The term “iatro-chemistry” denotes a particular phase in the history
of medicine and of chemistry. The iatro-chemists were a school of
physicians who sought to apply chemical principles to the elucidation
of vital phenomena. According to them, human illnesses result from
abnormal chemical processes within the body, and these could only be
counteracted by appropriate chemical remedies. Although this idea did
not originate with him, the chief exponent of this school is commonly
said to be Paracelsus.

A man of violent passions, coarse, drunken, arrogant, and unscrupulous,
=Philippus Aureolus Theophrastus Paracelsus Bombastus von Hohenheim=—to
give him his full name—would seem to have possessed none of the
attributes needed by the successful leader of an intellectual

Born at Etzel in Switzerland in 1493, son of a physician, William
Bombast von Hohenheim, who combined the practice of astrology with
that of alchemy, Paracelsus, even as a youth, became a wanderer,
passing from province to province and cloister to cloister, living
by telling fortunes and practising sometimes as a quack and at other
times as an army surgeon, and gaining, as he tells us, much curious
information from old women, gipsies, conjurers, and chemists. If we may
trust his own account of himself, he had, before he was thirty-three,
wandered over the whole of Europe, and even into Africa and Asia,
everywhere performing miraculous cures and constantly getting into
trouble. In 1526 he secured the appointment of Professor of Physic in
the University of Basle, and signalised his occupancy of the chair
by a course of lectures—a farrago of confused German and barbarous
Latin—in which he assailed with extraordinary vigour and unexampled
coarseness the medical system of the school of Galen. Scandalised as
his professional brethren might be, Paracelsus expressed, intentionally
or unintentionally, the feeling of impatience with which the laity
viewed a system of therapeutics based only on tradition. In this revolt
against authority he initiated a movement which, whatever might have
been its influence on medicine, served eventually, under the guidance
of worthier men, to emancipate chemistry from the thraldom of alchemy.

Paracelsus did little more than initiate. Although his many tracts
show that he was familiar with nearly every chemical preparation of
his time, many of which he used in his practice, he added no new
substance to science. A man of great ability and extraordinary talent,
he squandered his powers in dissipation. His intemperate conduct soon
lost him his chair at Basle; and, after an ignoble quarrel with the
magistracy, he fled the town, and, resuming his wandering life, died,
under wretched circumstances, at Salzburg, in his forty-eighth year.

Space will not permit of any account of the philosophical opinions
of Paracelsus—of his mysticism, his theosophy, his pantheism, his
extraordinary doctrine of the Archæus and Tartarus, his association of
astrology with medicine. His chief merit lies in his insistence that
the true function of chemistry was not to make gold artificially, but
to prepare medicines and substances useful to the arts. He thereby made
chemistry indispensable to medicine, and thenceforward chemistry began
to be taught in the universities and in the schools as an essential
part of a medical education.

Paracelsus is usually regarded as a typical alchemist—the kind of
man made familiar to us by the paintings of Teniers, Van Ostade, and
Stein—a boorish, maudlin knave, who divided his time between the
pothouse and the kitchen in which he prepared his extracts, simples,
tinctures, and the other nostrums which he palmed off upon a credulous
world, as ignorant and superstitious as himself. There is much in the
personal history of Paracelsus that serves to justify such a view of
him. That he was in the main an impudent charlatan, ignorant, vain, and
pretentious, there can be little doubt. He had an astonishing audacity
and a boundless effrontery; and it was largely by the exercise of these
qualities that he secured such professional success as he enjoyed.

To judge from the number of the published works associated with his
name, he was an active and industrious writer. Considering that during
the greater part of his waking time he was more or less intoxicated, it
is difficult to conceive what opportunity he had for composing them.
Only one or two are known to be genuine. These, according to Operinus,
his publisher, he dictated; and from their incoherence and obscurity,
their mystical jargon, and misuse of terms, they read like the ravings
of one whom drunkenness had deprived of reason. Many of the tracts and
larger works appeared after his death—some of them years after; and
there is no certain proof that he was the actual author. Even if we
regard them as suppositious, the fact that they should be published
under his name is significant of the influence and notoriety which this
extraordinary man succeeded in achieving during his short and chequered

