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, butter 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 Glass," "To extract a white Milkie substance from the raies of the Moon." [Illustration: 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.