Letter containing the only description of the “caillou” by André Michaux to have survived. It was published in 1800 in theMagasin encyclopédique and is addressed to the citizens of France. Excerpt: "Permit me, citizen, through the columns of your newspaper, to acquaint admirers of Chaldean antiquities with a precious monument I brought back from Persia. It is a basalt stone of an elongated, rounded and slightly flattened shape, measuring 48 centimetres (one and a half feet) and weighing nearly 22 kilogrammes (44 pounds). This monument is covered in perfectly preserved inscriptions and figures. The letters or characters are formed of straight lines, without a combination of round or half-round forms, as seen in the characters of other languages. I found it a day’s journey from Baghdad, in the ruins of Semiramis, near the Tigris."

(Magasin Encyclopédique - an VIII - 1800, 6è année, tome 3, p. 86 and 87, Nouvelles littéraires, copy conserved at the Bibliothèque Nationale de France under reference number MNHN: D.: 4987 - Transcription by R. Pluchet)