hms of mercury. In a short time the silver will be precipitated ta the most beautiful arborescent form, resembling real vegetation. This has been generally termed the Arbor Uianse.  Metallic watering, or for blanc moi^e. This article, of Parisian invention, which is much employed to cover ornamental cabinet work, dressing boxes, telescopes, opera glasses, Stc . &c. is propared in the following manner.  Sulphuric acid is to be diluted with from seven to nine parts of water; then dip a sponge or rag into it, and wash ith it tbe surface of a sheet c4 nn This will speedily exhibit an appearance of crystalhzation, whicn is the moir£.  This effect, however, cannot be easily produced Dpon every sort of sheet tin, for if the sheet has been much hardened by hammering or rolling, then the moire cannot be effected until the sheet has been heated so as to produce an incipient fusion on the surface, after which the acid will act upon it, anhttp://www.cheap-beatsbydressale.com/ .d produce the moire1. Almost any acid will do as well as the sulphuric, and it is said that the citric acid dissolved in a sufficient quantity of water, answers better than any other.  The moire may be much improved by employnig the blow pipe, to f-irm small and beautiful specks on the surface of the tin, previous to the application, of the acid.  When the moirf; has been formed, the plate isCheap Beats By Dr Dre Id be varnished and polished, the varnish being tinted with any glazing colour, and thus the red, green, yellow, and pearl coloured moires are manufactured.  Chinese sheet lead. The operation is carried on by two men; one is seated on the floor with a large flat stone before hiCheap Beats By Dre m, and with a moveable flat stone-stand at his side. Cheap Dre Beats Headphones A second quantity of lead is poured in a similar manner, and a similar plate formed, the process being carried an with singular rapidity. The rough edges of the plates are then cut off, and they are soldered together for use.  Mr Wad del has applied this method with great success to the formation of thin plates of zinc, for pal van ic purposes.  PARTING.  By this process gold and silver are separated from each other. These two metals equally resisting the action of fire and lead, must therefore be separated by other means. This is effected by different menstrua. Nitrous acid, marine acid, and sulphur, which cannot attack gold, operate upon silver; and these are the principal agents employed m this process.  Parting by nitrous acid is most convenient, consequently most used,—indeed, it is the only one employed by goldsmiths. This is called simply parting.  That made by the marine acid is by cementation, ind is called centra ted parting; and parting by sulphur is made by fusion, and called Dkt Fartnro.  Parting by aquafortis. This process cannot succeed"unless we attend to some essential circumstances: 1st. the gold and silver must be in a proper portion, viz. the silver ought to be three parts to one of gold ; though a nass containing two parts of silver to one of gold may be parted. To judge of the quality ot the metal to be parted, assayers make a comparison upon a touch-stone, between it aDiscount Beats By Dre nd certain needles composed of gold and silver, in graduated proportions, and properly marked; which are called Proof Needtes. If this triat shews that the silver is not to the gold as three to one, the mass is improper for the operation, unless more silver be tdded; and 2dly, that the parting may be exact, the aqua fortis must be very pure, especially free trom anv mixture of the vitriolic or marine acid. For if tins were not attended to, t juantity of sil  ver propot tionnhle to these two foreign acids would be separated during the solution; and this quantity of sulphate of silver would remain mit-gled with the gold,