Part 5 (2/2)

In their search for ”the pure and penetrating matter which applied to any substance exalts and perfects it after its own kind,” the alchemists necessarily made many inventions, laid the foundation of many arts and manufactures, and discovered many facts of importance in the science of chemistry.

The pract.i.tioners of the _Sacred Art_ of Egypt must have been acquainted with many operations which we now cla.s.s as belonging to applied chemistry; witness, their jewellery, pottery, dyes and pigments, bleaching, gla.s.s-making, working in metals and alloys, and their use of spices, essential oils, and soda in embalming, and for other purposes.

During the centuries when alchemy flourished, gunpowder was invented, the art of printing was established, the compa.s.s was brought into use, the art of painting and staining gla.s.s was begun and carried to perfection, paper was made from rags, practical metallurgy advanced by leaps and bounds, many new alloys of metals came into use, gla.s.s mirrors were manufactured, and considerable advances were made in practical medicine and sanitation.

[Ill.u.s.tration: FIG. XI. _See p. 92._]

Basil Valentine, who was one of the greatest alchemists of the 16th century, discovered many of the properties of the metal antimony, and prepared and examined many compounds of that metal; he made green vitriol from pyrites, brandy from fermented grape-juice, fulminating gold, sulphide of potash, and spirits of salt; he made and used baths of artificial mineral waters, and he prepared various metals by what are now called _wet methods_, for instance, copper, by immersing plates of iron in solutions of bluestone. He examined the air of mines, and suggested practical methods for determining whether the air in a mine was respirable. Hoefer draws attention to a remarkable observation recorded by this alchemist. Speaking of the ”spirit of mercury,” Basil Valentine says it is ”the origin of all the metals; that spirit is nothing else than an air flying here and there without wings; it is a moving wind, which, after it has been chased from its home of Vulcan (that is, fire), returns to the chaos; then it expands and pa.s.ses into the region of the air from whence it had come.” As Hoefer remarks, this is perhaps one of the earliest accounts of the gas discovered by Priestley and studied by Lavoisier, the gas we now call oxygen, and recognise as of paramount importance in chemical reactions.

[Ill.u.s.tration: FIG. XII. _See p. 92._]

Besides discovering and recording many facts which have become part and parcel of the science of chemistry, the alchemists invented and used various pieces of apparatus, and conducted many operations, which are still employed in chemical laboratories. I shall reproduce ill.u.s.trations of some of these processes and pieces of apparatus, and quote a few of the directions, given in a book, published in 1664, called _The Art of Distillation_, by John French, Dr. in Physick.

The method recommended by French for hermetically sealing the neck of a gla.s.s vessel is shown in Fig. VI. p. 80. The neck of the vessel is surrounded by a tray containing burning coals; when the gla.s.s melts it is cut off by shears, and then closed by tongs, which are made hot before use.

Fig. VII. p. 81, represents a method for covering an open vessel, air-tight, with a receptacle into which a substance may be sublimed from the lower vessel. The lettering explains the method of using the apparatus.

French gives very practical directions and much sound advice for conducting distillations of various kinds. The following are specimens of his directions and advice:--

”When you put water into a seething Balneum wherein there are gla.s.ses let it be hot, or else thou wilt endanger the breaking of the gla.s.ses.

”When thou takest any earthen, or gla.s.s vessel from the fire, expose it not to the cold aire too suddenly for fear it should break.

”In all your operations diligently observe the processes which you read, and vary not a little from them, for sometimes a small mistake or neglect spoils the whole operation, and frustrates your expectations.

”Try not at first experiments of great cost, or great difficulty; for it will be a great discouragement to thee, and thou wilt be very apt to mistake.

”If any one would enter upon the practices of Chymistry, let him apply himself to some expert artist for to be instructed in the manual operation of things; for by this means he will learn more in two months, than he can by his practice and study in seven years, as also avoid much pains and cost, and redeem much time which else of necessity he will lose.”

Fig. VIII. p. 82, represents a common cold still, and Fig. IX. p. 84, is a sketch of an apparatus for distilling by the aid of boiling water. The bath wherein the vessels are placed in Fig. IX. was called by the alchemists _balneum Mariae_, from Mary the Jewess, who is mentioned in the older alchemical writings, and is supposed to have invented an apparatus of this character. Nothing definite is known of Mary the Jewess. A writer of the 7th century says she was initiated in the sacred art in the temple of Memphis; a legend prevailed among some of the alchemists that she was the sister of Moses.

Fig. X. p. 85, represents methods of distilling with an apparatus for cooling the volatile products; the lower vessel is an _alembic_, with a long neck, the upper part of which pa.s.ses through a vessel containing cold water.

[Ill.u.s.tration: Fig XIII. _See p. 94._]

Fig. XI. p. 88, shows a _pelican_, that is a vessel wherein a liquid might be heated for a long time, and the volatile products be constantly returned to the original vessel.

Fig. XII. p. 89, represents a retort with a receiver.

Some of the pieces of apparatus for distilling, which are described by French, are shown in the following figures. Besides describing apparatus for distilling, subliming, and other processes in the laboratory, French gives directions for making tinctures, essences, essential oils, spirits of salt, and pure saltpetre, oil of vitriol, b.u.t.ter of antimony, calces (or as we now say, oxides) of metals, and many other substances. He describes processes for making fresh water from salt, artificial mineral water, medicated hot baths for invalids (one of the figures represents an apparatus very like those advertised to-day as ”Turkish baths at home”), and artificial precious stones; he tells how to test minerals, and make alloys, and describes the preparation of many substances made from gold and silver. He also gives many curious receipts; for instance, ”To make Firre-trees appear in Turpentine,” ”To make a Plant grow in two or three hours,” ”To make the representation of the whole world in a Gla.s.s,” ”To extract a white Milkie substance from the raies of the Moon.”

[Ill.u.s.tration: FIG. XIV. _See p. 94._]

The process of making oil of vitriol, by burning sulphur under a hood fitted with a side tube for the outflow of the oil of vitriol, is represented in Fig. XIII. p. 92.

Fig. XIV. p. 93, is interesting; it is an apparatus for rectifying spirits, by distilling, and liquefying only the most volatile portions of the distillate. The spirituous liquor was heated, and the vapours caused to traverse a long zigzag tube, wherein the less volatile portions condensed to liquid, which flowed back into the vessel; the vapour then pa.s.sed into another vessel, and then through a second zigzag tube, and was finally cooled by water, and the condensed liquid collected. This apparatus was the forerunner of that used to-day, for effecting the separation of liquids which boil at different temperatures, by the process called _fractional distillation_.

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