Page:Edward Thorpe — History of Chemistry, Volume I (1909).pdf/56

40 personal history of alchemy, to divide it into the two periods before and after Paracelsus, since under his inspiration and example alchemy underwent a great development as regards its professed objects. These eventually became so extravagant that, wide as are the limits of human credulity, its pretensions gradually brought it into disrepute, and it fell by the weight of its own absurdities.

One of the most reputable of the early Western alchemists was Albert Groot, or Albertus Magnus, born at Lauingen in 1193. He was a Dominican monk, who became Bishop of Regensburg, but, resigning his bishopric, retired to a convent at Cologne, where he devoted himself to science until his death in 1282. He is credited with having written a number of chemical.tracts, for the most part in clear and intelligible language, which is more than can be said of the greater portion of alchemistical literature. He gives an account of the origin and main properties of the chemical substances known in his time, and describes the apparatus and processes used by chemists, such as the water-bath, alembics, aludels, and cupels. He speaks of cream of tartar, alum and caustic alkali, red lead, liver of sulphur and arsenic, green vitriol and iron pyrites.

Contemporaneously with him was Roger Bacon, Doctor Mirabilis, one of the most erudite