CHAPTER II

THE THEORY OF PHYSICAL ALCHEMY Supposed Proofs of Transmutation. § =14.= It must be borne in mind when reviewing the theories of the alchemists, that there were a number of phenomena known at the time, the superficial examination of which would naturally engender a belief that the transmutation of the metals was a common occurrence. For example, the deposition of copper on iron when immersed in a solution of a copper salt (_e.g._, blue vitriol) was naturally concluded to be a transmutation of iron into copper,[21] although, had the alchemists examined the residual liquid, they would have found that the two metals had merely exchanged places; and the fact that white and yellow alloys of copper with arsenic and other substances could be produced, pointed to the possibility of transmuting copper into silver and gold. It was also known that if water (and this is true of distilled water which does not contain solid matter in solution) was boiled for some time in a glass flask, some solid, earthy matter was produced; and if water could be transmuted into earth, surely one metal could be converted into another.[22] On account of these and like phenomena the alchemists regarded the transmutation of the metals as an experimentally proved fact. Even if they are to be blamed for their superficial observation of such phenomena, yet, nevertheless, their labours marked a distinct advance upon the purely speculative and theoretical methods of the philosophers preceding them. Whatever their faults, the alchemists _were_ the forerunners of modern experimental science. [21] Cf. _The Golden Tract concerning the Stone of the Philosophers_ (_The Hermetic Museum_, vol. i. p. 25). [22] Lavoisier (eighteenth century) proved this apparent transmutation to be due to the action of the water on the glass vessel containing it. The Alchemistic Elements. § =15.= The alchemists regarded the metals as composite, and granting this, then the possibility of transmutation is only a logical conclusion. In order to understand the theory of the elements held by them we must rid ourselves of any idea that it bears any close resemblance to Dalton’s theory of the chemical elements; this is clear from what has been said in the preceding chapter. Now, it is a fact of simple observation that many otherwise different bodies manifest some property in common, as, for instance, combustibility. Properties such as these were regarded as being due to some principle or element common to all bodies exhibiting such properties; thus, combustibility was thought to be due to some elementary principle of combustion--the “sulphur” of the alchemists and the “phlogiston” of a later period. This is a view which _à priori_ appears to be not unlikely; but it is now known that, although there are relations existing between the properties of bodies and their constituent chemical elements (and also, it should be noted, the relative arrangement of the particles of these elements), it is the less obvious properties which enable chemists to determine the constitution of bodies, and the connection is very far from being of the simple nature imagined by the alchemists. Aristotle’s Views regarding the Elements. § =16.= For the origin of the alchemistic theory of the elements it is necessary to go back to the philosophers preceding the alchemists, and it is not improbable that they derived it from some still older source. It was taught by Empedocles of Agrigent (440 B.C. _circa_), who considered that there were four elements--earth, water, air, and fire. Aristotle added a fifth, “the ether.” These elements were regarded, not as different kinds of matter, but rather as different forms of the one original matter, whereby it manifested different properties. It was thought that to these elements were due the four primary properties of dryness, moistness, warmth, and coldness, each element being supposed to give rise to two of these properties, dryness and warmth being thought to be due to fire, moistness and warmth to air, moistness and coldness to water, and dryness and coldness to earth. Thus, moist and cold bodies (liquids in general) were said to possess these properties in consequence of the aqueous element, and were termed “waters,” &c. Also, since these elements were not regarded as different kinds of matter, transmutation was thought to be possible, one being convertible into another, as in the example given above (§ 14). The Sulphur-Mercury Theory. § =17.= Coming to the alchemists, we find the view that the metals are all composed of two elementary principles--sulphur and mercury--in different proportions and degrees of purity, well-nigh universally accepted in the earlier days of Alchemy. By these terms “sulphur” and “mercury,” however, must not be understood the common bodies ordinarily designated by these names; like the elements of Aristotle, the alchemistic principles were regarded as properties rather than as substances, though it must be confessed that the alchemists were by no means always clear on this point themselves. Indeed, it is not altogether easy to say exactly what the alchemists did mean by these terms, and the question is complicated by the fact that very frequently they make mention of different sorts of “sulphur” and “mercury.” Probably, however, we shall not be far wrong in saying that “sulphur” was generally regarded as the principle of combustion and also of colour, and was said to be present on account of the fact that most metals are changed into earthy substances by the aid of fire; and to the “mercury,” the metallic principle _par excellence_, was attributed such properties as fusibility, malleability and lustre, which were regarded as characteristic of the metals in general. The pseudo-Geber (see § 32) says that “Sulphur is a fatness of the Earth, by temperate Decoction in the Mine of the Earth thickened, until it be hardned and made dry.”