The immediate followers of Paracelsus—among whom may be named
Thurneysser, Dorn, Severinus, Duchesne—distinguished themselves only
by the boldness with which they promulgated his doctrines, and the
unscrupulous use which they made of his methods. They were all zealous
anti-Galenists, who professed to believe that the sum and perfection
of human knowledge was to be found in the Cabala, and that the secrets
of magical medicine were contained in the Apocalypse. They adopted
pantheism in all its grossness: everything that exists eats, drinks,
and voids excrement; even minerals and liquids assimilate food, and
eliminate what they do not incorporate. Sylphs inhabit the air, nymphs
the water, pigmies the earth, and salamanders the fire. Thus even the
Aristotelian elements were animated. Mercury, sulphur, and salt were,
according to Paracelsus, the primal principles which entered into
the composition of all things, material and immaterial, visible and
invisible. The following so-called “harmonies” were essential articles
of faith with a Paracelsian:—

Soul Spirit Body
Mercury Sulphur Salt
Water Air Earth

The laws of the Cabala were held to explain the functions of the body.
The sun rules the heart, the moon the brain, Jupiter the liver, Saturn
the spleen, Mercury the lungs, Mars the bile, Venus the kidneys.
Gold was a specific against diseases of the heart; the liquor of Luna
(solution of silver) cures diseases of the brain. “The remedies,” said
Paracelsus, “are subjected to the will of the stars, and directed by
them. You ought, therefore, to wait until heaven is favourable before
ordering a medicine.”

The Paracelsian physicians, for the most part, were a set of dangerous
fanatics, who, in their contempt for the principles of Hippocrates,
Galen, and Avicenna, and in their reckless use of powerful remedies,
many of them metallic poisons, wrought untold misery and mischief. The
inevitable reaction set in, and certain of the faculties, particularly
that of Paris, prohibited their licentiates, under severe penalties,
from using chemical remedies. It is not to be supposed, however, that
all iatro-chemists were unscrupulous charlatans. Some of them clearly
perceived the significance and true value of the movement which
Paracelsus may be credited with having originated.

=Andreas Libavius=, or Libau, originally a physician, born in Halle,
is best known by his _Alchymia_, published in 1595, which contains an
account of the main chemical facts known in his time, and is written
in clear and intelligible language, in strong contrast to the mystery
and obscurity of his predecessors. He was the discoverer of stannic
chloride, still known as the fuming liquor of Libavius, and described
a method of preparing oil of vitriol in principle identical with that
now made use of on a manufacturing scale. He died in 1616.

=John Baptist van Helmont=, a scion of a noble Brabant family, was
born in Brussels in 1577. After studying philosophy and theology at
the University of Louvain, he directed his attention to medicine, and
made himself familiar, in turn, with every system from Hippocrates to
Paracelsus. Having spent some time in travel, he settled on his estate
at Vilvorde, and occupied himself with laboratory pursuits until his
death in 1644.

Van Helmont was a scholarly, studious man, and a philosopher. A
theosophist and prone to mysticism, he had many of the mental
characteristics of Paracelsus, without his fanaticism and overweening
egotism. He narrowed the number of Aristotle’s elements down to one,
and, like Thales, considered water to be the true principle of all
things, supporting his theory by ingenious observations on the growth
of plants (see p. 20). He first employed the term _gas_, and was aware
of the existence of various æriform substances, anticipating Hales, who
has been styled the father of pneumatic chemistry, in the discovery of
many gaseous phenomena. He gave an accurate description of carbonic
acid gas, which he termed _gas sylvestre_, and showed that it is
produced from limestone and potashes in the fermentation of wine and
beer, and that it is formed in the body and in the earth. The doctrines
of the iatro-chemists were further spread by Sylvius in Holland, and by
Willis in England.

=Francis de le Boë Sylvius=, born at Hanau in 1614, became Professor
of Medicine in the University of Leyden, where he exercised great
influence as a teacher until his death in 1672. Medicine he treated
simply as a branch of applied chemistry, and the vital processes of
the animal body as purely chemical. He freed the theory of physic from
much of the mystical absurdity introduced into it by Paracelsus and
van Helmont, and by his practice brought chemical remedies once more
into vogue. He was aware of the distinction between venous and arterial
blood, and that the red colour of the latter was due to the influence
of air. Combustion and respiration he regarded as analogous phenomena.

=Thomas Willis= was born in Wiltshire in 1621, and while a student at
Christchurch bore arms in the Royalist army when Oxford was garrisoned
for Charles I. In 1660 he became Sedleian Professor of Natural
Philosophy, and ultimately settled in London as a physician. He died in
1675, and was buried in Westminster Abbey.

Willis imagined that all vital actions were due to different kinds of
fermentation, and that diseases were caused by abnormalities in the
fermentative process. Although a Paracelsian as regards his theory of
the constitution of matter, he followed Sylvius and his pupil Tachenius
in banishing mysticism from medicine. He was a skilful anatomist, and
gave the first accurate description of the brain and nerves.

