. Preventive medicine and hygiene. ithstand the pressure. Water is placed in the kettle and the heat is applied to the bottom, usually by means of several Bunsen gas jets. The apparatus is surrounded as high as the shoulder, where the lid is attached, with a metal jacket which serves the purpose of bringing the heat of the flame in contact with the entire surface of the kettle. The lid is made to fit tightly by means of screw bolts and a rubber gasket. A thermometer, pressure gage, safety valve and a small open-ing with a stopcock for the purpose of al-lowing the escape of the air are provided
. Preventive medicine and hygiene. ithstand the pressure. Water is placed in the kettle and the heat is applied to the bottom, usually by means of several Bunsen gas jets. The apparatus is surrounded as high as the shoulder, where the lid is attached, with a metal jacket which serves the purpose of bringing the heat of the flame in contact with the entire surface of the kettle. The lid is made to fit tightly by means of screw bolts and a rubber gasket. A thermometer, pressure gage, safety valve and a small open-ing with a stopcock for the purpose of al-lowing the escape of the air are provided. If all the air is not expelled from the ap-paratus the dead spaces will have a much lower temperature than that registered on the thermometer. For instance, the steam itself may register a temperature of 130° C, while test fluids exposed may only reach 70° to 80° C. Therefore, in using this form of sterilizer it is customary to allow the steam to escape in full force for several minutes before permitting the pressure to Fig. 157.—Bramhall-Deane Steam Sterilizer. PHYSICAL AGENTS OF DISINFECTION 1125 In the sterilization of liquids, for which this apparatus is frequentlyused, it is important, at the conclusion of the process, not to take offthe lid or open the valves, or in any other way release the pressure untilthe apparatus has cooled; otherwise the condensed steam causes a dimin-ished pressure, in which the heated liquids will boil energetically, resultingin a bubbling over, a blowing out of stoppers, or a bursting of the is therefore necessary to wait until the pressure is zero, as registeredon the gage; or, better, until the condensing steam produces a partialvacuum and the air is automatically sucked in through the vacuum valve.
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Keywords: ., bookauthorwh, bookcentury1900, bookdecade1910, booksubjecthygiene
