396 intelligence and Miscellanies. 



31. Packfong. — This substance, as analysed by M. Brews- 

 ter, is composed of 31-6 parts of nickel, 25-4 of zinc, 40*4 of 

 copper, and 2'G of iron. It is employed in China in the fab- 

 rication of a great number of utensils such as vases, teapots, 

 goblets, (fc.c. It has the lustre, color and sound of silver. 



M. de Gersdorff, desiring to introduce into Europe so val- 

 uable an alloy, has established at Vienna, a manufactory, in 

 which he prepares this substance in large quantities. His 

 process is as follows : 



After breaking the nickel into pieces of the size of a small 

 nut, and dividing the copper and zinc, the three metals are 

 mixed, and put into a crucible, in such a manner that copper 

 may be both at bottom and top ; the whole is covered with 

 pulverized charcoal and the crucible is heated in a wind fur- 

 nace. It is necessary frequently to stir the mass, in order 

 that the nickel, which is difficult to fuse, may combine with 

 the other metals and the alloy be homogeneous ; it must also 

 be kept a long time in fusion, even at the risk of separating a 

 small portion of the zinc by volatilisation. 



The relative proportion of the three metals which com- 

 pose the packfong, should vary according to the use which 

 is to be made of it. That destined for the fabrication of 

 spoons, forks, &c, ought to contain 0.25 nickel, 0.25 zinc, 

 0.50 copper. When it is to be used in ornamenting knives, 

 snuffers, &c. it should contain 22 nickel, 23 zinc, and 55 

 copper. The packfong most suitable for plating, consists of 

 20 nickel, 20 zinc and 55 copper. For objects which are to 

 be soldered, as candlesticks, spurs, &c. the best alloy is 20 

 nickel, 20 zinc, 57 copper and 3 lead. 



The addition of .020 to .025 of iron or steel, renders 

 packfong much more white, but at the same time more brit- 

 tle. It is necessary that the iron should be previously melt- 

 ed with the copper. 



Packfong cannot be rolled without the greatest precau- 

 tion. Every time it is passed through the rollers, it must be 

 heated to a cherry red and slowly cooled. When the sheets 

 present any rent, it must be hammered out before it passes 

 again through the rollers. 



Tlie goldsmiths apply the pumice stone to packfong, as to 

 silver. Color is given to it, by dipping it in a mixture of 100 

 parts water and 14 sulphuric acid. 



When the turning and filings of packfong are remelted, it 

 is best to add .03 to .04 of zinc to replace that which has been 

 volatilised. 



