Further observations on the temperature at which bacteria, vibriones, and their supposed germs are killed when immersed in fluids or exposed to heat in a moist state : and on the causes of putrefaction and fermentation / by H. Charlton Bastian, M.A.

  • Bastian, H. Charlton.
Date:
[1873], [©1873]
Catalogue details

Licence: Public Domain Mark

Credit: Further observations on the temperature at which bacteria, vibriones, and their supposed germs are killed when immersed in fluids or exposed to heat in a moist state : and on the causes of putrefaction and fermentation / by H. Charlton Bastian, M.A. Source: Wellcome Collection.

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

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    not enable us to decide whether the exciting cause of this delayed turbi- dity is in part the living element whose vitality and rate of reproduction has been lowered by the heat, or whether the effects are wholly attribu- table to the mere organic matter of the inoculating compound. • So far, therefore, we have concomitant variations which are equally compatible with either h}'pothesis. But it will be found that each of the three succeeding arguments speaks more and more plainly against the possible influence of the living element, and in favour of the action of the organic matter of the inoculating compound, as an efficient exciting cause of the delayed putrefactions occurring in the cases in question. 3. As stated in my last communication *, when single drops of slightly turbid infusions of hay or turnip previously heated to 140° F. are mounted and securely cemented as microscopical specimens, no increase of turbi- dity takes place, although drops of similar infusions heated only to 122° F. do notably increase in turbidity (owing to the multiplication of Bacteria) when mounted in a similar manner. Under such restrictive conditions as these, in fact, a drop of an inoculated and previously heated organic infusion behaves in precisely the same manner as a drop of a similarly treated ammonic-tartrate solution. In each case, when heated to 140° r., turbidity does not occur, apparently because there are no living units to multiply, and because in these mere thin films of fluid dead ferments are as incapable of operating upon the organic fluids as they are upon the ammonic-tartrate solutions. 4. Because, in the case of the inoculation of fluids which are not easily amenable to the influence of dead ferments, such as a solution containing ammonic tartrate and sodic phosphate, this delayed turbidity does not occur at all. Such inoculated fluids become rapidly turbid when heated to 131° F., though they remain clear after a brief exposure to a tempera- ture of 140° F. When the living units in the inoculating compound are led, there is nothing left to induce turbidity in such solutions. The mere fact that these fluids do not undergo change when exposed to the air proves conclusively that they are very slightly amenable to the in- fluence of the ordinary dead organic particles and fragments ^ith which the atmosphere abounds. The absence of delayed turbidity in these fluids serves, therefore, to throw much light upon the cause of its occur- rence in the organic infusions. 5. And, lastly, I can adduce crucial evidence supplied by the Method of Difference, speaking with its accustomed clearness. Two portions of the same hay- or turnip-infusion can be inoculated in such a manner as to supply us with the information we require. In the one case we may employ a drop of a turbid ammonic-tartrate solution previouslv heated to 140° F., in which, therefore, the living units would certainly be killed ; whilst in the other we may add an unheated drop of the same turbid saline solution to the organic fluid, and then heat this mixture also to * Loc. cif. p, 228.