The Liverpool Standard and General Commercial Advertiser.
Liverpool, Merseyside, England, 1855-08-14 00:00:00

SCIENCE AND ART.

WHILE ENGAGED IN READING OR WRITING, acts
during which we are apt to hold in the breath without
being conscious of it, we should frequently make deep
aspirations, rise from the table, and take a few turns
across the room. When occupied with any matter
requiring close attention, we should close our eyes
every now and then for a few minutes. The physician
will understand the reason for this advice, and the
non-professional reader will do well to follow it.
EARLY RISING.—Dr. Wilson Philip, in his "Treatise
on Indigestion," says—" Although it is of consequence
to the debilitated to go early to bed, there are few
things more hurtful to them than remaining in it too
long. Getting up an hour or two earlier often gives
a degree of vigour which nothing else can procure.
For those who are not much debilitated and sleep well,
the best rule is to get out of bed soon after waking in
the morning. This at first may appear too early, for
-the debilitated require 'more sleep than the healthy;
but, rising early will gradually prolong the sleep on
the succeeding night, till the quantity the patient en-
joys is equal to his demand for it. Lying late is not
only hurtful by the relaxation it occasions, but also by
occupying that part of the day at which exercise is
most beneficial."

DIFFUSENESS OF PERFUMES.—One circumstance
which presses very strongly upon our attention, is the
extremely minute state of diffusion in which the
odoriferous substances of animal origin still make
themselves perceptible to our senses. A fragment of
musk not only gives off a strollg smell when it is first
exposed to the air, but it continues to do so for an
almost indefinite period of time. Yet the odour must
be caused by particles of matter which are continu-
ously escaping from the musk, so long as it continues
exposed to the air. How inconceivably small in
weight, how infinitely minute in 'size, the molecules
must be of which this constantly-flowing stream of
matter consists ! And to vegetable perfumes the same
observations almost equally • apply A morsel of cam-
phor will for days fill a large room with its scent
without suffering any material diminution in weight.
A single leaf of melilot will for years preserve and
manifest its sweet odour, and yet the quantity of cou-
marin it contains would most probably be inappreciable
by the most delicate balance. We know in this country
how a stalk of mignonette, placed in an open window,
will scent the air that enters, through the whole of a long
summer's day. But in hot climates, especially during
the morning and evening hours, this diffusiveness of
perfumes is still more striking. The odour of the
balsam-yielding Humtriads has been perceived at a
distance of three miles from the shores of South
America—a species of Tetracera sends its perfume as
far from the island of Cuba—and the aroma of the
Spice Islands is wafted out to sea. The quantity of
ethereal oil which gives its peculiar aroma to grape-
wine has been estimated at one-forty-thousandth only
of the bulk of the wine, and that which gives the
aroma to roasted coffee, at one-fifty-thousandth of its
weight ; but the ozone Which exists in the atmosphere