Phenix gazette. [volume] (Alexandria [D.C.]) 1825-1833, 1826-03-31
FRIDAY, MARCH 81, 1926.
To the Editors ofthe Phenir Gazette.

2sth, over the signature of"Copernicus," asks
this question" Is cold negative or is it posi-
tiue substance?' He states various reasons
which induce him to believe an affirmative an
swer must be given to the first part OF his que
'ry, and then proceeds to draw, from the fact
supposed TO be established, differences in favor
Of Symmes' Theory Of the Earth. In relation
TO this Theory have nothing to say; but as
"Copernicus" has arrived at conclusion in re-
gard to the nature of cold which appears 10 me
erroneous, will offer few remarks for his
consideration.
In stating the arguments which have induced
philosophers generally" to believe cold is ne
gative quality, he admits one, which think
must have had considerable weight in their
minds, because it is one of importance. We
see the effects produced by heat, and can trace
them with certainty to it as their cause; but all
the effects of cold have ever seen, or heard Of
can as well be accounted for under the SUPPOSE
ton that it is negative, as the oontrary for in
all these we notice the agency of heat, though
not existing in that degree in which it has usu-
ally borne the name Of heat. Until we are able,
metaphoricslly speaking, to hold up to view the
substance under discussion, turn it over, and
examine its various properties, we have strong
reason to believe it does not exist.
This writer adduces the contrast between the
effects produced, by pouring sulphurc acid up
on pounded ice, in one experiment, and into
water, in another, as an argument in favor Of
his conclusion; but he goes upon the SUPPOSE
ton that this phenomenon has never been salts
factorily accounted for. If, in the one case, the
absorption of heat, and in the other, its evolu-
tion'be proven, his argument will fall to the
ground. 1t is law of nature well known to
chemists, that when a substance passes from a
liquid into solid form, or from rare to
denser state Of fuidity, quantity of latent (o
unperceiyed) heat is set free, and thus becomes
apparent TO our senses. The reverse of this
law is equally well known: viz, that when bo-
DIV passes from solid to liquid form, or from
dense to a rarer state of duidity, heat is alb 1
sorbed, rendered latent, insensible. When sui
phuric acid is poured on snow or pounded ice,
the whole mixture becomes liquid; the ice, OF
course, leaves its solid form-it then absorbs
heat; and as the sulphuric acid and the Sur
rounding air have to part with an equal quantl-
ty, this circumstance produces the degree oil
cold which is witnessed. If we pour sulphuric
acid into water, though that water be OF the
same temperature with the ice in the first expe-
riment, ye, contrary effect upon the thermo-
ter is produced, by a change taking place differ
ent from the foregoing. In this instance, the
water unites with the acid, and reaches a enser
state than it was In before. According to the
law above quoted, it parts with portion Gifts
latent heat, which becomes sensible.
1t no doubt appeared singular to "Coperni-
GUS" that from two experiments, results di-
rcctly opposite should proceed, when in each
instance, the same substances, at the same tenn
pera,ure, were mixed together. But there is
great difference between the quantity OF heat
contained in ice and in water. The latter parts
with portion of this substance when it be-
comes converted into the former. If 1t were
not for this, the process Of congelation would
be sudden, instead Of gradual operation
This is rendered more obvious by the fact, that
when by arti6ce fluid is made to crystalize
precipi,stely, considerable rise in temperature
tales place The discovery of this fact, has
placed within the power Of millers plan, by
which they can prevent the accumulation OF ice
upon their water wheels. They erect over the
wheel house Of sufficient extent to cover por-
ton of the stream-this house has double walls,
between which is inserted some substance that
will not conduct heat-During cold weather, a
quantity of this agent is set free from the ice
which forms below, sufficient to keep the tenn
perature of the whole room above SO degrees.
"Copernicus" says, in his second paragraph,
The smallest degree Of heat would be sufficient to
expel cold from the polar regions, were the lat
ter negative quality. We have to take his
word for this, for he adduces no proof 1t is