REMARKS ON WOOD AND METAL. 
6$ 
ARTICLE IV. 
REMARKS ON WOOD AND METAL 
AS CONDUCTORS OF 
HEAT. 
BY EPHEB1COS IIORTICI'LTOR. 
In reading a late number of your Register I observed a reply to my 
remarks upon Mr. Cur’s criticism of Mr. Me’ Murtries communica¬ 
tion on Metallic Hothouses. Had I considered this reply as in the 
least establishing the truth of his assertions, or in any manner obv ia¬ 
ting the objections brought forward, as tending to point out the t.il- 
lacv of his deductions, I should not have troubled you with an an¬ 
swer. As he has not done so, but in fact promulgated more enor, I 
consider mvself, both for the sake of truth, and in case my silence 
might be understood as a virtual assent bound to make a reply ; leav¬ 
ing it entirely to vour own discretion, whether or not you may deem 
it worthy of insertion. 
Mr. Cur assumes that I misunderstood him, and explains thus: 
“ What I meant was, that wood and metal are equal conductors ot 
the heat of the sun or of our atmosphere, and not ol water and sand, 
&c,” This unquestionably is a most singular explanation, and with 
every reason deserves the epithet ot “ mere nonsense. I leat is a 
body which pervades all space; there is not a substance in creation 
which has been subjected to the scrutiny of investigation, in which 
heat has not been found in a combined state. In a simple or un- 
combined state it has never been detected, and on this account we 
know nothing of the properties of heat, but from its sensible effects. 
Heat, from whatever medium it proceeds, whether from the sun, or 
atmosphere, from sand or water, from tire, or from any other sub¬ 
stance, is the same—chemically and mechanically the same. It is a 
substance which acts upon the ultimate particles ol bodies, expanding 
them by increase of temperature, and contracting by diminution, 
but to assert that metal and wood are equal conductors ot the heat ol 
one substance, and not of another, is completely opposed to all phil¬ 
osophy. That heat and cold are considered by many as the effect of 
two dill •rent substances, is a truth of which we may be made daily 
sensible, yet, though the sensations be very different, they proceed 
from the same cause ; for instance, if the hand be placed upon a body 
of a higher temperature, the sensation called heat will be felt, and 
