From these experiments, which I made with as much precision as possible, we may conclude, first, that the time of refrigeration of iron, so as to be held in the hand, is to that of copper : : 531/2 : 45, and so to the point of temperature : : 142 : 125.

2dly, That the time of refrigeration of iron, so as to be held in the hand, is to that of the first refrigeration of common marble : : 531/2 : 351/2 and their entire refrigeration : : 142 : 110.

3dly, that the time of refrigeration of iron, to that of gres, so as to be held in the hand, is : : 531/2 : 32 and : : 142 : 1021/2, for their entire refrigeration.

4thly, That the time of refrigeration of iron to that of lead, so as to be held in the hand, is : : 531/2 : 27 and 142 : 941/2 for their entire refrigeration.

In an oven hot enough to melt tin, although all the coals and cinders were drawn out, I placed, on a piece of iron wire, five bullets, distant from one another about nine lines, after which the oven was shut, and having drawn them out, in about 18 minutes they cooled,

So as to be held in the hand
for half a second.		To actual
temperature.
Melted tin in8In24
Silver in14In40
Gold in15In46
Copper in161/2In50
Iron in18In56

In the same oven, but with a slower heat, the same bullets with an other bullet of tin, cooled,

So as to be held in the hand
for half a second.		To actual
temperature.
Tin in7In20
Silver in11In56
Gold in121/2In40
Copper in14In43
Iron in161/2In47