presentation of a petition to be perused, not
under the rose, but under the microscope.
But, in short, without being nice as to a
sixpence or a shilling, it is convenient to be
able to order microscopic preparations of
objects that invite your attention. Thus, I
am awaiting the mouth of a medicinal leech,
to be better enabled to inspect its lancets
and pump; and, having discovered for myself
what others, no doubt, have discovered
before—namely, that the mouth of the
tadpole is not only armed with cutting teeth,
but has two or three rows of lips outside,
that are garnished with a fringe of toothlike
moustaches—I have requested a preparation
to be made, regardless of expense,
for the better examination of my tadpole's
gums.

Amongst continental preparers, Joseph
Bourgogne, of Rue Notre-Dame, Paris, stands
preeminent. He is a man whose whole soul
is in his art, and he naturally speaks of
microscopic preparation as one of the most
important aids to science. He has had the
great advantage of constant communication
with the most learned men of Paris, who
have aided him in their several departments.
From Robin, he has had lessons in anatomy;
from Thuret, in the structure of algæ. Of
late, his health has become impaired in
consequence of severe application, while his
business is steadily on the increase. He
proposes, therefore, to divide his grand
microscopic empire into three kingdoms—the
mineral, the vegetable, and the animal—one
of which he will bequeath to each of his three
sons. M. Bourgogne discovered the male of
the human itch-insect, which discovery made a
great sensation at the time, not having been
seen before. It seems to have been
completely unknown until eighteen 'forty, probably
because it is never found in the furrows of
the skin, as the female always is. Nobody
then suspected that the male lived constantly
on the surface of the epidermis; being also
smaller than the female, it escaped observation.
Ten years afterwards, amongst three
hundred of these insects, which Monsieur B.
had received in several lots, he recognised a
single male by its agility, and by its fourth
pair of paws, which had suckers at their
tips, instead of long bristles, like the female.
He valued the precious acarus as a rarity,
and it formed part of his collection at the
London exhibition in 'fifty-two. But, Dr.
Bourguignon had the indiscretion and the
hardihood to publish a pamphlet denying the
existence of this male acarus, as well as of
the acarus of the rabbit, and others. M.
Bourgogne, urged by his friends, started for
London, and established the truth of the fact
by bringing back the treasured object, and
having a drawing made from it, which
appeared in the Annales des Maladies de la
Peau. And then, visiting the hospital of St.
Louis, he captured several males on the skin
of patients, in the presence of Dr. Hardy
and sundry medical students. The question
was of considerable theoretical and physiological
importance—touching, as it did,
spontaneous generation and the reproduction
of parasites in general. M. Bourgogne
proved that itch-insects are males and
females.

M. Bourgogne's best preparations are
excellent, with the merit of being determined and
named; his inferior preparations are very
indifferent, full of bubbles and dirt. For inspection
by persons who have had a certain experience,
some of these cheap French preparations
are useful; but, as articles of luxury and
ornamental art, the English are superior. M.
Bourgogne classes his productions into first,
second, and third-choice specimmens. When
Beau Brummel's valet came down-stairs from
dressing his master for dinner, he generally
brought with him an armful of discarded white
cravats. "These", he explained, "are our
failures." Just so we may suppose that M.
Bourgogne's third-choice preparations—some
of them as low as threepence-halfpenny each
(what can you expect for threepence halfpenny?)
are, what he is too prudent, as
well as too honest, to sell at higher prices;
"our failures," in short. And, as good
French preparations are costly, while bad
ones are not cheap, an English collector has
no motive to go out of his own country,
unless perhaps it be for some novelty in the
way of morbid anatomy, or other exceptional
cases.

A microscopic museum should be formed
on somewhat the same priciple as a picture
gallery: First, there should be nothing but
what is good; secondly, there should be
variety, with several samples of all the great
masters. Preparers who have been in the
habit of collecting during several years have
each of them, probably, in his secret storehouse,
some treasure whose native habitat,
or source has baffled the research of competing
collectors. To some, the superiority of
certain instruments, or special adroitness,
may give the superiority in certain classes of
objects. The microscopist will profit by all
these in turn. The field of nature is so
vast, that every student may gratify his own
peculiar taste. It is desirable to have some
sequence and connection in the objects
collected. Thus, we may have preparations of
the principal organs of the domestic fly, to
illustrate its economy; the eye, the proboscis,
the foot, the spiracle, and other parts of its
bodily frame. The scales of butterflies and
other insects afford ample subjects for
comparison; the cuticles of plants, showing their
stomata, or perspiring holes; sections of
bones and teeth; starches from various
plants; feathers, hairs, and innumerable
other things will suggest themselves. A
good selection of the spiracles, or breathing-holes
in the sides of different larvæ and
insects would afford a series of objects to which
there is nothing similar in birds and beasts.