Other notable iatro-chemists were Angelus Sala, Daniel Sennert, Turquet
de Mayerne (who became body physician to James I.), Oswald Croll,
Adrian van Mynsicht, and Thomas Lieber. Croll introduced the use of
potassium sulphate and succinic acid into medicine, and Van Mynsicht
that of tartar emetic. Various antimonial preparations had previously
been employed by chemical physicians since the time of Basil Valentine,
despite the ban of the Parliament of Paris on their use.

The chief service of iatro-chemistry to science consisted in its
influence in bringing chemistry within the range of professional study,
whereby a great extension in its pursuit was effected, with the result
that a largely increased number of substances was discovered. Moreover,
this wider experience of chemical processes familiarised workers with
chemical phenomena in general, and thereby contributed to lay the
foundations of a general theory of chemical action, which a succeeding
age strove to complete.

During the period of iatro-chemistry, which may be said to have
extended from the first quarter of the sixteenth century to the latter
half of the seventeenth, chemistry was advanced along practical
lines by the labours of many men, chief of whom were Agricola the
metallurgist, Palissy the potter, and Glauber the technologist. These
men were primarily experimental chemists, who took little or no part
in the fruitless polemics of the period, but followed their avocation
in the true spirit of investigators, and thereby enriched science with
many new and well-ascertained facts.

=George Agricola=, born at Glauchau in Saxony in 1494, was a
contemporary of Paracelsus. After studying medicine at Leipzig, he
devoted himself to metallurgy and mineralogy, first at Joachimsthal,
and published a number of works which were long deservedly regarded as
the leading treatises on these subjects.

In his _Libri_ XII. _de re Metallica_ he gives an account of what was
known in his time respecting the extraction, preparation, and testing
of ores. He describes the smelting of copper and the recovery of the
silver which might be associated with it. He also describes methods of
obtaining quicksilver, and of purifying it by treatment with salt and
vinegar. He gives a full description of the method of obtaining gold by
amalgamation, and of recovering the mercury by distillation. He gives
accounts of the smelting of lead, tin, iron, bismuth, and antimony,
and describes the manufacture of salt, nitre, alum, and green vitriol.

The whole work, which is of folio size, is illustrated by wood-cuts,
which give a faithful idea of the nature of the several operations, and
of the character of furnaces, trompes, bellows, and tools employed in
them. It is by far the most important technical work of the sixteenth
century, and it exercised great influence on the art of metallurgy.
The descriptions—at least as regards European processes—are evidently
the result of personal observation. Agricola visited the mines, and
faithfully noted the different methods of sorting and washing the
ores, the characters of which he accurately describes. His accounts
of the various smelting operations are so detailed that it is obvious
they must have been put together after personal inquiry. The study of
metallurgy, indeed, was the main object of his life; and he devoted to
its pursuit even the pension which had been settled on him by Maurice,
Elector of Saxony. He became Mayor of Chemnitz, died there in 1555, and
was buried at Zeitz.

=Bernard Palissy= lived throughout the greater portion of the sixteenth
century. Although not a professed chemist, nor a follower of any
particular school, he was an ardent self-taught experimentalist and a
keen and accurate observer, who greatly enriched ceramic art by his

=Johann Rudolf Glauber= was born at Karlstadt, in Bavaria, in 1604,
and after a restless life died in Amsterdam in his sixty-fourth year.
He published an encyclopædia of chemical processes, in which he
describes the preparation of a great variety of substances of technical
importance. The greater number of the pharmacopœias of the seventeenth
century are indebted to him for their descriptions of the mode of
manufacture of their official preparations. He discovered sodium
sulphate—his _sal mirabile_, still frequently named after him—and
introduced it into medicine.

During this period the common mineral acids—sulphuric, hydrochloric,
and nitric—became ordinary articles of commerce, and were used in the
manufacture of a number of useful products, chiefly inorganic salts.
A considerable number of metallic oxides were also in common use, and
were applied to a variety of purposes in the arts. The knowledge of
definite organic substances was much more limited. Acetic acid had long
been known, but was first obtained in a concentrated form during this
period by the distillation of verdigris. A number of other acetates
were also known, as well as certain tartrates—as, for example, salt of
sorrel, Rochelle or seignette salt, and tartar emetic. Succinic and
benzoic acid were introduced into medicine, and Tachenius discovered
one of the characteristic acids of fat and oil (stearic acid). Spirit
of wine was, of course, largely made and used in the preparation of
tinctures and essences. Ether, originally known as _oleum vitrioli
dulce verum_, was first discovered by Valerius Cordus; and a mixture of
it with alcohol, long known as Hoffmann’s drops, appears to have been
employed as a medicine by Paracelsus.