PASTEUR, LOUIS (1822-1895), French chemist, was born on Dec. 27,1822, at Dole, Jura, the son of a tanner. Shortly after wards his family moved to Arbois, where Louis attended the pri mary and secondary schools. In Oct. 1838 he was sent to a school in the Quartier Latin of Paris, preparatory to the Ecole normale, but his health broke down and he yearned for home. "If only I could smell the tannery once more," said he, "I should feel well." He was allowed to return to Arbois, but soon left to enter the Royal College of Besancon, where in 1840 he won his "bachelier es lettres." He then became assistant mathematical master in the college, securing in 1842 the "baccalaureat es sciences" with "mediocre" in chemistry attached to his diploma. Even in these early days the dominant note in Pasteur's life was sounded. To his sisters he writes : "These three things, will, work and suc cess, between them fill human existence." Throughout his entire life, work was his constant inspiration. On his deathbed he turned to his devoted pupils and exclaimed: "On en etes-vous? Que faites-vous?" ending with his favourite words, "Il faut travailler." In 1843 Pasteur was admitted fourth on the list to the ncole normale. He now attended the lectures of J. B. Dumas at the
Sorbonne, and thereby received his first incentive to the serious study of chemistry. Shortly afterwards, to his great joy, he became laboratory assistant to A. J. Balard. In 1848, having been successful at the examinations for the licence, the agregation and the doctorate, he accomplished his first startling piece of research, on racemic acid. Mitscherlich had shown in 1844 that the ordinary commercial acid rotated the plane of polarized light to the right, while the paratartrate or racemic acid possessed no rotary power. Being interested in crystals, Pasteur soon realized that the para tartrate contained two types of crystals. He separated them and found that their solutions when tested with a polariscope gave two contrary deviations. He then mixed an equal number of each kind and was able to procure the desired optical neutrality of racemic acid. Thus he had proved that this mysterious acid was made up of a right-hand tartaric acid and a left-hand one, and had inci dentally discovered a new class of isomeric substances. (See