Essays on the Microscope: Containing a Practical Description of the Most Improved Microscopes, a General History of Insects, etc., etc.Adams, George
Science
Essays on the Microscope: Containing a Practical Description of the Most Improved Microscopes, a General History of Insects, etc., etc.
Adams, George
Insects -- Early works to 1800; Microscopy -- Early works to 1800
A great many shoots of the scarlet and other oaks are to be taken off in
the Spring; they must be cut into pieces of about two inches in length,
and immediately from the cutting they must drop into some warm rain
water: in this they are to stand twenty-four hours, and then be boiled a
little. When taken out, they are to be tied on strings, and hung up in a
place where the air passes freely, but the sun does not shine. When they
are perfectly dry, a large quantity of green wax, such as is used for
the seals of law deeds, is to be gently melted in an earthen pipkin set
in water; the water to be heated and kept boiling. As soon as the wax
runs, the sticks are to be put in, and they are frequently to be stirred
about. They must be kept in this state about an hour, and then the
pipkin is to be taken out of the water, and set upon a naked fire, where
it is to be kept with the wax boiling for two or three hours; fresh
supplies of the same wax being added from time to time.
After this it is to be removed from the fire, and the sticks immediately
taken out with a pair of nippers; when they are cold, the rough wax
about them is to be broken off. Both ends of each stick are to be cut
off half an inch long, and thrown away, and the middle pieces saved.
These are then to be cut in smaller lengths, smoothed at the ends with a
fine chissel, and many of them split in various thicknesses.
Thus are obtained preparations, not only of great use, but of wonderful
beauty. Many trees this way afford handsome objects as well as the oak;
and in some, where the sap vessels are few, large, and distinct, the
split pieces resemble striped satins, in a way scarce to be credited. It
is in such that the outer coats of these vessels are most happily of all
to be examined.
THE METHOD OF PREPARING SALTS AND SALINE SUBSTANCES, FOR THE VIEWING
THEIR CONFIGURATIONS.
Dissolve the subject to be examined in no larger a quantity of river or
rain water than is sufficient to saturate it; if it be a body easily
dissoluble, make use of cold water, otherwise make the water warm or
hot, or even boiling, according as you find it necessary. After it is
perfectly dissolved, let it rest for some hours, till, if over-charged,
the redundant saline particles are precipitated, and settle at the
bottom, or shoot into crystals; by which means you are most likely to
have a solution of the same strength at one time as at another; that is,
a solution fully charged with as much as it can hold up, and no more;
and by these precautions the configurations appear alike, how often
soever tried: whereas, if the water be less saturated, the proportions,
at different times, will be subject to more uncertainty; and if it be
examined before such separation and precipitation of the redundant
salts, little more will be seen than a confused mass of crystals.
Public-domain text, read in full here on John Shaqi.
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