PASTEUR, Louis (1822-95). Autograph manuscript notes for an experiment in fermentation, dated 20 April, and with observations 'très instructives' dated 15 and 20 March, initialled 'L.P.', one page, quarto (247 x 190mm); framed with a photo-engraving of Edelfelt's classic portrait of Pasteur in his laboratory.

PASTEUR, Louis (1822-95). Autograph manuscript notes for an experiment in fermentation, dated 20 April, and with observations 'très instructives' dated 15 and 20 March, initialled 'L.P.', one page, quarto (247 x 190mm); framed with a photo-engraving of Edelfelt's classic portrait of Pasteur in his laboratory.

Pasteur began his investigation of the process of fermentation in the early 1850s and the conclusions which he drew then -- particularly his rebuttal of the theory of spontaneous generation of bacilli -- laid the foundations for his later discoveries in the fields of biochemistry and medicine. This manuscript dates from the year in which the French Parliament recognised his achievements with a financial award.