Essays on the floating-matter of the air in relation to putrefaction and infection / by John Tyndall.

  • Tyndall, John, 1820-1893.
Date:
1881
Catalogue details

Licence: Public Domain Mark

Credit: Essays on the floating-matter of the air in relation to putrefaction and infection / by John Tyndall. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

    352/366 (page 330)
    A plan was therefore resorted to, by which the infusions were driven by atmospheric pressure through lateral chan- nels issuing from the centres of the bulbs. As before, each bulb was filled with one-third of an atmosphere of filtered air, and afterwards heated nearly to redness. When fully charged, the infusion rose higher than the central orifice, and no portion of the internal surface was wetted save that against which the liquid permanently rested. The lateral channel was then closed with a lamp without an instant’s contact being permitted to occur between any part of the infusion and the external air. It was thus rendered ab- solutely certain that the contagia exposed subsequently to the action of heat were to be sought, neither in the super- jacent air nor on the interior surfaces of the flasks, but in the body of the infusions themselves. By this method I tested in the first place the substance which, at an early stage of the inquiry, had excited my suspicion—without reference to which the discrepancy between the behaviour of infusions examined in the winter of 1875-76 and those examined in the winter of 1876-77 is inexplicable, but by reference to which the explanation of the observed discrepancy is complete ; I mean, the old hay which cumbered our laboratory floor. Four hours’ continuous boiling failed to sterilize bulbs charged with infusions of this hay. In special cases, more- over, germs were found so indurated and resistant that five, six, and, in one case, even eight hours’ boiling failed to deprive them of life. All the difficulties encountered in this long and laborious inquiry were traced to the germs which exhibited the ex- traordinary powers of resistance here described. They introduced a plague into our atmosphere—the other in- fusions, those of fresh hay included, like a smitten popula- tion, becoming the victims of a contagium foreign to themselves.1 It is a question of obvious interest to the scientific 1 A hard and wiry hay from Guildford, which I have no reason to consider old, was found extremely difficult to sterilize.