582 
WOOD and metal conductors or HEAT. 
ARTICLE III. 
COMPARATIVE REMARKS ON WOOD AND METAL AS CONDUC¬ 
TORS OF HEAT. 
BY EPHEUICUS IIORTICULTOR. 
I was happy to hear you invite practical men to come forward and 
state their opinions upon disputed subjects, and pleased to see your 
invitation complied with. The different sentiments of individuals 
will be thus brought to bear immediately upon each other, and we 
shall more easily gain the acquisition of truth, provided those sen¬ 
timents are established by adequate reasons, and not bare affirmations, 
said to he the result of experience. I cannot hut admire the liberal 
and candid manner in which some Gardeners have given their 
opinions, whilst at the same time I must disapprove of the weak 
reasoning, and hasty inferences of others. As an example, I would 
allude to the communication of Mr. Cur on Metallic Hothouses— 
He says, “The chief objection urged against metal is the attraction 
of heat. This is mere nonsense, for if the metal is kept well 
painted, it attracts no more heat than wood.” This he proved by 
taking a piece of metal and a piece of wood, both well painted, and 
placing them against a south wall two feet asunder. He examined 
them every half hour, and could not perceive that the metal heated 
one degree faster than the wood; they were also put into water, and 
the one was heated just as soon as the other. Mr. Cur having de¬ 
tailed his experiment, triumphantly exclaims thus: “So much for 
the attraction of heat, which Mr. M. Murtrie says injured his pines 
when they came in contact with the rafters ! ” 
From this experiment, Mr. Cur asserts, that metal and wood are 
equal conductors of heat if kept well painted, for I suppose their 
power of conducting heat is what is meant by their attracting heat. 
This I flatly deny; in the first place, because it is contrary to well 
known properties of caloric ; and secondly, because the experiment 
in itself is erroneous and quite incapable of supporting the inferences 
which Mr. Cur has boldly deduced from it; the great error 
of this experiment lies in Mr. Cur making his observation on the 
same side he applied the heat, if he had felt the opposite sides he 
would have found a great difference; by his plunging them over 
head in water, nothing else could be expected, but that they would 
become equally heated, as there would be a constant giving and re¬ 
ceiving of caloric, till they all three were of a uniform temperature. 
