[70] Alcahest, in chemistry, (an obsolete term,) means a most pure and universal menstruum or dissolvent, with which some chemists have pretended to resolve all bodies into their first elements, and perform other extraordinary and unaccountable operations.

solvent, menstruum, alkahest^. V. render liquid &c 333; liquefy, run; deliquesce; melt &c (heat) 384; solve; dissolve, resolve; liquate^; hold in solution; condense, precipitate, rain.

The magnificent constituency of mediocrities of which the world is made up,the people without biographies, whose lives have made a clear solution in the fluid menstruum of time, instead of being precipitated in the opaque sediment of history

It is by the power of friction; that is to say, the two wheels, or paddles turning diametrically, or at the same moment, on their axioms, and repressing by the rotundity of their motion the action of the menstruum in which the machine floats,water being, in a philosophical sense, a powerful non-conductor,it is clear, that in proportion as is the revulsion so is the progression; and as is the centrifugal force, so is the.

Impure spirits of 40° Gay-Lussac, and not water, should be used as a menstruum for the salt of copper.

Others take either the English or the Latin plural; as, desideratums or desiderata, mediums or media, menstruums or menstrua, memorandums or memoranda, spectrums or spectra, speculums or specula, stratums or strata, succedaneums or succedanea, trapeziums or trapezia, vinculums or vincula.

Among the Rosicrucians, who have, by some, been improperly confounded with the Freemasons, the word lux was used to signify a knowledge of the philosopher's stone, or the great desideratum of a universal elixir and a universal menstruum.

L. E. D.-Poppy heads, boiled in water, impart to the menstruum their narcotic juice, together with the other juices which they have in common with vegetable matters in general.

Mr. Cathery has much improved and simplified the process, by covering the ivory with engraver's varnish, and drawing the design with an etching needle; he then pours on a menstruum, composed of 120 grains of fine silver, dissolved in an ounce measure of nitric acid, and diluted with one quart of pure distilled water.