The Liverpool Standard and General Commercial Advertiser.
Liverpool, Merseyside, England, 1836-12-30 00:00:00

IMPLORES."

From the commencement of our comments upon the admira-
ble lectures of Mr. Hemming, we have never wished ourselves
to be understood as chemical Stagyrites, or infallible Popes,
correcting that gentleman in any one of the many important
truths he brought before his enlightened audience at Liverpool.
We are aware that all we have written, by way of corrigenda,
was within the compass of his own mind, and our only aim has
been to perform the humbler task of altering, or adding a
comma here and there; or, where it would havejeen imprac-
r•-• nr. 11 ty;,a the demonstration ourselves. to W..
the opportunity of displaying the profound depth of our scien-
tific learning, by letting our readers know that we can manage
a proposition of Euclid. Speaking of the sulphuret of mercury,
Mr. H. says, that "the sulphur, at a high heat, leaves the tner-
enry, and combines with the lime," which, in the sense Mr.
intended, is a chemical truth, but, as we are disposed to think a
similar form of expression once gave a practical (though not a
very scientific) chemist a great deal of trouble, and occasioned
some expense, we think it right to draw the attention of our
operative friends to it. It bad been said, that the chlorine of
the chloride of sodium, (common salt,) at a considerable heat,
quitted the sodium to unite with lead—and he thought it pus-
sible, that mere heat itself might expel it, as there seemed, ac-
cording to the phraseology used, to be a state of transit from the
sodium to the lead—his attempts failed, and would never have
been made, had it been stated, that the chlorine, at a high tem-
perature, has a greater affinity only for lead than it has for so-
dium. So here, it is the superior affinity of the lime for the
sulphur, which sets the mercury free. We have, in our pre-
ceding comments, noticed the fact, that mercury is not blackened
by a solution of sulphuretted hydrogen—indeed, if we wished
to procure a hydrosulphuret from a hydroguretted sulphuret, it
would only be necessary to agitate the latter with mercury,
whiclr would take away the excess of sulphur, and leave a co-
lourless hydrosulphuret.

It is a trivial mistake, after stating that "mercury is 131 times
heavier than water," that " one pint of mercury will weigh
nearly as much as a gallon of water "—theta are no gallons
that weigh 13itbs—in fact it weighs more than a gallon and n
half of the old wine measure.

Mercury, Mr. H. states, to " evaporate spontaneously at all
ordinary temperatures above 32°. If this be true, and Dr. Fa-
raday is quoted as an authority—it is a most remarkable coin-
cidence, for as regards the mercurial scale, there is nothing in
what we call 32° of Fahrenheit which is connected with any
apparent change in the habitudes of mercury. It congeals at
about 710 below the freezing point of water, and at no step
from congelation to vaporization do we see any other abrupt
'assumption of new properties. It also clashes with the analogy
of water, which in the state of ice and snow
,(as we frequently
experieuce upon a large scale) rapidly evaporate.
It is sometime since we looked in Boyle, but we do not for a
moment question the accuracy of Mr. H.'s statement that that
philosopher averred, "that be found metallic mercury in the
head of a water gilder." We are perplexed to know where it
was lodged, except in soma of the sinuses of the brain. This
"water-gilder" would have proved a puzzling subject to the
disciples of Gall and Spurzheim, for in whatever cavity it was
lodged, frontal, parietal, or occipital, he mist have been an in-
tellectual, a moral, or a physical Mercury.-
.
We know not of any case where metallic mercury is taken up
by the absorbents—and it seems equally incapable of being re-
ceived in that state by the lacteals ; if, therefore, it be inhaled
by the lungs, we may suppose it eaters the circulation through
some of the capillaries of the pulmonic artery, but thee, most
probably, in the state of ae oxide, from the circumstance of its
extreme division in the form of vapour, and its exposure to the
Oxygen of the inspired air. How it becomes disoxygenized is
difficult to explain, and,. if any where, it must be i❑ the brain
itself, tot metallic mercury could not continue suspended in the
blood.

The experiment of Dr. Priestley with the peroxide of cuercu.
ry, not only furnishes the chemist with oxygen gas, but also
serves to demonstrate the existence of the disoxygenizing rays
in solar although that philosopher did not draw that con-
clusion from it. There heat would only have driven off one
atom of the peroxide—leaving the protuxide, of which Mr. H.
makes mention afterwards.

The peroxide of mercury, Mr. 11. observes, is sometimes
mixed with " red lead," and that " this we can easily detect by
heating a portion of it, when the peroxide of mercury will be
dissipated, and the lead, if any, left behind as a yellow oxide."
We apprehend some little error here ; it is, as we know, from
many experiments, very difficult to obtain the yellow oxide of
lead free from the red oxide, and, in the present case, there is
no reason why it should pass from the state of red to yellow
oxide.

Aualagous to the case mentioned by Mr. IL, of I3asil Valen-
tine, is that of a patient on his voyage to India. bit related by
Dr. Johnson, the erudite editor of the Medico-Chirurgical
Review, who w.ts ordered to take some pills containing calomel.
The patient, however, feeling very much disinclined to physic
of any kind, amused himself by throwing the pills every morning
into the chicken coop, which the unsuspecting birds picked up,
mistaking them for peas. In a short time all the feathers came
off them, to the surprise of every one on board; but, as there
seemed uo disease among them, they were preserved ftom the
kuife. They soon because fatter and finer fowls than had ever
been seen at sea., and then, we think, the patient :mentioned the
mediae treatment they had undergone. Whether this fact be
worth knOoin; to our poultry farmers, or whether it wtst:d