ntation, Pasteur took up this
subject under particularly favourable conditions. His work and his
culture had given strength and finish to his natural aptitudes. In
1862, accordingly, he published a paper 'On the Organised Corpuscles
existing in the Atmosphere,' which must for ever remain classical. By
the most ingenious devices he collected the floating particles of the
air surrounding his laboratory in the Rue d'Ulm, and subjected them to
microscopic examination. Many of them he found to be organised
particles. Sowing them in sterilised infusions, he obtained abundant
crops of microscopic organisms. By more refined methods he repeated
and confirmed the experiments of Schwann, which had been contested by
Pouchet, Montegazza, Joly, and Musset. He also confirmed the
experiments of Schroeder and von Dusch. He showed that the cause
which communicated life to his infusions was not uniformly diffused
through the air; that there were aerial interspaces which possessed no
power to generate life. Standing on the Mer de Glace, near the
Montanvert, he snipped off the ends of a number of hermetically sealed
flasks containing organic infusions. One out of twenty of the flasks
thus supplied with glacier air showed signs of life afterwards, while
eight out of twenty of the same infusions, supplied with the air of
the plains, became crowded with life. He took his flasks into the
caves under the Observatory of Paris, and found the still air in these
caves devoid of generative power. These and other experiments,
carried out with a severity perfectly obvious to the instructed
scientific reader, and accompanied by a logic equally severe, restored
the conviction that, even in these lower raches of the scale of being,
life does not appear without the operation of antecedent life.

The main position of Pasteur has been strengthened by practical
researches of the most momentous kind. He has applied the knowledge
won from his enquiries to the preservation of wine and beer, to the
manufacture of vinegar, to the staying of the plague which threatened
utter destruction of the silk husbandry of France, and to the
examination of other formidable diseases which assail the higher
animals, including man. His relation to the improvements which
Professor Lister has introduced into surgery, is shown by a letter
quoted in his Etudes sur la Biere. [Footnote: 1 P. 43.] Professor
Lister there expressly thanks Pasteur for having given him the only