of oppression that was famously suffered by Galileo, who had the misfortune to support the idea in less tolerant times. But Galileo’s ‘martyrdom’ was of a relatively mild sort. Giordano Bruno, another heliocentric rebel, was burnt at the stake in 1600 – not, however, for his scientific views but because of his religious heresies. House arrest, to which Galileo was condemned, might seem trivial in comparison; but there was always the threat that it might turn into something worse.
That was largely why the works of Jan Baptista van Helmont (1579–1644) went unpublished in his lifetime. Confined to Vilvoorde in the duchy of Brabant by order of the Inquisition, he did not want any more trouble with the Church. Van Helmont (Figure 1) was no rebel-rouser – in fact he chose to pursue a remarkably quiet, undemonstrative life, turning down offers for appointment as court physician from several princes. Yet this reticence belied an ambition to fashion a chemical philosophy of startling scope – the last, in fact, of its kind – and, when challenged, he did not mince his words.
Van Helmont studied at the University of Louvain, but he felt that academic qualifications were mere vanities and he turned down the degree he had earned. Despite this independence of mind, he was at first something of a medical traditionalist; it was only after he was cured of an itch by an ointment derived from the chemical medicine of the Swiss iconoclast Paracelsus that he converted to this new kind of ‘physick’. Whereas traditional medicine throughout the Renaissance was based on the ideas of the Greek doctor Hippocrates and the Roman Galen, which held that health was governed by four bodily fluids called humours, Paracelsus (1493–1541) maintained that specific diseases should be treated with specific remedies created from nature’s pharmacopoeia by the art of alchemy. Several decades after his death, Paracelsus’s ideas gained popularity throughout Europe, and by the early seventeenth century the medical community was divided into Galenists and Paracelsians.
Van Helmont studied the writings of Paracelsus and found much there that seemed to him to be sound advice. But he was by no means an uncritical disciple. Paracelsus tended to surround his chemical medicine with a fog of obscure terminology and overblown notions of how the world worked. Humankind, he said, was a microcosm reflected in the macrocosm of the universe, so that the disorders of the body could be compared to the disorders of nature – epilepsy, for example, known as the falling sickness, was akin to the tremors that shook the ground in an earthquake. This concept of a correspondence between the microcosm and the macrocosm was a central theme in Neoplatonic philosophy and was popular with the Jabirian alchemists. But to van Helmont it looked like sheer mysticism, and he would have none of it.
Figure 1 Flemish physician and alchemist Jan Baptista van Helmont
(Reproduced Courtesy of the Library and Information Centre, Royal Society of Chemistry)
Instead, he pursued the difficult task of separating what was worthy in the works of Paracelsus from what was nonsense: he wanted the chemical medicine without the chemical philosophy. But that did not mean he was free of mysticism himself, for like Paracelsus he felt it was essential that chemical science be based in Christian theology. In his own mind he was replacing speculation with rigorous theory; but from today’s perspective there is often not a great deal to differentiate the philosophy of Paracelsus from that of van Helmont.
For example, van Helmont supported the Paracelsian cure known as the weapon salve, an idea that seems now to be ridiculously magical. To cure a wound made by a weapon, you should prepare an ointment and then apply it not to the cut but to the blade that made it. However unlikely a remedy, van Helmont was convinced that it had a perfectly rational, mechanistic explanation. The natural magic of the Neoplatonists was not mere superstition; it was based on the belief that the world was filled with occult forces, of which magnetism was an incontestable example. The weapon salve mustered these forces to allow the vital spirits of the blood on the blade to reunite with that in the body.
When van Helmont published a defence of the weapon salve in 1621, it was criticized by a prominent Jesuit. Van Helmont responded by explaining the ‘mechanism’ of the cure, and he rather unwisely compared it to the way religious relics produce ‘healing at a distance’. The University of Louvain found this a scandalous thing to suggest, and van Helmont’s ideas were brought before the Spanish Inquisition (Spain ruled the Low Countries at that time). He was declared a heretic, and was lucky to escape with nothing more severe than a spell in prison before being freed through the intervention of influential friends. Thereafter, van Helmont was forbidden to publish anything further without the approval of the Church, or to leave his home without the permission of the Archbishop of Malines – a restriction that applied even in times of plague. During one outbreak, his family refused to leave the town without him, and two of his sons succumbed to the disease.
So his writings on chemistry and medicine were not published until after his death, when his son Franciscus Mercurius inherited his manuscripts. Van Helmont’s collected works appeared in Latin under the title Ortus Medicinae (Origins of Medicine) in 1648, which John Chandler translated into English in 1662 as Oriatrike; or, Physick Refined.
Ortus Medicinae contains a wealth of striking ideas, most notably the suggestion that digestion (which Paracelsus saw as an alchemical process conducted by an ‘inner alchemist’ called the Archeus) is a kind of fermentation involving an acid. The book is a curious mixture of new and old, prescient and regressive. Just as the mechanistic philosophy of Descartes and his followers was taking hold in Europe (and shortly before it was to be refined in Isaac Newton’s Principia Mathematica), van Helmont challenged the Cartesian division of body and soul by arguing for a kind of vital force that animated all matter. Van Helmont believed that he would find this ‘world spirit’, the spiritus mundi, by distilling blood.
At the same time, he called for an end to the sort of science that relied solely on logical thinking and mathematical abstraction – it should instead be based on observation, on experiment. As a demonstration of what could be gained that way, van Helmont explained how he had come to understand that everything was made from water.
Well, not quite everything. The other of the Aristotelian elements that he continued to countenance was air. But this air, he said, is inert and unchanging, and so all else is nothing but water. ‘All earth, clay, and every body that may be touched, is truly and materially the offspring of water onely, and is reduced again into water by nature and art.’
In support of this claim, van Helmont explained how ‘I have learned by this handicraft-operation, that all Vegetables do immediately and materially proceed out of the Element of water onely.’ Whether or not he knew of the experiment proposed by Nicholas de Cusa, he had actually gone ahead and done it.
It required the kind of patience that perhaps house arrest cultivates in a person. Van Helmont took 200 pounds of earth, which he dried in a furnace and then moistened with rain water. He placed it in a pot and planted within it a small willow sapling weighing five pounds. And then he waited for five years.
He watered it whenever necessary, but carefully excluded all other sources of matter. Van Helmont explains how, to keep out dust, he ‘covered the lip or mouth of the Vessel, with an Iron Plate covered with Tin’, which was ‘easily passable with many holes’ to let through water and air. In other words, like Nicholas de Cusa he was thinking about how to exclude influences that could corrupt his results.
At the end of that time he weighed the tree again, and also the soil, which was only about two ounces short of the original 200 pounds. The tree, however, had grown immensely. ‘One hundred and sixty-four pounds of Wood, Barks, and Roots arose out of water onely’, he said. And he added that he had not included in this estimate the weight of the leaves that had grown and then fallen over four autumns.
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