supports the muffle. c, c are the flues through which the flame escapes; n is a pipe or tube on the top of the muffle to allow vapours to escape; r, r, tubes in the door of the muffle, through which the proof pieces are passed. In the interior of the muffle, small brackets or projec tions i, i are placed, which support bars of iron encased in porcelain, on which the plates of glass which are to be burned rest. Dry pulverized lime is sometimes laid on the bottom of the muffle and the glass rested on the lime. Several layers of glass may be placed in the muffle together, with layers of lime between them. This is the better arrangement. As the paintings retain considerable oil, it is necessary, when the muffle is first charged, to heat gently, in order to volatilize or decompose this oil, leaving the muffle open. When the oil is driven off, the muffle is closed, and the fire increased. A greater or less intensity of heat is directed from one part to another of the muffle, by opening or closing the flues c, so as to cause the flames to pass over any point desired. The temperature suitable for burning is judged of by placing in the muffle pieces of glass painted with a little carmine. The heat should not be carried beyond the point at which the carmine is well developed. These pieces. are fastened to iron wires, by which they may be passed in or out of the muffle through the tubes r, r. In this way the progress of the burning may be closely watched. When the carmine is well developed, the fire should be arrested, and the muffle allowed to cool. When the muffle has entirely cooled, the glass is withdrawn. If

any parts are defective, they may be retouched and put in the muffle a second time. Sufficient time should be allowed for the glass to become entirely cool, before withdrawing it.

HARMONY OF COLOURS.

EVERY one must have observed that certain colours, when brought together, mutually set each other off tc advantage, while others have altogether a different effect. This must be carefully attended to by every painter who would study beauty or elegance in the appearance of his work.

Whites will set off well with any colour whatever. Reds set off best with whites, blacks, or yellows. Blues with whites or yellows.

Greens with blacks and whites.

Gold sets off well either with blacks or browns.

In lettering or edging with gold, a white ground has a delicate appearance for a time, but it soon becomes dingy. The best grounds for gold are Saxon blue, ver milion, and lake.

MISCELLANEOUS SUBJECTS

AND

USEFUL RECEIPTS.

THOUGH the whole of the following subjects and receipts cannot be strictly said to relate to the trades of the Painter, Gilder, or Varnisher, yet most of them are so intimately connected with them, and also so useful to him, that the present Manual could not be considered complete without their being introduced.

To increase the Strength of common Rectified Spirits of Wine, so as to make it equal to that of the best.

Take a pint of the common spirits, and put it into a bottle which it will only fill about three-quarters full. Add to it half an ounce of pearlash or salt of tartar, powdered as much as it can be without occasioning any great loss of its heat. Shake the mixture frequently for about half an hour, before which time a considerable sediment, like phlegm, will be separated from the spirits, and will appear along with the undissolved pearlash or

salt at the bottom of the bottle. Then pour the spirit off into another bottle, being careful to bring none of the sediment or salt along with it.* To the quantity just poured off add half an ounce of pearlash, powdered and heated as before, and repeat the same treatment. Continue to do this as often as you find necessary till you perceive little or no sediment: when this is the case, an ounce of alum, powdered and made hot, but not burned, must be put into the spirits, and suffered to remain some hours, the bottle being frequently shaken during the time; after which the spirit, when poured off, will be found free from all impurities, and equal to the best rectified spirits of wine.

To Silver by Heat.

Dissolve an ounce of pure silver in aqua fortis, and precipitate it with common salt; to which add half a pound of sal-ammoniac, sandever, and white vitriol, and a quarter of an ounce of sublimate.

Or dissolve an ounce of pure silver in aqua fortis, and precipitate it with common salt; and add, after washing, six ounces of common salt, three ounces each of sandever and white vitriol, and a quarter of an ounce of sublimate. These are to be ground into a paste, upon a fine stone, with a muller; the substance to be silvered must be rubbed over with a sufficient quantity of the paste, and

* For this purpose, you had better use what is called a separat* ng funnel, if you can procure it.