Alchemists; From Al and Chemi, fire, or the god and patriarch, Kham, also, the name of Egypt. The Rosicrucians of the middle ages, such as Robertus de Fluctibus (Robert Fludd), Paracelsus, Thomas Vaughan (Eugenius Philalethes), Van Helmont, and others, were all alchemists, who sought for the hidden spirit in every inorganic matter. Some people— nay, the great majority—have accused alchemists of charlatanry and false pretending. Surely such men as Roger Bacon, Agrippa, Henry Khunrath, and the Arabian Geber (the first to introduce into Europe some of the secrets of chemistry), can hardly he treated as impostors— least of all as fools. Scientists who are reforming the science of physics upon the basis of the atomic theory of Democritus, as restated by John Dalton, conveniently forget that Democritus, of Abdera, was an alchemist, and that the mind that was capable of penetrating so far into the secret operations of nature in one direction must have had good reasons to study and become a Hermetic philosopher. Olaus Borrichius says that the cradle of alchemy is to be sought in the most distant times. (Isis Unveiled).
Source: H.P.Blavatsky - The Theosophical Glossary