by means of sulphur and mercury. After this he became a violent anti-Galenist. He studied the works of Paracelsus, and after some years came back to his native country full of ideas and phantasies.
By marrying a wealthy woman Van Helmont became independent, and his scientific career now commenced. He erected and fitted a laboratory at Vilvorde, and devoted his time and skill to the study of chemistry, medicine, and philosophy. He described himself as "Medicus per Ignem," and was one of the most earnest believers in the possibility of discovering the philosopher's stone, and the elixir of life. Indeed he claimed that he had actually transmuted mercury into gold, and by his medical compounds it is alleged that he performed such miraculous cures that the Jesuits actually brought him before the Inquisition.
The advance in chemistry for which he is most famous was the discovery of carbonic acid gas, and the first steps in the recognition of the various kinds of gases. Previous to his discovery chemists had no clear perception of a distinction between the various gases; they reckoned them all as air. Geber and other predecessors of Van Helmont had observed that certain vapours were incorporated in material bodies, and they regarded these as the spirits, or souls, of those bodies. Van Helmont was the first actually to separate and examine one of these vapours. He tracked this gas through many of the compounds in which it is combined or formed: he got it from limestone, from potashes, from burning coal, from certain natural mineral waters, and from the fermentation of bread, wine, and beer. He found that it could be compressed in wines and thus yield the sparkling beverages we know so well. He also observed that it extinguished flame, and asphyxiated
