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Experiments and Observations on the Following Subjects: 1. On the preparation, calcination, and medicinal uses of Magnesia Alba. 2. On the solvent qualities of calcined Magnesia. 3. On the variety in the solvent powers of quick-lime, when used in different quantities. 4. On various absorbents, as promoting or retarding putrefaction. 5. On the comparative antiseptic powers of vegetable infusions prepared with lime, &c. 6. On the sweetening properties of fixed air. — John Shaqi

Science

Experiments and Observations on the Following Subjects: 1. On the preparation, calcination, and medicinal uses of Magnesia Alba. 2. On the solvent qualities of calcined Magnesia. 3. On the variety in the solvent powers of quick-lime, when used in different quantities. 4. On various absorbents, as promoting or retarding putrefaction. 5. On the comparative antiseptic powers of vegetable infusions prepared with lime, &c. 6. On the sweetening properties of fixed air.

Name: Experiments and Observations on the Following Subjects: 1. On the preparation, calcination, and medicinal uses of Magnesia Alba. 2. On the solvent qualities of calcined Magnesia. 3. On the variety in the solvent powers of quick-lime, when used in different quantities. 4. On various absorbents, as promoting or retarding putrefaction. 5. On the comparative antiseptic powers of vegetable infusions prepared with lime, &c. 6. On the sweetening properties of fixed air.
Author: Henry, Thomas

Henry, Thomas

Lime -- Early works to 1800; Magnesium carbonate -- Early works to 1800; Magnesium carbonate -- Therapeutic use -- Early works to 1800; Putrefaction -- Early works to 1800

recompensed for the humiliating circumstance of recounting an erroneous
  experiment.

In pursuing his inquiries, he found that a very small portion of what
had been lost in the calcination was water, and that the other part
was fixed air, by the loss of which the Magnesia was deprived of its
power of effervescing with acids. And from hence the Doctor concluded,
that the change made in calcareous substances and in Magnesia by
calcination, was chiefly produced by depriving them of this air; and
that this volatile Proteus may be conveyed from one body containing it
to another body with which it has a greater affinity.

Thus lime being deprived of its air by calcination, and having a
stronger affinity with it than alkaline salts have, being mixed with a
lixivium of these salts, absorbs all the air from them, deprives them
of their property of effervescing with acids, and renders them more
acrid, at the same time that the lime becomes mild, and incapable of
impregnating water, but recovers its power of fermenting when mixed
with an acid.




CHAP. V.

ON THE MEDICINAL VIRTUES OF CALCINED MAGNESIA.


Frequent objections have been made to the use of Magnesia Alba, on
account of the great quantity of air which enters into its composition.
Whenever it meets with an acid in the stomach they immediately unite;
but in forming this union, all the air contained in the Magnesia
is discharged with a great degree of effervescence, and recovering
its elasticity sometimes occasions very uneasy sensations in weak
bowels,[q] inflating and distending them overmuch, inducing griping
pains, and above all a sense of debility or sinking, which is not
easily described.

  [q] Neque tamen præterire possumus, id incommodi nos quandoque ab hoc
  Magnesiæ pulvere deprehendisse, quod flatulentias et morsicationes
  in imo ventri reliquerit, si videlicet frequentius in usum trahatur,
  primaque regio progignendis corrosivis succis, ut in hypochondriacis
  fieri solet, exposita sit.

    Hoffman. Oper. Tom. 4. p. 381.

My much respected friend Doctor Percival, who had often complained of
these disagreeable effects from the use of Magnesia, suggested to me
the idea of depriving it of its fixed air by calcination, having been
informed that they would be obviated by this method. Doctor Black
had indeed proved the practicability of the process, but he does not
appear to have made trial of the calcined Magnesia as a medicine.
In consequence of the above hint I calcined some Magnesia, and was
afterwards insensibly led to make further experiments, the event of
which, I hope, will be deemed of sufficient importance to apologize for
my communicating them to the public.


EXPERIMENT I.

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