Fermentation organisms : a laboratory handbook / by Alb. Klöcker; translated from the german by G. E. Allan and J. H. Millar.
- Date:
- 1903
Licence: In copyright
Credit: Fermentation organisms : a laboratory handbook / by Alb. Klöcker; translated from the german by G. E. Allan and J. H. Millar. 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 placed on the side tube of the opening of which is still in the flame. This procedure may perhaps seem somewhat complicated after reading through the above description, but if it has been tried in practice it will be found to ofler no special difficulty but only requires practice. The very first exer- cises can be performed with flasks which contain ordinary water ; then flasks may be used containing sterile wort, allowing them to stand between experiments in order to see if infection has been avoided. After some practice flasks should be used which contain sterilised yeast water or meat extract in order to see if these remain sterile with constant use ; this is much more difficult, as most bacteria develop readily in these licjuids, which does not happen in wort. If it is seen that these flasks remain sterile after they have been worked with for several days, it may be then assumed that the necessary experience has been ac(]uired. A similar method to the above is adopted in using- Hansen flasks which are also provided with side tubes. But the air entering does not require to be heated after passing through the cotton wool in the cap, since the latter- acts as a filter. Sterilised pipettes have to be used in experimenting with Freudenreich, Chamberland and Erlenmeyer flasks. These flasks also are of course always sterilised before- hand with the flame. This has to be done also when a part of the contents of a Pasteur flask is to be passed into one of the above-named flasks. If only small quantities of liquid are being used, sterilised glass rods or metal wires may replace the pipettes. These experiments should be performed in the sterile cupboard or in the sterile room, and it is necessary to work very quickly. Exercises ought also to be performed with the pipettes as with the Pasteur flasks,](https://iiif.wellcomecollection.org/image/b21900395_0120.jp2/full/800%2C/0/default.jpg)
