HELMONT, JAN BAPTISTA VAN, Lord of ,,erode, Royenborch, Oorschot, and Pel lines, an eminent Belgian chemist, was b. at Brussels iu 1577, and d. near Vilvorde in 1674. He went through the regular course of study at the university of Louvain, and on the completion of his education, he was offered and accepted the chair of sur gery in that university, the duties of which he discharged for two years. The study of the works of Paracelsus seems to have turned his special attention-to chemistry and natural philosophy, and in the pursuit of these sciences he spent several years in the different universities of Italy and France; after which lie returned home, married Mar garet van Ranst, a noble lady of Brabant, and settled down at his estate near Vilvorde, where he spent the remainder of his life in philosophic investigations of various kinds. It would be impossible, in the limits of this article, to sketch even an outline of his chemical discoveries. Writers of the history of chemistry regard him as the greatest chemist who preceded Lavoisier; and it is much to be regretted that his language is H often so obscure, that it is not always easy to ascertain his meaning. lie was the first to point out the imperative necessity for employing the balance in chemistry. Ile paid much attention to the study of the gases, and is supposed by some authorities to have been the first to apply the term gases to elastic aeriform fluids. Of these gases lie dis tin,,ouished several kinds. He was also the first to take the melting-point of ice and the boiling-point of water as standards for the measurement of temperature. By means of
the balance he showed, in many instances, the indestructibility of matter among chemi cal changes. For example, he demonstrated that a salt dissolved in water, or silver dissolved in aquafortis, could be recovered unchanmed in quantity. It is in his works that the term saturation is first employed, to signify the combination of an acid with a base; and lie was one of the earliest investigators of the chemistry of the fluids of the human body.
Alonrr with other physiologists of his day, he speculated much on the seat of the soul, which lie placed in the stomach. His reasons are chiefly these two: 1. It cannot exist in the brain, because that organ contains (according to hehnont) no blood; 2. It does exist in the stomach, because when we hear bad news, we lose our appetite. Those who wish to know the full value of his contributions to the knowledge of chemistry, may consult the histories of Chemistry written by Kopp and Hofer.
The most important of his works is his Ortus Medk irtee, id est initia Physics inaudita, progressus Medicine novus in nwrborum ultionem ad Titan] longam, which was published by his son four years after his death, passed through a very large number of editions, and was translated into Dutch. French, German, and English. A very curious volume, containing translations of some of his works, was also published by W. Charlton, in 1650, under the title of The Ternary of Paradoxes; the Magnetic Cure of Wounds; the .Meticity of Tartar in Wine; and the Image of God in Man.