Furnaces for philosophers

Colin Russell tells the story of an early industrial chemist Johann Glauber.

Four hundred years ago a man was born who became arguably the greatest practical chemist of the 17th century and possibly the world’s first industrial chemist. Johann Rudolph Glauber was born in 1604, the son of a barber in the Bavarian town of Karlstadt, Germany. 

Without university training or even an apprenticeship with an apothecary he became a self-educated chemist, picking up vast amounts of information from reading, conversation and experiment. He never regretted a lack of book-learning: ’neither doth it ever repent me that I have out my hands to the Coals, and have by the help of them penetrated into the knowledge of the secrets of Nature’. That would have rung many bells with England’s empiricist Baconians, with Francis Bacon advocating experimentation to prove hypotheses.

If alive today, Glauber would infuriate editors and publishers by his rambling prose, verbosity and frequent obscurity. His almost endless stream of books described his work and praised his products to an extent that would make a modern manufacturer blush. Today’s safety officials would be more offended, with many of his experiments deemed dangerous even in his day: mineral acids were flung on solids with cheerful abandon, and all manner of curious substances fused with a favourite compound of his, saltpetre or nitre (KNO ₃).

When Glauber was 14, Europe was plunged into a conflict that devastated the German lands and lasted until 1648. The Thirty years war involved the rise of nationalism, increasing poverty for a growing population, religious conflicts and power struggles in the so-called Holy Roman empire. Among the few German chemists there was a brain drain to less troubled areas, with, for example, Becher going to Vienna, Austria, and Kunckel to Sweden.

Glauber himself began to travel and, at the age of 21, found himself in Vienna where he contracted some severe gastro-intestinal ailment known as ’the Hungarian disease’. Unable to take any solid food he was recommended to try drinking water from a spring near Neustadt. Improvising a cup by hollowing out part of a loaf he imbibed some of the fluid and was cured with astonishing rapidity. It is even said that relief was so quick that he immediately ate the rest of his loaf. Naturally he wanted to know why this had happened. So he evaporated some of the water and obtained long crystals like those of nitre (which is doubtless why the local name for it was Salpeter-Wasser). Glauber showed that this was incorrect and called it sal mirabile, or miraculous salt. He later showed that this was the same compound as that obtained when vitriol (sulfuric acid) acted on common salt. Sodium sulfate is a powerful purgative and was used as such until quite recently, known to ordinary folk as ’Glauber’s salt’.

This strange incident, which gave Glauber’s name a permanent place in common language, may also have been a starting point for his study of chemistry. This was the age of chemical medicine, inspired by the strange teachings of Paracelsus. Much of Glauber’s work was devoted to a search for powerful nostrums, though he did not quite attain the alchemical goal of a universal medicine that would banish all disease and confer immortality. He found a supposed ’medical’ use for most of his laboratory products, and was especially keen on mineral substances such as antimony (v) sulfide. He also believed in the ’alkahest’ suggested by the Flemish alchemist van Helmont, a solvent that could dissolve everything (though what he might have kept it in would have posed quite a problem). He did claim to have discovered how to prepare this mystical substance, but declined to publish his secret lest he ’encourage the luxury, pride and godlessness of poor humanity’.

At this time there was no satisfactory theoretical basis for chemistry. Glauber inclined to the doctrine of Paracelsus that there were three ’principles’ in which the four `elements’ manifested themselves in matter: salt, sulfur and mercury. His own obsession with salts of various kinds seems to reflect this view. But at the same time traditional alchemy flourished, with its belief in the possibility of transmutation of metals. Glauber thought this was confirmed by the action of iron on solutions of copper salts, regarding the displaced copper as a transmutation product of the iron. On that basis it should be quite possible to turn silver into gold. With all these alchemical and Paracelsian ideas filling his head Glauber embarked on a career in chemistry and became (in the eyes of some historians) the world’s first industrial chemist. Among his other objectives there seems to have been a desire to bring material benefit to the German lands that were beginning to suffer badly from the war.

By the late 1630s conditions in the German lands were already bad but were soon to get markedly worse. As the conflict intensified multitudes were killed. By the end of the Thirty years war at least one third of central Europe’s population is reckoned to have died as a direct consequence of that war. And in the 1630s horror was piled upon horror as first the Swedes and then the French ravaged Glauber’s native Bavaria. He moved to Giessen to become a court apothecary, and there married a girl from whom he was quickly divorced due to her infidelity. A second marriage was more lasting and eight children were born.

Even Giessen eventually became unsafe and, in 1639, Glauber left Germany to settle in Amsterdam, then a great industrial centre. He remained in the Netherlands, with one or two short absences abroad, until the end of the war when he returned to Germany, settling in Kissingen. Here were mineral springs (to furnish materials for his laboratory work) and vineyards (where work would be a cover for his secretive alchemical activities).

Following some bitter personal feuding in Germany he returned to Amsterdam in 1655. A magnificent laboratory was established and experiments and writing continued until his health began to fail in the 1660s. Despite all his success he died in poverty in 1670.

