C.375 ) 
V. Ox the different Proportions of the Metals employed in the. 
- Preparation of /oft Solder. ; 
\ V HEN lead, tin, and bifmuth are mixed in a cer- 
tain proportion, they produce a metal exceedingly fufible, 
which is known by the name of foft folder; but which, 
from its fingular properties, may be applied with advantage 
to many other ufeful purpofes. Newton, and after him 
Kraft and Muffchenbroek, obferved, that, 5 parts of bif- 
muth, 3 of tin and 2 of lead, alfo 5 parts of bifmuth, 4 of 
tin and 1 part of lead, melted with a heat of 220 degrees 
of Fahrenheit, and they found that various mixtures of 
this kind were fufible by a heat not much greater than that 
of boiling water. At a later period V. Rofe, a German na- 
turalift, difcovered that a mixture of. 4 parts of bifmuth, 2 
of tin and 2 of lead, as Kunkel recommended for foldering 
tin; and d’Arcet among the French, that a mixture of 8 
parts of bifmuth, 3 of tin and 5 of lead; or 8 of bifmuth, 
4 of tin and 4 of lead; or 8 of bifmuth, 2 of tin and 6 of 
lead; alfo 16 of bifmuth, 7 of tin and g of lead, all melted, 
or at leaft became foft, in boiling water. " 
According to the experiments made by Profeffor Gmelin, 
“refpecting the fufion.of thefe three metals, a mixture, fuch 
as that before recommended by Homberg to anatomifts for 
injecting into the veffels of their preparations, confifting of 
2 parts of bifmuth, 1 part of tin and 1 of lead, which is the 
fame as Rofe propofed, gave a metal that was fufed in boil- 
ing water. A mixture of 6 or more parts of bifmuth, 6 of 
fin and 3 of Jeads-or 1 part of bifmuth, 2 parts of tin and. 
2 of-lead, gave, according to Klein, the folder ufed by the 
-tin-button-makers. The fame workmen ufe alfo for folder. 
ing, according to Klein, a mixture of 4 parts of bifmuth, 
3 parts of tin and 5 parts of lead. Among the many foft 
folders employed by the tin-men, a mixture of one part of 
bifmuth, 2 parts of tin, and 1 part of lead, is, according to 
Bba Klein, 
