The evolution of life / by H. Charlton Bastian.

  • Henry Charlton Bastian
Date:
1907
Catalogue details

Licence: In copyright

Credit: The evolution of life / by H. Charlton Bastian. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

    89/420 (page 65)
    There remains, therefore, an intermediate heat-zone (ranging from a little below 140° to a little below 158°?.), after an exposure to which the inoculated organic infusions are apt to become more slowly turbid, although inoculated saline solutions raised to the same temperature invariably remained unaltered. The cause of this difference was later on dealt with in another communication to the Royal Society. It is unnecessary, however, to go into this question now, since it is at present generally admitted by bacteriologists that Bacteria and Torulse in their active state, as they are found growing and multiply- ing in fluids, are invariably killed by a brief exposure to temperatures ranging between 140° and 158° F. (60°-70° C.)—and for the most part nearer to the former than to the latter limit. Then, again, besides Bacteria and Torulae, the bodies which are prone to show themselves at times in experimental vessels raised to much higher temperatures are ordinary Moulds. And in regard to such organisms Sachs says^: Of ninety-four ex- periments which were made by Tarnowski with all possible precautions, the result was that the spores of Penicillium glaucum and Rhizopus nigricans . . . heated in their proper nutrient fluids nevertheless entirely lost their power of germination at 54° or 55°C.[i3i°F.]. So far then the various experimental results upon the question of vital resistance to heat have yielded remarkably harmonious results. There is still another side to the question, however, which 1 Text-book of Botany, Transl. 1875, P- 651.