Salts in general were a great preoccupation for Glauber, though he did not of course view them as we should. From common salt and vitriol he obtained in 1651 not only sodium sulfate but also ’aqua fortis’, or hydrochloric acid. He was not the first to do this but he did produce it in large quantities. He tried its action on many metals, often noting the evolution of ’airs’ in the process; unfortunately at that stage in chemical history there was no means of collecting them. He proclaimed the medicinal virtues of the products which aqua fortis yielded with minerals, and seems to have discovered ethyl chloride from its action on wines. The sulfuric acid needed to make hydrogen chloride was prepared by the known methods of heating hydrated mineral sulfates (as alum) or sulfur combustion.

However, the mineral salt that fascinated Glauber most of all must surely have been nitre. By treating it with vitriol he obtained ’acid spirit of nitre’, or nitric acid, the first person to do so. This also dissolved many metals including silver, could etch copper plates, and gave a yellow colour to organic materials. Nitre itself could be heated with charcoal and the product leached out to give ’liquor of fixed nitre’, in other words potash. Nitre could be reconstituted by mixing the two solutions. He heated it with arsenic (iii) oxide and obtained a blue liquid, destroyed by water; this must have been N ₂O ₃. Even more remarkable was the fusion of nitre with manganese (ii) oxide when the unmistakeable purple colouration of KMnO ₄ was obtained. Many other spectacular reactions of nitre were observed, and it was probably its reaction with ammonia that yielded Glauber his ’most secret sal ammoniac’, an important goal for an alchemist as it was allegedly carried by Adam from the Garden of Eden; presumably it was ammonium nitrate. At a much more mundane level Glauber recommended nitre as a fertiliser.

Glauber discovered other new substances such as arsenic (iii) chloride and potassium acetate, and was the first to distil coal (1648) and possibly wood. He examined the coal-tar distillates and advocated wood-tar as a means of protecting fruit from insect attack and wood from rotting. On distilling wood-tar he obtained pyroligneous acid and acetone. He treated many plant materials with mineral acids and obtained precipitates when the solutions were treated with alkalis; who knows what alkaloids he innocently obtained this way?

His studies led him to approach the concept of affinity (Gemeinschaft), recognising something like an order of displacement of metals and writing of silica and potash that ’they love each other very much’. Similar romantic feelings were attributed to zinc oxide which ’loves acids very much and is loved by them’.

In all this work Glauber was able to use furnaces that he had devised, some having chimneys for the first time so enabling better draughting of the fire and thus higher temperatures. These were described in an immensely important book, though with a name curious to our ears: New philosophical furnaces. First appearing in 1646, it went through many editions and translations, describing not merely furnaces but much other apparatus that he had devised. One technique that he greatly improved was sublimation. It has been said that this was the first comprehensive textbook ever to appear on industrial chemistry, apart only from those earlier volumes by the geologist Agricola and others on metallurgy. It was one of about 30 books he wrote, mainly while in Amsterdam.

In all his experiments Glauber had a constant eye on possible applications for his products. Many of these did not work and he acquired something of a reputation as a charlatan. Thinking one of his products might be a hair-restorer he applied it to his own bald head which ’began to be covered with black curled hairs, from which I am verily persuaded that had I more of this Tincture, it would have wholly renewed me.’ It is probably as well that he had no more. His own health must have suffered considerably from such personal experiments as well as from his constant exposure to materials containing mercury, arsenic, antimony and lead.

Glauber was also interested in coloured glass manufacture, particularly the ruby glass containing gold and a blue glass containing cobalt. He discovered a precursor of the borax bead test when (in this case) fusible glass gave specific colours with a wide range of metals. He showed how to make linen threads lustrous by boiling alkalis and garments waterproof by treatment with linseed oil and lead oxide. Perhaps his most bizarre invention related to a primitive form of chemical warfare: he advocated spraying or bombing the ’Turks’ with concentrated mineral acids, hardly a weapon of mass destruction but at short range a lethal one nevertheless. His ’Turks’ were presumably the invading armies of hostile Europeans in the Thirty years war.

We conclude with remarks from two contemporaries. The first from a chemist who was very familiar with Glauber’s work and indebted to it, the other from a politician who owned one of Glauber’s books.

The first author writes: ’I could not borrow of Glauber the various Phenomena I have particularly set down’ (which in fact shows how well aware he was of Glauber’s work), and elsewhere he remarked that Glauber’s furnaces became the first of his ’better ways of doing many things in Chymistry [sic]’. The second writer put a hand-written inscription in one of Glauber’s books: ’This Glauber is an errant knave. I do bethink me he speaketh of wonders which cannot be accomplished’. In these two statements lies a summary of Glauber’s work: enormously influential on one hand, and highly contentious on the other. The name of the first writer was Robert Boyle; the second was Oliver Cromwell. Perhaps it takes a chemist, not a politician, really to appreciate another chemist.

Acknowledgements

Colin Russell is emeritus professor in the department of history of science at the Open University and affiliated research scholar at the department of history and philosophy of science, University of Cambridge

Further Reading

K Ahonen, Dictionary of Scientific Biography, article on ’Glauber’.

J R Partington, A History of Chemistry, vol. ii, Macmillan, 1961.