available source of energy for suburban traffic, at least, that
this generation should only be fulfilling the idea of the old Franciscan
friar of the thirteenth century, who prophesied that in explosives there
was the secret of eventually manageable energy for transportation
purposes.

Succeeding centuries were not as fruitful in great scientists as the
thirteenth, and yet, in the second half of the thirteenth, there was a
Pope, John XXI, who had been a physician and professor of medicine
before his election to the Papacy, three of whose scientific
treatises--one on the transmutation of metals, which he considers an
impossibility, at least as far as the manufacture of gold and silver was
concerned; a treatise on diseases of the eyes, to which good authorities
have not hesitated to give lavish praise for its practical value,
considering the conditions in which it was written; and, finally, his
treatise on the preservation of the health, written when he was himself
over eighty years of age--are all considered by good authorities as
worthy of the best scientific spirit of the time.

During the fourteenth century, Arnold of Villanova, the inventor of
nitric acid, and the two Hollanduses, kept up the tradition of original
investigation in chemistry. Altogether there are some dozen treatises
from these three men on chemical subjects. The Hollanduses particularly
did their work in a spirit of thoroughly frank, original investigation.
They were more interested in minerals than in any other class of
substances, but did not waste much time on the question of transmutation
of metals. Professor Thompson, the professor of chemistry at Edinburgh,
said, in his "History of Chemistry," many years ago, that the
Hollanduses give very clear descriptions of their processes of treating
minerals in investigating their composition, and these serve to show
that their knowledge was by no means entirely theoretical, or acquired
only from books.

It is not surprising, then, to have a great investigating pharmacologist
come along sometime about the beginning of the fifteenth century, when,
according to the best authorities, Basil Valentine was born. From
traditions he seems to have had a rather long life, and his years run
nearly parallel with his century. His career is a typical example of the
personally obscure and intellectually brilliant lives which the old
monks lived. Probably in nothing have recent generations been more
deceived in histor