A leaf from the 15th century translation and critical study of the ‘Dialogues’ of Plato by Leonardo Bruni, called Aretino – $150,000 (£117,645) at Bonhams.

Of the six lots that found buyers, the most expensive, at $150,000 (£117,645), actually dated from the 15th century and was a translation from the Greek of the 5th century BC ‘Dialogues’ of Plato made by Leonardo Bruni, called Aretino, who has added his own learned discourse.

Described as a “museum quality” manuscript, it was last seen at auction in Germany in 1991 and later formed part of the Bibliotheca Philosophica Hermetica collections of JR Ritman.

Not so very far behind in price terms was a letter from a man who described himself as a philosopher of mathematics, Ludwig Wittgenstein.

Sent in 1935 to the German philosopher and physicist, Moritz Schlick, it takes as its subject the celebrated ‘incompleteness theorem’ published just a few years earlier by mathematician, logician and analytic philosopher, Kurt Gödel.

Described by Bonhams as “…a central document in the philosophy of mathematics that… reveals Wittgenstein at the height of his philosophic genius”, it sold at $110,000 (£86,275).

Unpublished Newton notes

Other high spots included, at $65,000 (£50,980), two pages of unpublished notes that, shortly after the ‘Great Plague of London’, were made by Isaac Newton after reading Jan Baptiste van Helmont’s 1667 book, De Peste. Among them he includes one quite repulsive-sounding potential remedy involving a dead toad.


The elusive signature of Nicolai Ivanovitch Lobachevski – $25,000 (£19,610) at Bonhams.

Sold at $25,000 (£19,610) was a letter of resignation from the post of Curator of Regional Education in Kazan bearing what the cataloguer called the ‘Black Pearl’ of scientific autographs.

It was the only example seen at auction in at least 50 years of the signature, using just his surname, of a Russian mathematician. His true claim to fame is as the discoverer of non-Euclidean geometry, but to many people he is much better known, I suspect, as the inspiration for one of Tom Lehrer’s most famous songs: ‘Nicolai Ivanovitch Lobachevski is his Name, Oy!’

The sale ran online from June 1-10.