PASTEUR, LOUIS. - ANNOUNCING THE DISCOVERY OF "MOLECULAR ASSYMETRY"

Mémoire sur la relation qui peut exister entre la forme cristalline et la composition chimique, et sur la cause de la polarisation rotatoire; (Extrait). (Séance du Lundi 22 Mai 1848).

(Paris, Bachelier), 1848. 4to. No wrappers. In: "Comptes Rendus Hebdomadaires des Séances de L'Academie des Sciences", Tome 26, No 21. Pp. (529-) 548. (Entire issue offered). Pasteur's paper: pp. 535-538. Clean and fine.

First appearance of the announcement of Pasteur's momentous and revolutionary discovery of "molecular assymetry" and founding the science of Polarimetry.
The discovery was first announced by Pasteur in may 1848 by the printing of the preliminary report of only 4 short pages, in order to establish priority (the paper offered). A more full exposition was published the same year in "Annales de Chimie et de Physique", 3me Series - Tome XXIV.

"In 1848....Pasteur studied the crystals of tartrates (one of the substances that exhibited the now-clockwise, now-counterclockwise effect) under the microscope and found that the xcrystasls were mirror images of the others. The two crystals resemmbled each other as a right-hand glove resembles a left-hand glove....This was a revolutionary discovery and it took some courage to announce it. A few years before, the well-known chemist Mitscherlich had studies the same tartrate crystals and declared them all to be identical. Pasteur was only a twenty-sic-year-old unknown. neverthelless he announced his findings and went before Biot to repeat the separation ofthe crystals before the eyes of the aged authority in the field. Biot was convinced and Pasteur received the Rumford medal of the Royal Society for his work....Pasteur had thus founded the science of polarimetry in which the measurements of the manner in which the plane of polarized light was twisted could be used to help to determine the structure of organic substance, to follow various chemical reactions, and so on."(Asimov).

Leicester & Klickstein "A Source Book of Chemistry", p. 374-379).

Order-nr.: 49456