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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

The first object of Dr. Black's enquiry was, whether Magnesia could
be reduced to Quick-lime. To this purpose, he calcined an ounce of
Magnesia in a strong fire. When taken out of the crucible and weighed,
it had lost seven twelfths of its weight. Combined with different
acids, it formed salts of a similar nature to those constituted by the
same acids with the uncalcined powder; but dissolved in them without
the least degree of effervescence.

It slowly precipitated the corrosive sublimate of mercury, in the form
of a black powder; whereas before calcination a dark red precipitate
was formed from the same substance. Mixed with a warm solution of salt
ammoniac, it separated the volatile alkali from the acid; but it made
no separation of an acid from a calcareous earth, nor did it induce
any change upon lime-water; whereas in an uncalcined state, it rendered
quick-lime mild. Lastly, being digested for some hours with water, it
produced not the least alteration in the water.[p]

  [p] In making this experiment some time since, I imagined that Doctor
  Black had been mistaken in this point, and that some impurity in
  the water had prevented the success of his process, for I found the
  water impregnated, as I supposed, with the Magnesia. Flushed with my
  supposed success, I proceeded to make experiments on the lithontriptic
  powers of this water, which I found to be very considerable, acting
  more efficaciously on the human calculus, than either oyster-shell
  lime water, or a dilute solution of soap ley. I communicated this
  interesting intelligence to some of my medical friends; but on
  repeating my experiment several times with different parcels of
  Magnesia, that the truth of the fact might be absolutely ascertained,
  I at last was convinced, to my no small mortification, that what I had
  too sanguinely flattered myself to be a discovery likely to be highly
  serviceable to mankind, was founded on error; and that the properties
  communicated to the water proceeded from some calcareous matter which
  the Magnesia had received by being washed with impure water. I mention
  this as a caution to every young experimentalist, to be extremely
  careful in drawing conclusions. However, as something may be learned,
  even from an unsuccessful experiment, it proves that a very small
  quantity of lime is sufficient to impregnate a large quantity of water;
  for I used the calcined Magnesia, in the same proportion as lime is
  directed for making lime-water, so that very little of it could be
  quick-lime. And as oyster-shell lime water is a superiour solvent of
  the calculus to the water prepared with stone lime, is there not some
  reason to think that the calcareous earth, which has been dissolved in
  hard water, may, when calcined, be a more powerful lithontriptic, than
  either of the others? If any inference can be drawn from it, which may
  in the least promote the interests of mankind, I shall be sufficiently

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