[23] He considered an excess of sulphur to be a cause of imperfection in the metals, and he writes that one of the causes of the corruption of the metals by fire “is the Inclusion of a burning Sulphuriety in the profundity of their Substance, diminishing them by Inflamation, and exterminating also into Fume, with extream Consumption, whatsoever Argentvive in them is of good Fixation.”[24] He assumed, further, that the metals contained an incombustible as well as a combustible sulphur, the latter sulphur being apparently regarded as an impurity.[25] A later alchemist says that sulphur is “most easily recognised by the vital spirit in animals, the colour in metals, the odour in plants.”[26] Mercury, on the other hand, according to the pseudo-Geber, is the cause of perfection in the metals, and endows gold with its lustre. Another alchemist, quoting Arnold de Villanova, writes: “Quicksilver is the elementary form of all things fusible; for all things fusible, when melted, are changed into it, and it mingles with them because it is of the same substance with them. Such bodies differ from quicksilver in their composition only so far as itself is or is not free from the foreign matter of impure sulphur.”[27] The obtaining of “philosophical mercury,” the imaginary virtues of which the alchemists never tired of relating, was generally held to be essential for the attainment of the _magnum opus_. It was commonly thought that it could be prepared from ordinary quicksilver by purificatory processes, whereby the impure sulphur supposed to be present in this sort of mercury might be purged away. [23] _Of the Sum of Perfection_ (see _The Works of Geber_, translated by Richard Russel, 1678, pp. 69 and 70). [24] _Of the Sum of Perfection_ (see _The Works of Geber_, p. 156). [25] See _The Works of Geber_, p. 160. This view was also held by other alchemists. [26] _The New Chemical Light_, Part II., _Concerning Sulphur_ (see _The Hermetic Museum_, vol. ii. p. 151). [27] See _The Golden Tract concerning the Stone of the Philosophers_ (_The Hermetic Museum_, vol. i. p. 17). The sulphur-mercury theory of the metals was held by such famous alchemists as Roger Bacon, Arnold de Villanova and Raymond Lully. Until recently it was thought to have originated to a great extent with the Arabian alchemist, Geber; but the late Professor Berthelot showed that the works ascribed to Geber, in which the theory is put forward, are forgeries of a date by which it was already centuries old (see § 32). Occasionally, arsenic was regarded as an elementary principle (this view is to be found, for example, in the work _Of the Sum of Perfection_, by the pseudo-Geber), but the idea was not general. The Sulphur-Mercury-Salt Theory. § =18.= Later in the history of Alchemy, the mercury-sulphur theory was extended by the addition of a third elementary principle, salt. As in the case of philosophical sulphur and mercury, by this term was not meant common salt (sodium chloride) or any of those substances commonly known as salts. “Salt” was the name given to a supposed basic principle in the metals, a principle of fixity and solidification, conferring the property of resistance to fire. In this extended form, the theory is found in the works of Isaac of Holland and in those attributed to “Basil Valentine,” who (see the work _Of Natural and Supernatural Things_) attempts to explain the differences in the properties of the metals as the result of the differences in the proportion of sulphur, salt, and mercury they contain. Thus, copper, which is highly coloured, is said to contain much sulphur, whilst iron is supposed to contain an excess of salt, &c. The sulphur-mercury-salt theory was vigorously championed by Paracelsus, and the doctrine gained very general acceptance amongst the alchemists. Salt, however, seems generally to have been considered a less important principle than either mercury or sulphur. The same germ-idea underlying these doctrines is to be found much later in Stahl’s phlogistic theory (eighteenth century), which attempted to account for the combustibility of bodies by the assumption that such bodies all contain “phlogiston”--the hypothetical principle of combustion (see § 72)--though the concept of “phlogiston” approaches more nearly to the modern idea of an element than do the alchemistic elements or principles. It was not until still later in the history of Chemistry that it became quite evident that the more obvious properties of chemical substances are not specially conferred on them in virtue of certain elements entering into their constitution. Alchemistic Elements and Principles. § =19.= The alchemists combined the above theories with Aristotle’s theory of the elements. The latter, namely, earth, air, fire and water, were regarded as more interior, more primary, than the principles, whose source was said to be these same elements. As writes Sendivogius in Part