The Romance of Modern Chemistry

THE PHILOSOPHER’S STONE supposed to differ from another only in the proportion of mercury and sulphur which it contained; thus gold was particularly rich in mercury, whereas the common metals had a large proportion of sulphur. On this view it ought to be possible to change one metal into another by merely altering the relative proportion of the two constituents, and the problem of transmuting lead or copper into gold would then be reduced to the discovery of some agent which would withdraw sulphur from the baser metal and add mercury to it. That this way of looking at things should be accepted at all is perhaps not so very strange when we consider what the thinkers of a thousand years ago had inherited from Aristotle and other ancient philosophers. We have seen that Aristotle regarded fire, air, earth, and water as different properties carried by one original kind of matter, and it is not a very big step from this view to the belief that by simply modifying its properties one kind of matter could be converted into another kind. Since water was regarded as moist and cold, while air was moist and warm, it was thought possible by heat alone to convert the second chief property of water into the second chief property of air; that is, it was believed that water could be transformed into air. So we see that the views of Geber and the alchemists who followed him in the Middle Ages were more or less a natural development of the speculations of the ancient philosophers. What is difficult to understand is how the belief in the transmutation of metals continued to dominate the study of chemistry so long as it did, for it was not until the beginning of the eighteenth cen- tury that chemists became generally sceptical about the possibility of converting base metal into gold. For the r 23