Door: Prof. Joseph Gal (University Of Colorado School of Medicine, Denver, CO, USA)

Despite popular belief, Louis Pasteur (1822 - 1895) was trained as a chemist and not as a microbiologist. After obtaining a doctorate he began a crystallographic study of tartaric acid (TA) and its salts. 

In 1848 he found the sodium ammonium salt of racemic TA to be a mixture of two crystal forms with right- or left-leaning hemihedral facets, respectively, and related as object and its mirror image.

Pasteur thereby identified, for the first time, the two enantiomers of a chiral substance, and recognized the existence of molecular chirality. He was 25 years old.

He worked another 10 years on chirality but then turned to microbiology and infectious diseases. Pasteur was not the 'lay saint' that his hagiographic biographers portrayed. As a scientist and man he had admirable traits but also human failings.

Nevertheless, his discoveries place him among the greatest scientists of all time.

Professor Joseph Gal is an authority on historical lectures about great scientists and a passionate
and vivid speaker on these topics.