Mineral acids of the pseudo-Geber corpus
The earliest known recipe for nitric acid (aqua fortis): distillation of vitriol, saltpetre and alum, and, with sal ammoniac added, the gold-dissolving aqua regia. The texts were written in Latin at the end of the 13th century and signed with the name of Geber (Latinised Jabir), but in the main belong neither to the Arab Jabir nor to any single author.
These reagents gave alchemists and assayers a new means of separating metals (parting gold from silver) and of making numerous new salts. According to Newman, it was the acids that made it possible to identify 'atoms' that withstand dissolution, and so changed ideas about the composition of metals.
Authorship is disputed: Newman regards Paul of Taranto as the author of the Summa perfectionis and assigns the writings on acids to later layers of the corpus.
Why this date
approximate. The Summa perfectionis, according to Newman (1991), was written in the late 13th century, its probable author the Franciscan Paul of Taranto; Britannica and Wikipedia give about 1310. The acid recipes are not in the Summa itself but in the later works of the corpus: the earliest known recipe for nitric acid (aqua fortis) is in De inventione veritatis (Karpenko, Norris 2002); according to Newman, knowledge of the mineral acids came into circulation probably a few years after the Summa was composed. Sulfuric acid in the Summa is doubtful: the language of the passage on distilling vitriol is unclear (Karpenko, Norris 2002). The axis value is the turn of the 13th to 14th century.
What grew out of it
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Van Helmont's weight balance and the willow experiment (Ortus medicinae)
influenced · Confidence: medium
Strong acids were the working tool of Van Helmont's weight experiments: he recovered the sand from glass by analysis with acid, and demonstrated the indestructibility of matter on metals dissolved in acid and recovered in their former quantity.
Dispute: No historian derives Van Helmont's experiments directly from the pseudo-Geber acids; the quotes show only that acids were used in his weight experiments, and Newman describes the passage from the weak acids of the 13th century to the mineral acids on the example of Sennert, Van Helmont's contemporary. The willow experiment needs no acids, so the acids accompanied his work rather than being a necessary condition of it.
Link sources
- Newman W. R. «What Have We Learned from the Recent Historiography of Alchemy?», Isis 102(2) (2011)
He claimed, as a result, that the sand that went into the glass had the same weight as the sand that was released by analysis with acid.
- Pagel W. «Helmont, Johannes (Joan) Baptista van», Dictionary of Scientific Biography (via Encyclopedia.com) (1972) Verified 5 Oct 2026
On the indestructibility of matter, Helmont stated that metals dissolved in acid are not thereby destroyed or transmuted
- Newman W. R. «What Have We Learned from the Recent Historiography of Alchemy?», Isis 102(2) (2011)
Unlike Paul, however, Sennert was able to use the powerful mineral acids (nitric, sulfuric, hydrochloric, and aqua regia) to provide much more dramatic demonstrations of metallic destruction than had been possible with the weaker acids and bases available in the thirteenth century.
"Verified" means that on that day the quotation was found at the address given, word for word. No date means we have not been able to open the source yet, not that the quotation is wrong.
- Newman W. R. «What Have We Learned from the Recent Historiography of Alchemy?», Isis 102(2) (2011)
Links under review
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Distillation and laboratory apparatus
prerequisite for · Confidence: high
The claim rests on the History section of the Wikipedia article. A verbatim quotation is needed from the work it cites: Karpenko V., Norris J. A., «Vitriol in the History of Chemistry», Chemické listy 96, 2002.
The mineral acids of the pseudo-Geber corpus are obtained by distillation: the earliest recipe for nitric acid prescribes distilling a mixture of vitriol, saltpetre and alum, and without distilling apparatus such a product is physically impossible.
Dispute: Distillation is counted from Zosimos (c. 300), whereas distilling acids requires the more advanced vessels and furnaces of the Arabic-Latin tradition of the 9th to 13th centuries (the Jabirian corpus, al-Razi): the continuity runs from distillation as a method in general. Karpenko and Norris give the De inventione veritatis recipe in their own translation, and admit that their remark on a possible distillation of vitriol in the Summa itself is unclear.
Link sources
- Karpenko V., Norris J. A. «Vitriol in the History of Chemistry», Chemické listy 96(12), 997-1005 (2002), 1002
a pound of Cyprus vitriol [Fe, CuSO4], a pound and a half of saltpeter, and a quarter of a pound of alum. Submit the whole to distillation
- Karpenko V., Norris J. A. «Vitriol in the History of Chemistry», Chemické listy 96(12), 997-1005 (2002), 1002
The De inventione veritatis, in which the earliest known recipe for the preparation of nitric acid is found
- Wikipedia «Nitric acid», History (2024) Verified 20 Sep 2026
the distillation of a mixture containing niter and green vitriol, which they call eau forte (aqua fortis).
"Verified" means that on that day the quotation was found at the address given, word for word. No date means we have not been able to open the source yet, not that the quotation is wrong.
- Karpenko V., Norris J. A. «Vitriol in the History of Chemistry», Chemické listy 96(12), 997-1005 (2002), 1002
Node sources
- Karpenko V., Norris J. A. «Vitriol in the History of Chemistry», Chemické listy 96(12), 997-1005 (2002), 1002
The De inventione veritatis, in which the earliest known recipe for the preparation of nitric acid is found
- Karpenko V., Norris J. A. «Vitriol in the History of Chemistry», Chemické listy 96(12), 997-1005 (2002), 1002
a pound of Cyprus vitriol [Fe, CuSO4], a pound and a half of saltpeter, and a quarter of a pound of alum. Submit the whole to distillation
- Karpenko V., Norris J. A. «Vitriol in the History of Chemistry», Chemické listy 96(12), 997-1005 (2002), 1003
the language of this text is not entirely clear
- Newman W. R. «What Have We Learned from the Recent Historiography of Alchemy?», Isis 102(2) (2011)
This is particularly evident in the Latin corpus attributed to Geber (Jābir ibn Hayyān), which was mostly composed in and after the thirteenth century by European authors.
- Newman W. R. «What Have We Learned from the Recent Historiography of Alchemy?», Isis 102(2) (2011)
When knowledge of the newly discovered mineral acids came into circulation, probably a few years after the Summa's composition, these strikingly powerful analytical agents provided chymists with the means to identify 'atoms' that could withstand dissolution into their components.
- Newman W. R. «What Have We Learned from the Recent Historiography of Alchemy?», Isis 102(2) (2011)
One prominent example of such a debate may be found in the work of Paul of Taranto (who may also be the real author of the Summa perfectionis), whose Theorica et practica was probably composed near the beginning of the fourteenth century.
- Britannica, «Geber» (2024) Verified 20 Sep 2026
Thus, when an author who was probably a practicing Spanish alchemist began to write in about 1310, he adopted the westernized form of the name, Geber, to give added authority to his work.
- Britannica, «Geber» (2024) Verified 20 Sep 2026
He described the purification of chemical compounds, the preparation of acids (such as nitric and sulfuric), and the construction and use of laboratory apparatus, especially furnaces.
"Verified" means that on that day the quotation was found at the address given, word for word. No date means we have not been able to open the source yet, not that the quotation is wrong.
Further reading
Not evidence: these carry no quotation and support nothing we wrote. They are books and scans to read next.