Some of his opponents thought to attack him on another point by denying him the priority of the use of carbolic acid. Lister never claimed that priority, but his enemies took pleasure in recalling that Jules Lemaire, in 1860, had proposed the use of weak carbolic solution for the treatment of open wounds, and that the same had been prescribed by Dr. Déclat in 1861, and also by Maisonneuve, Demarquay and others. The fact that should have been proclaimed was that Lister had created a surgical method which was in itself an immense and beneficial progress; and Lister took pleasure in declaring that he owed to Pasteur the principles which had guided him. At the time when Pasteur received the letter above quoted, which gave him deep gratification, people in France were so far from all that concerned antisepsis and asepsis, that, when he advised surgeons at the Académie de Médecine to put their instruments through a flame before using them, they did not understand what he meant, and he had to explain-- “I mean that surgical instruments should merely be put through a flame, not really heated, and for this reason: if a sound were examined with a microscope, it would be seen that its surface presents grooves where dusts are harboured, which cannot be completely removed even by the most careful cleansing. Fire entirely destroys those organic dusts; in my laboratory, where I am surrounded by dust of all kinds, I never make use of an instrument without previously putting it through a flame.” Pasteur was ever ready to help others, giving them willing advice or information. In November, 1874, when visiting the Hôtel Dieu with Messrs. Larrey and Gosselin, he had occasion to notice that a certain cotton-wool dressing had been very badly done by a student in one of Guérin’s wards. A wound on the dirty hand of a labouring man had been bandaged with cotton wool without having been washed in any way. When the bandaging was removed in the presence of Guérin, the pus exhaled a repugnant odour, and was found to swarm with vibriones. Pasteur in a sitting of the Académie des Sciences, entered into details as to the precautions which are necessary to get rid of the germs originally present on the surface of the wound or of the cotton wool; he declared that the layers of cotton wool should be heated to a very high temperature. He also suggested the following experiment: “In order to demonstrate the evil influence of ferments and proto-organisms in the suppuration of wounds, I would make two identical wounds on the two symmetrical limbs of an animal under chloroform; on one of those wounds I would apply a cotton-wool dressing with every possible precaution; on the other, on the contrary, I would cultivate, so to speak, micro-organisms abstracted from a strange sore, and offering, more or less, a septic character.