The Flemish chemist and physician Jan Baptista van Helmont (1580-1644) attempted to construct a natural philosophical system based on chemical concepts. He also developed the concept of gas.

Jan Baptista van Helmont was born of a noble family in Brussels in January 1580. He studied the classics at the University of Louvain until 1594, but he did not accept a degree because he considered academic honors a mere vanity. He also studied aspects of magic and mystical philosophy in courses given by Jesuit teachers at their recently founded Louvain school, and then he turned to the study of such mystical spiritual writers as Thomas à Kempis. Dissatisfied with all these studies, he turned to medicine. In his new undertaking he was inspired by religious zeal and by the desire to be of service to society.

After obtaining his license to practice, Van Helmont was invited to lecture on surgery at the University of Louvain. However, he contracted a case of scabies and found the orthodox treatment by harsh purgatives to be debilitating and ineffective. He was eventually cured by Paracelsian mineral remedies, but meanwhile, disillusioned with the medical science of the time, Van Helmont abandoned his medical career and for 10 years traveled through Europe. He married a wealthy noblewoman, Margaret van Ranst, in 1609 and settled on an estate in Vilvorde near Brussels to devote himself to chemical philosophy.

Following the publication of his treatise on the magnetic cure of wounds, which was directed against a Jesuit, Van Helmont came to the attention of the Inquisition. A charge was brought against him, and this affair cast a shadow over the remainder of his life, which ended on Dec. 30, 1644; he was not acquitted until 2 years after his death. This circumstance possibly made him reluctant to publish much during his lifetime. His son Franciscus Mercurius published his papers posthumously in 1648 under the title Ortus medicinae (Origins of Medicine).

Van Helmont lived precisely in that era of the 17th century when modern scientific method based upon observation and experiment was being forged, but as yet science was not identified either uniquely or exclusively with this approach. For Van Helmont knowledge was a divine gift of God: there was no one way to understand the creation; man had to utilize all the means God had given him, including study of the Scriptures, prayer, meditation, mystical illumination, and direct observation of nature. Like most Paracelsians, Van Helmont distrusted the dialectical mode of reasoning that the scholastic philosophers of the Middle Ages used and the natural philosophy of the Greeks. Experience, both mystical and empirical, was the route to knowledge, not verbal reasoning.

Theory of the Elements

These varied aspects of Van Helmont's thought are nowhere better illustrated than in his theory of the elements. Rejecting the four elements, earth, air, fire, and water, of Aristotle and the three principles, salt, sulfur, and mercury, of Paracelsus, Van Helmont settles on two elements as the basic constituents of the material universe: air and water. Only one of the elements, water, undergoes chemical change: air is simply a physical matrix which contains various vapors and exhalations but does not enter into chemical combination. All material substances, with the exception of air, are thus modified forms of water.

Van Helmont found support for his elemental water theory in the account of creation given in Genesis. To account for the diversity of material forms derived from the primal water, Van Helmont postulated a series of directing and generating principles which he called ferments or seminal principles. They were links between the material world and the spiritual world and as such had a key place in Van Helmont's natural philosophy.

Van Helmont tried to demonstrate his water theory by means of quantitative experiment. He planted a tree in a pot containing a weighed amount of earth. For 5 years he nourished the tree only with water. He found that the weight of the tree had gained 164 pounds while the weight of the earth in the pot was approximately the same as at the beginning of the experiment. He thus attributed the increase in weight of the tree to the assimilation and transformation of water into the substance of the tree.

Concept of Gas

Van Helmont's concept of gas, a word he coined from the Greek chaos, was an integral part of his water-ferment theory of matter. He recognized gases as specific individual chemical entities distinguished from air, but here the comparison with the modern chemical idea of gas ends. A gas to Van Helmont was primal water modified by a specific ferment: each body in nature contains such a gas and under specific conditions, for example, by heating, this gas can be liberated. Van Helmont described the production of such a gas. After burning 62 pounds of charcoal, only 1 pound of ashes remained. He assumed the other 61 pounds had changed into a wild spirit or gas (he called it gas sylvestre) that could not be contained in a vessel. He obtained the same gas by burning organic matter and alcohol and by fermenting wine and beer.

Ferments also play a major role in Van Helmont's biological and medical theories. He hypothesized that each of the principal organs of the body contained an individual ferment which controlled and directed the function of that organ, particularly the assimilation of foodstuff into the tissue of the body. This view led him to study the particular action of the various organs and to the recognition of the role of acid in the digestive process of the stomach.

To Van Helmont, diseases were caused by the invasion of the body by foreign ferments which interfered with the controlling action of the ferments of particular organs. Thus diseases had to be studied and treated as individual specific complaints with their own individual and specific cures. Although the Helmontian view of nature did not claim many adherents in the second half of the 17th century, his works were widely read and appreciated as a source of novel ideas and experiments.

Further Reading

• Van Helmont's chemical work is treated in some detail in J. R. Partington, A History of Chemistry, vol. 2 (1961). Walter Pagel, The Religious and Philosophical Aspects of Van Helmont's Science and Medicine (1944), offers a more penetrating but difficult analysis.
• Pagel, Walter, From Paracelsus to Van Helmont: studies in Renaissance medicine and science, London: Variorum Reprints, 1986.
• Pagel, Walter, Joan Baptista van Helmont: reformer of science and medicine, Cambridge Cambridgeshire; New York: Cambridge University Press, 1982.