Micro-organisms in water : their significance, identification and removal, together with an account of the bacteriological methods employed in their investigation ... / by Percy Frankland and Mrs Percy Frankland.

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 investigation ... / by Percy Frankland and Mrs Percy Frankland. 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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    which for experimental purposes is required to be sterilised without chemical change, these Chamberland and Berkefeld filters are extremely useful (see experi- ments made by Percy Frankland on the vitality of the anthrax bacillus in various waters, p. 3] 4 ; the sterility of the water was secured by means of a Chamberland filter). In those cases in which it is desired to separate the bacterial products from the micro-organisms them- selves such filtration is invariably resorted to. Bitter1 has made experiments on the filtration of liquids turbid from the growth of bacteria, and also of albuminous fluids, by means of the Berkefeld filter. He has found that even the bacillus of mouse septicemia, which is one of the smallest known organisms, growing in broth, is •entirely removed when the latter is passed through the above filter. Experiments were also made with blood- serum, and it was found that even putrid blood-serum may be not only quickly clarified, but the organisms entirely removed by its means. For this purpose it is best to use the more porous cylinders. Such a cylinder was found capable of filtering 680 c.c. in twenty-five minutes. In the case of fresh serum a cylinder of similar construction yielded in thirty minutes 800 c.c. •of clear sterile serum. It is necessary to frequently wipe the cylinder whilst the filtration is going on. Milk may also be deprived of all its fat and a clear sterile serum obtained by filtration through such porous cylin- ders. For the subsequent cleansing of the filter see p. 176. This method of sterilisation, therefore, may be used with great advantage for many laboratory purposes. Gases, again, are readily deprived of any micro- organisms they may contain in suspension by passage 'Die Filtration bacterientriiber und eiweisshaltiger Fliissigkeiten durcli Kieselguhrfilter.' Zcitschrift fur Hygiene, x. 1890, p. 155.