. Pathogenic micro-organisms. A text-book of microbiology for physicians and students of medicine. (Based upon Williams' Bacteriology). Bacteriology; Pathogenic bacteria. THE CULTIVATION OF MICRO-ORGANISMS 121 cooling the mercury falls and allows gas to flow again through the larger opening. In this way the supply of gas is made large whenever the temperature is a little below the desired temperature and very small whenever the temperature rises above that point, and the temperature varies within a slight range. The Reichert regulator is designed to operate according to these principles, and v
. Pathogenic micro-organisms. A text-book of microbiology for physicians and students of medicine. (Based upon Williams' Bacteriology). Bacteriology; Pathogenic bacteria. THE CULTIVATION OF MICRO-ORGANISMS 121 cooling the mercury falls and allows gas to flow again through the larger opening. In this way the supply of gas is made large whenever the temperature is a little below the desired temperature and very small whenever the temperature rises above that point, and the temperature varies within a slight range. The Reichert regulator is designed to operate according to these principles, and various modifications of this regulator are on the market. In many of these instruments the larger supply is only imperfectly shut off at the desired temperature, and, where the weight of the mercury is reHed upon to stop this opening, the gas may often bubble out through it unless special precau- tions are taken to regulate the pressure of the gas supply. A modification of this type of regulator devised by Mac NeaP overcomes this difiiculty (see Fig. 50). The inlet tube A leads through the wall of the chamber D, to which it is fused, into an inner upright tube, BC. Near the upper end of this upright is a small opening, 0, which allows the minimum supply of gas to pass to the burner to avoid extinction of the flame. The lower end of this upright tube fits quite closely the bot- tom of the chamber D, around the op ening leading into the capillary tube, EF. This end is adjusted so close to the bottom that mer- cury will net pass through, between inner and outer tube at less that twenty millimeters mercury pressure, yet not so close but than an abundant supply of gas may'pass. The proper adjust- ment of this part must be throughly tested before the instrument leaves the factory. The upper end of the upright, BC, is closed by a ground glass stopper, which also closes the top of the outer chamber, D. In the ground surface of this stopper a gamma- shaped (r) groove is cut, the vertica
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectbacteri, bookyear1920
