B™ 



VI. METALS.-CoppKH. 231 



SILVER. 



Refin'ed silver, Argcntum cupcllatum. Silver cupelled with 

 a sufficient quantity of lead to scorify the copper mixed with it. 

 Used to make preparations of silver. 



Pure silver. Dissolve refined silver in nitric acid, add a 

 solution of salt as long as any sediment falls ; boil the sediment 

 while still moist, along with water in a bright iron vessel ; wash 

 and dry the silver. Kquiv. 13 5. 



Silver leaf, Argentum foliatiim. Used to cover pills and 

 other substances. 



Shell silver, Argentum in miisndis. Grind the cuttings of 

 silver leaf with strong gum water, and spread it in muscle shells. 

 Used for writing silver-coloured letters, but tarnishes, and is 

 inferior to argentum musivum, unless varnished over. 



Silver dust. Crocus orgenti. Add slips of copper to a solu- 

 tion of silver in spirit of nitre, and wash the precipitated metal 

 with spirit of wine : used in japanning. 



aUICKSILVER. 



Quicksilver, Quik, Mercury^ Argentum vivum, Mercurius, 

 Hydrargyrus, Hydrargyrum. Found native, but mostly extracted 

 from the native sulphurets. Given in obstinate costivcness to the 

 ( \tcnt of Ibj or Ibjss, in hopes of forcing a passage by its weight. 

 I'-ed by water-gilders to dissolve their gold, by looking-glass 

 akers to soften their tinfoil, by barometer and thermometer 

 akcrs for their instruments, and in some other arts. Imported 

 from Idria through Holland and Italy; from Spain, Nepaul, and 

 Japan. 



Purified quicksilver, Argentum vivum purificatum, Hy- 

 drargyrm purificatus, Hydrargyrum piirijicatum. Distil it from 

 an iron vessel. The imported quik is so pure, and any adultera- 

 tion, if attempted, so readily discoverable by workmen accus- 

 tomed to handle it, that this operation is superfluous. 



2. Strain the quik that has been used by looking-glass makers 

 through chamois leather. Used by apothecaries, when it can be 

 got cheap, to make blue pill and mercurial ointment. 



.3. Distil Dutch vermilion and iron {\\'\\vjr<, of each Jib. into 

 water ; equiv. 25. 



COl'I'EU. 



Sheet covvv.h. Cuprum, This, like pewter, is used for making 

 many phafmaceutical vessels, which arc generally tinned on the 

 Miside : these vessels have been proscribed by the colleges upon 

 msufficient grounds, since, like lead, it cannot be dissolved while 



