iversity
of Oxford. Roger Bacon defined the limits of chemistry very accurately
and showed that he understood exactly what the subject and methods of
investigation must be, in order that advance should be made in it. Of
chemistry he speaks in his "Opus Tertium" in the following words:
"There is a science which treats of the generation of things from
their elements and of all inanimate things, as of the elements and
liquids, simple and compound, common stones, gems and marble, gold and
other metals, sulphur, salts, pigments, lapis lazuli, minium and other
colors, oils, bitumen, and infinite more of which we find nothing in
the books of Aristotle; nor are the natural philosophers nor any of
the Latins acquainted with these things."

The thirteenth century saw the rise of a number of great physical
scientists, who made observations that anticipated much more of our
modern views on scientific problems than is usually thought. One of
the greatest of the chemists of the thirteenth century was Albert the
Great, or Albertus Magnus, as he is more familiarly called, who taught
for many years at the University of Paris. He was a theologian as well
as a physician and a scientist. His works have been published in
twenty-one folio volumes, which will give some idea of the immense
industry of the man. Those relating to chemistry are as follows:
Concerning Metals and Minerals; Concerning Alchemy; A Treatise on the
Secrets of Chemistry; A Brief Compend on the Origin of the Metals; A
Concordance, that is, a Collection, of Observations from Many Sources,
with Regard to the Philosopher's {135} Stone; A Treatise on Compounds;
a book of eight chapters on the Philosopher's Stone. Most of these are
to be found in his works under the general heading "Theatrum
Chemicum." Thomson, in his "History of Chemistry," says, that they
are, in general, plain and intelligible. Albertus Magnus's most famous
pupil was the celebrated Thomas Aquinas. Three of his works are on
chemistry: The Intimate Secrets of Alchemy; on the Essence and
Substance of Minerals; and finally, later in life, the Wonders of
Alchemy. It is in this last work, it is said, that the word _amalgam_
occurs for the first time. While Thomas Aquinas and Albertus Magnus
were working in France and Germany, Roger Bacon was doing work of
similar nature at Oxford in England. Altogether, he has eighteen
treatises on chemical problems. Some of these contain wonderful
anticipations of modern chemis