Iatrochemistry

It was in the great school of Alexandria that these separate paths came together and eventually led to the alchemy and iatrochemistry of future generations and, eventually, the chemistry of modern science. 

Debus, Allen George. Alchemy and iatrochemistry persistent traditions in the 17th and 18th centuries. Quimica Nova [SociedadBrasileira de Quimica] 15 (1992) 262-268. 

Keezer, W.S. Historical and philosophical aspects of iatrochemistry and iatromechanics. II. Paracelsus alchemical mystic. TexMed60 (Dec 1964) 1008-1012. 

Debus, Allen George. "Iatrochemistry and the Chemical Revolution." In Alchemy revisited, ed. Z.R.W.M. von Martels, 51-66. Leiden Brill, 1990. 

Debus, Allen George. "Chemistry and iatrochemistry in early eighteenth-century Portugal a Spanish connection." In Historia e Desenvolvimento da Ciencia em Portugal I Coloquio ate ao SecoloXX. Lisboa, 15 a 19 Abril de 1985, ii, 1245-1262. Lisboa , ... 

This distinction between "theoretical" and "practical" chemistry was one observed in textbooks throughout the eighteenth and nineteenth centuries. A tradition of "philosophical chemistry" answered Libavius s challenge for chemistry to abandon alchemical magic and Paracelsian iatrochemistry in favor of newly philosophic principles in chemistry. Jacob Bamer s seventeenth-century work, Chymiaphilosophica, is an early example later, more famous texts in chemical philosophy are those of John Dalton (1808), Davy (1812), and Dumas (1837). 14 But texts called chemical philosophy were fewer than those in "natural philosophy," and very few texts in chemical philosophy were written after 1840.15 Why was this the case ... 

For over 2,000 years, alchemy was the only chemistry studied. Alchemy was the predecessor of modern chemistry and contributed to the slow growth of what we know about the Earth s chemical elements. For example, the alchemists interest in a common treatment for all diseases led to the scientific basis for the art of modern medicine. In particular, the alchemist/ physician Paracelsus (1493-1541) introduced a new era of medicine known as iatrochemistry, which is chemistry applied to medicine. In addition, alchemists elementary understanding of how different substances react with each other led to the concepts of atoms and their interactions to form compounds. 

A typical alchemical treatise (this one from the early eighteenth century, but a revised version of a work from 1698) by a Dutch pharmacist and physician notes that iatrochemistry (medical alchemy) is divided into theory and praxis. The author acknowledges that Theory holds a higher place in his own writing. Yet Theory alone is useless unless married with Praxis. 

The term valence, of which ambivalence is not merely a variation, but a decidedly new and separate concept, derives from chemistry and atomic physics. Valence can refer to an extract or tincture, usually from an herb. In this connotation, it has obvious ties with the field of medical alchemy, or iatrochemistry. In the mid-i8oos, valence theory began to be used to signify the normal number of bonds that a given atom can form with other atoms—a register that links valence with philosophical materialism, matter, and Epicurianism. In recent scientific work, valence refers specifically to the number of electrons in the outermost shell of atoms. It is not provisional or occasional in its relation to the atom. Valence is atomicity. It defines a given chemical element, perhaps not in its essence, but in its capacity to combine with other elements—its potentiality. Valence is denoted by a simple number, and elements are said to be monovalent, bivalent, trivalent, quadrivalent, and so on. About one-fifth of all elements have a fixed valence (sodium is always i, or monovalent calcium is always 2, or bivalent and so on). Many elements have valences that are variable, depending on the other elements with which they are combined. 

Boyle was a firm believer in iatrochemistry, the preparation of drugs by chemical means ( iatro means medicine or healing). He devoted a great deal of time to trying to develop new medicines and to collecting medicinal recipes from every source he could find. He... 

Two additional material principles were added to the tria prima in the seventeenth century to form the five-principle view that characterized the iatrochemistry until the middle of the eighteenth century, when the four Aristotelian elements returned largely through the influence of the French chemist Pierre-Joseph Macquer. Robert P. Multhauf has given a splendid account of these pre-modern years in The Origins of Chemistry. ... 

From a general historical perspective we can characterize Paracelsus and iatrochemistry as a kind of counter-culture of the sixteenth century, a revolt against the rigidity of the University curriculum and its isolation from experience. Similar movements can be found in religion, politics, the arts, and economics, the whole period being characterized by changes and upheaval that we call the Renaissance. 

Lemerys Cours de chymie remained the standard text in France for more than three quarters of a century, providing the major continuity that connects iatrochemistry with the so-called chemical revolution. 

Europe, thought that chemistry was part of medicine, or even that medicine was part of chemistry. That was the program of the medical chemists, or ia-trochemists, who followed the lead first offered by Paracelsus and then modified and extended by Van Helmont. They carried on with their chemistry or iatrochemistry through the seventeenth and into the eighteenth century, and they took precious little account of what mechanists were doing. 

Lemery s chemistry in essence went back to the iatrochemistry of Sylvius. He defined the active principles, i.e. salts, sulphurs and spirits, according to the figure and shape of their particles. Moreover he divided the salts into acids and alkalis. Acids consist of pointed particles set in motion. Alkalis have porous parts so that the acid points can enter the composition and divide whatever opposes their motion. As a result of the acids breaking the resistance of the alkalis a violent ebulhtion occurs. This means that they can indicate each other s presence when combined together. Gradually Lemery s theory was widely accepted and it was beheved that all substances, even the metals, were composed of acids and alkahs. 

Greco-Arabic classics, insisted on the value of experimentation (including the use of animal tests), and developed the idea that minerals and chemicals could have medicinal applications (iatrochemistry). His use of mercury preparations in the treatment of syphilis led to accusations of poisoning, to which Paracelsus replied by writing the Third Defense. It contains the following important statement ... 

In terms of the theory of elements, Paracelsus s contribution was not his work, although he did write about how the three principles made up most of terrestrial matter, but his role in the redirection of alchemy. He de-emphasized the concept of transmutation (although it is likely he believed it possible) and focused on practical aspects of the study of matter, particularly iatrochemistry. He also encouraged the investigation of materials through experiments. While this should not be confused with modern experimentalism, since Paracelsus included spiritualism and occult theory in his system of investigation, it was far more systematic than most alchemy tended to be. He also based his work on a conception of pure compounds, and that concept, in turn, led to work on purification and qualitative control of chemical research and production. 

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