110 Some Particulars respecting the 
able degree of heat for the skin of the experimenter ; but it 
is too high, as we shall see. 
There is no contact between the hand and the metal ; this 
is a fact which appears to me positively established. If there 
be no contact, heating can take place only by radiation ; and 
that is enormous, it must be admitted. But if the radiation 
be neutralised by reflection, and such is the case, it is the 
same as if it did not exist; and, in short, it is in these nor- 
mal conditions, so to speak, that the operator is placed. 
I think that I have long since proved that water, in a 
spheroidal state, has the singular property of reflecting ra- 
diated caloric,* and that its temperature never reaches that 
of ebullition ; heitce it follows that the finger, when moist, 
cannot be raised to the temperature of + 100° C., the experi- 
ments not being continued sufficiently long to allow the hu- 
midity entirely to evaporate. 
To state the case briefly: On passing the hand through 
melted metal, it is insulated, the moisture which covers it 
passes into the spheroidal state, reflects the radiated caloric, 
and does not become heated to the boiling point ; that is the 
whole. 
I was, therefore, justified in saying, at the outset, that this 
experiment, dangerous in appearance, is almost insignificant 
in reality. 
I have repeated it often with lead, bronze, &c., and always 
with the same success. + 
Such individuals as remember the experiment which con- 
sists of plunging a mass of silver or incandescent platina in 
water, will easily conceive the mechanism of the latter. In 
the first, the water recedes from the metal, which then seems 
* A new Branch of Physics, or Studies on Bodies in a Spheroidal State, p. 24, 
&e., 132, &e. See also my two Letters to the Academy of Sciences, dated the 
14th and 21stof July 1845. An explanation of this phenomenon will be found 
in the places referred to. 
+ The experiments on melted metal were made in M. Davidson’s foundry, 
at Villette, and on bronze in that of M. Nerat, Pierre-Levée Street. I am 
happy to have the opportunity of publicly thanking these gentlemen for their 
kind assistance. 
