Louis Pasteur

11 Pages 2874 Words

ight with reference to the plane of orientation which I just mentioned, whereas the facet of asymmetry was inclined to my left in the other. The paratartrate appeared as a mixture of two kinds of crystals, some asymmetric to the right, some asymmetric to the left.
A new and obvious idea soon occured to me. These crystals asymmetric to the right, which I could separate manually from the others, exhibited an absolute identity of shape with those of the classical right tartrate. Pursuing my preconceived idea, in the logic of its deductions, I separated these right crystals from the crystallized paratartrate; I made the lead salt and isolated the acid; this acid appeared absolutely identical with the tartaric acid of grape, identical also in its action on polarized light. My happiness was even greater the day when, separating now from the paratartare the crystals with asymmetry at their left, and making their acid, I obtained a tartaric absolutely similar to the tartaric acid of grape, but with an opposite asymmetry, and also with an opposite action on light. Its shape was identical to that of the mirror image of the right tartaric acid and, other things being equal, it rotated light to the left as much in absolute amount as the other acid !
did it to the right.

"I remember hurrying from the laboratory and grabbing one of my chemistry assistants and excitedly telling him that 'I have made a great discovery...I am so happy that I am shaking all over and am unable to set my eyes against the polarimeter.' At this time, I was twenty-five years old and had only been doing research for two years. " (Dubois, 27-28)
Before my work could be presented to the public it had to be verified in the presence of a notable scientist, in this case, Jean Baptiste Biot. I was called to 'repeat before his eyes the several experiments and he gave me a sample of racemic acid which he had himself previously examined and found to be quite inactive toward po...