. A text-book of bacteriology, including the etiology and prevention of infective diseases and a short account of yeasts, and moulds, haematazoa, and psorosperms. Bacteriology. 102 BACTERIOLOGY. paper becomes faiutly blue. If it has been made too alkaline, it can be neutralised by the addition of lactic acid. Finally, the mixture is heated for an hour in the water-bath. Ten niinvites before the boiling is completed, the white of an egg beaten up with the shell is added, and the liquid is then filtered while hot. For the filtration, the hot-water apparatus (Fig. 31) can be used with advantage,
. A text-book of bacteriology, including the etiology and prevention of infective diseases and a short account of yeasts, and moulds, haematazoa, and psorosperms. Bacteriology. 102 BACTERIOLOGY. paper becomes faiutly blue. If it has been made too alkaline, it can be neutralised by the addition of lactic acid. Finally, the mixture is heated for an hour in the water-bath. Ten niinvites before the boiling is completed, the white of an egg beaten up with the shell is added, and the liquid is then filtered while hot. For the filtration, the hot-water apparatus (Fig. 31) can be used with advantage, furnished with a filter of Swedish paper, which may be conveniently made in the follov/ing way :— About eighteen inches square of the best and stoutest filter paper is fii'st folded in the middle, and then creased into sixteen folds. The filter is made to fit the glass funnel by gathei'ing up the folds like a fan, and cutting off the superfluous part. The creasing of each fold should be made fii-mly to within half an inch of the apex of the filter, which part is to be gently inserted into the tube of the funnel. To avoid bursting the filter iit the point, the Ijrotli, when poured out from the flask, should be diieoted against the side of the filter with a glass rod. During filtivition the funnel should be covered over watli a circular plate of glass, and the pro- of filtration must be repeated, if necessar}', until a pale, straw- coloured, pei'fectly transparent filtrate results. The sterilised test-tubes are filled to about a thu-d of then- depth by pouring in the gelatine carefully and steadily, oi' by employing a small sterilised glass funnel. The object of this care is to prevent the mixture touching the part of the tube with which the plug comes into contact; otherwise, when the gelatine sets, the cotton- wool adheres to the tube and becomes a source of embarrassment in subsequent procedures. As the tubes are filled they are placed in the test-tube basket, and must
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Keywords: ., bookcentury1800, bookdecade1890, bookpublisherphila, bookyear1897
