3. In restoring putrid meat. For these useful purposes, however, it is fit only when kept in close vessels, anaaedaately aft r it has been prepared, so that it may b no acidity, or fixed air, from the common atmosphere. When employed in the two nrot-mention- CH A ed cases, it should be - reduced to powder, a very large
- tired for
the rectincaf.or: tor* but a smaller prop* irtian, for puri- fying animal or vegetable oil, so that even the common tra'n-o:. be rendered fir for being burnt in ies of this descrL.tiori have lately been established in the vici- nity of London, of which we shall only mention that carried on by Mr-. Joshua Collier, of South- walk . From the great attracMon which charcoal possesses for any kind of oily matter, or for that invisible something, former!}- called / .', it is excellently adapt become an ext; in various branches of the arts, We shall therefore communicate, the following abstract; of the late discoveries made on this subject, ch'efly by Prof. Lowitz, of St. Petersburgh. This philosopher found, that charcoal rendered the crystals of tartar very white and pure, when employed in preparing them ; that the marine and nitrous acids are decomposed by being dis- tilled upon it : that the red juices of v( u s are deprived of their coi< .v without losing part of their acidity ; that brown, rancid oils are rendered sweet and clear, by agitating them for some days with charcoal in powder; that it changes die smell of putrid vege- tables to that of a pure volatile alkali, and produces the same elfe6t on fresh meat. By boiling coals in powder, with honey, the pure sac- ine parts of the latter are said to be separated, and the honey to become a well-tasted sugar. Vine- gar concentrated by freezing, and distilled from a large portion of powdered
