Micro-organisms in water : their significance, identification and removal, together with an account of the bacteriological methods employed in their investigaion, specially designed for the use of those connected with the sanitary aspects of water-supply / by Percy Frankland and Mrs. Percy Frankland.

  • Frankland, Percy, 1858-1946.
Date:
1894
Catalogue details

Licence: Public Domain Mark

Credit: Micro-organisms in water : their significance, identification and removal, together with an account of the bacteriological methods employed in their investigaion, specially designed for the use of those connected with the sanitary aspects of water-supply / by Percy Frankland and Mrs. Percy Frankland. 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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    Thermometer Lid freely from the top. In this way a uniform tempera- ture of 100° C. is obtained, and for the sterilisation of o-lass and other vessels an exposure of from one to two hours is neces- sary. In the case of some culture materials, however, such pro- longed heating to so high a temperature would cause serious alteration, and the prac- tice of intermittent steri- lisation (Tyndall) is then resorted to. This me- thod is also of impor- tance in the case of those materials, such as potatoes, in which one Water-gauge Ring of flames Fig. 1.—Koch's Steam Stbbilisee. exposure only to this temperature does not actually ensure sterility. Tyndall's plan is to submit substances to a high temperature for a short time on three to five successive days, and in the preparation of culture media containing gelatine this discontinuous sterilisation is of primary importance, as prolonged steaming greatly reduces the melting-point of the gelatine. Sterilisation may also be effected by simply boiling the articles in water ; thus in the disinfection of instruments—syringes &c. used in animal inoculations this may frequently be resorted to with advantage. In some exceptional cases, e:g., in the sterilisation of soil, high-pressure steam may be very conveniently used; thus certain spores were found by GrL >big ('Zeitsch. f. Hygiene,' iii. [1887], p. 332) to resist the ordinary process of steaming for upwards of three hours, whilst