of the time, tended to disappear, or rather to return toward the ancient superstitions. In the Key to Painting, as in the Egyptian papyrus and the texts of Zosimus, are mentions of prayers to be recited during the operations; and in this way alchemy remained intimately connected with magic in the middle ages as well as in antiquity.
When civilization began to revive during the Latin middle ages, toward the thirteenth century, in the midst of a new organization, our races took up anew the taste for general ideas, and these, in the sphere of chemistry, were sustained by practices, or rather they obtained their support in the permanent problems raised by them. Thus the alchemistic theories were suddenly revived, with new vigor and development, and their progressive evolution, while improving industry, gradually eliminated the superstitions of former times. Thus was finally constituted our modern chemistry, a rational science, established on purely experimental bases. The science was therefore born in its beginning of industrial practices; it kept course with their development during the reign of ancient civilization; when science went down with civilization, practice survived and furnished science a solid ground on which it was able to achieve a new development when the times and the minds had become favorable. The historical connection of science and practice in the history of civilizations is therefore manifest. There is in it a general law of the development of the human mind. — Translated for The Popular Science Monthly from the Revue des Deux Mondes.
ON the 29th of July, 1893, the little village of Harpenden, in Hertfordshire, England, witnessed a rare ceremonial and was stirred by unusual emotions. The presidents of the scientific societies of England were there, with other of the most eminent men of science in the kingdom and foreigners of like standing; while others, their peers, were represented by letters. Mr. Herbert Gardner, M. P. and Minister of Agriculture of the United Kingdom, presided; by his side were the Duke of Devonshire, President of the Royal Agricultural Society; the Duke of Westminster, who, as chairman of the Executive Committee of the Rothamsted Jubilee Fund, might be considered as manager of the business for which the meeting was held; Lord Kelvin, President of the Royal Society; Dr. Michael Foster; Dr. H. E. Armstrong, President of the Chemical Society; Prof. Charles Stewart, President of the Linnæan Society; Sir J. D. Hooker; Sir John