5o 
TlMEHRI. 
separation is to be ascertained by means of a pocket 
balance which is described in the report, and which 
seems to be simple and not liable to get out of order, 
and is said to weigh the toVo part of a grain. 
The fineness of the gold resulting from the operations 
above described, is ascertained by the use of touch-stone 
needles made in the manner following: — 
Copper wire is drawn through a wire plate with square holes to about 
the size of the square point of a ten-penny nail and then cut into five 
lengths of two inches each. Ten grains of pure gold are melted before 
the blow-pipe on charcoal, hammered square, and soldered to the end of 
one of the copper wires. The gold is then filed down even with the 
sides of the wire which is stamped iooo representing pure gold. For 
the other end, an alloy of nine grains pure gold and one of pure 
silver is carefully made on charcoal, hammered square, soldered on to 
the other end of the needle and is stamped goo. The other four needles 
are made in the same way. 
Grains Gold. Grains Silver. 
8 ... ... 2 
7 ... ... 3 
6 ... ... 4 
5 .- :•• S 
6 
7 
Stamped. 
8oo 
700 
600 
500 
400 
300 
200 
100 
The second set is made in exaftly the same way, except 
that copper is substituted for silver in the alloy. 
Care must be taken not to make the solder so hot 
that the alloy is melted and a new and unknown alloy 
made by fusing with it ; and the alloy should be much 
larger than the needle, so that it can be filed down and 
the solder removed from all parts except where the 
copper is joined to it. 
The true touch-stone is a black quartz called basanite, 
found in Bohemia, Saxony and Silesia, and is best 
