Radical departures from the text of Apollonius
The symbol Rx, which we see on prescription slips from the physician’s office or in the windows of pharmacies, was once most commonly a brevigraph for recipere, which the third conjunction allows us to identify as the present infinitive of recipio, and which leads us to the countless quoted passages of things being taken back, or simply taken, in the pages of the Lewis & Short. But Lucia Pacioli also used the Rx glyph to signify radix or radices in the margins of his Summa Arithmetica (Venice, 1494). From radix we derive our word radish, which is, after all, an edible root.
If you look closely, you might detect this symbol in the image above, of fol.3v of the first Latin translation of the Conics of Apollonius of Perga, which was printed in Venice in 1537; a variant of Pacioli’s m for meno (-) also occurs, clearly demonstrating Giovanni Battista Memo’s debt to his predecessor. Ultimately, Frederico Commandino was a much better scholar, and his two-volume 1566 Apollonii Pergaei Conicorum Libri Quattuor would not be surpassed until Edmond Halley’s edition, the late (1654) appearance of Francesco Maurolico notwithstanding. But digressions on the complex and fascinating textual history of the Conics must wait for future posts.
For now, the most interesting aspect of Memo’s Latin editio princeps is his curious use of arithmetic to explain the geometrical propositions, which reveals far more about how mathematics was read in sixteenth-century Venice than it does about about the propositions themselves.