Applied bacteriology; an introductory handbook for the use of students, medical officers of health, analysts and sanitarians / by T.H. Pearmain and C.G. Moor.

  • Moor, C. G. (Cresacre George)
Date:
1898
Catalogue details

Licence: Public Domain Mark

Credit: Applied bacteriology; an introductory handbook for the use of students, medical officers of health, analysts and sanitarians / by T.H. Pearmain and C.G. Moor. Source: Wellcome Collection.

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

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    and the Micrococcus pneumonue crouposce are cases m point. By extending the time, a still lower temperature will effect the same result. Chauveau found the anthrax bacillus to be killed by twenty minutes’ exposure to a temperature of 50° C.; and Brieger also found that he could sterilize diphtheria cultures by exposure for some hours to the same temperature. As already mentioned, there are micro-organisms (gene- rally knowm as the ‘ thermophilic ’ bacteria) that are able to multiply at a temperature of 65° to 70 C. Miquel, in 1881, found a motionless organism in the water of the Seine, which grew in broth at 69 to 70 C. Van Tieghem has also discovered several species which grow at about the same temperature. With regard to the resisting power of ‘ spores ’ to moist heat, those of many pathogenic bacteria are quickly killed by a very short exposure to 100 C. ( = 212 F.). There are others, such as those of tuberculosis, infantile diarrhoea (Flligge), puerperal fever, and symptomatic anthrax, which, after being dried, may resist boiling for many hours. Spores of certain non-pathogenic species may resist the boiling-water temperature (100° C. = 212° F.) for as much as sixteen hours. In view of the fact that the existing organisms of some of the most dangerous infectious diseases, such as small-pox and scarlet fever, are as yet undiscovered, no distinction can be drawn for practical purposes between the resistance of pathogenic and that of non-pathogenic organisms, and measures of disinfection must, so far as possible, be chosen so as to be capable of destroying the most resistant organisms. Steam for disinfecting purposes must always be saturated, and not superheated; that is to say, it must not be raised above the temperature at which under the existing pressure