. 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. ]14 BACTERIOLOGY. plugged sterilised test-tubes. These should be filled, with a sterilised pipette, to about one-third of their capacity. Formerly the tubes were sterilised by Tyndall's process of dis- continuous sterilisation. The tubes were placed in Koch's serum sterilisei-, with the temperature maintained for an hour or more at .56° C, and this was repeated for six successive days, the temperature on the last day be
. 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. ]14 BACTERIOLOGY. plugged sterilised test-tubes. These should be filled, with a sterilised pipette, to about one-third of their capacity. Formerly the tubes were sterilised by Tyndall's process of dis- continuous sterilisation. The tubes were placed in Koch's serum sterilisei-, with the temperature maintained for an hour or more at .56° C, and this was repeated for six successive days, the temperature on the last day being gradually raised to 60° C. This completed the stei-ilisation, and to solidify the serum the tubes were arranged in the inspissator at the angle required, and the temperature was kept between 65° 0. and 68° C. Directly solidification took place the tubes were removed. The new process is much less tedious, and consists in taking every possible pre- caution to obtain the blood without contiimination by bac- teria in the air or in the vessels employed. There is then no need to sterilise the serum, and it can be coagu- lated immediately. The tubes are tested by placing them in an incubator at .37° C. for a week, and if any show signs of contamination they are discarded, and the rest can be used or kept in stock. The serum should then pi'esent the chai-acter of being hard, solid, of a pale straw colour, transparent. A little liquid collects at the lowest point, and the serum is sometimes milky in appearance at its thickest part. Loffler's Blood Serum is prepared by mixing two-thirds of fresh serum with one-third of broth, prepared in the usual way but with the addition of 1 per cent, grape-sugar. The mixture is decanted into test-tubes, avoiding the formation of air-bubbles, and it is then coagulated in the usual wa^-. The sei'um may be employed not only in test-tubes, but also in small flasks, glass capsules, or other vessels, all of which must be cleansed and sterilis
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Keywords: ., bookcentury1800, bookdecade1890, bookpublisherphila, bookyear1897
