. A text-book of bacteriology; a practical treatise for students and practitioners of medicine. Bacteriology. THE DESTRUCTION OP BACTERIA 91 .^,^J^ strong copper kettle of about 34 cm. diameter by cm. height. This is completely closed except for two openings in the slightly domed top, one of which is the exit vent, the other, laterally placed, is for purposes of filling and is closed by a screw stopper. The kettle is set up on a metal stand over an alcohol lamp, so arranged with a double circle of burners that heating may be carried out rapidly. The tank is filled with a solution of formal
. A text-book of bacteriology; a practical treatise for students and practitioners of medicine. Bacteriology. THE DESTRUCTION OP BACTERIA 91 .^,^J^ strong copper kettle of about 34 cm. diameter by cm. height. This is completely closed except for two openings in the slightly domed top, one of which is the exit vent, the other, laterally placed, is for purposes of filling and is closed by a screw stopper. The kettle is set up on a metal stand over an alcohol lamp, so arranged with a double circle of burners that heating may be carried out rapidly. The tank is filled with a solution of formalin of a strength of from 8 to 10 per cent (commercial formalin 1:4). The apparatus permits the evaporation of large quantities of fluid in a short time (3 hters in one hour). When the lamp is left in a closed room care should be taken to fill it with a quantity of alcohol proportionate to the amount of fluid to be evaporated. This, according to v. Brunn, is about one-quarter of the volume of formalin solu- tion used. By using liters of 8 percent formalin for each 1,000 cubic feet of space, this apparatus is said to yield a concentration of formaldehyde of about 25 grams to the cubic meter, a strength sufficient to complete surface disinfection within seven hours. To do away with the use of hquid formalin solutions, a meth- od has been devised which de- pends in principle upon the breaking up by heat of the solid polymer of formaldehyde (trioxymethylene). The apparatus (trade name, "Schering's Paraform Lamp") as described by Aronson ^ consists of a cylindrical mantle of sheet-iron placed upon a stand and supplied below with an alcohol lamp. Set into the top of the mantle is a small chamber, into which 1 gram tablets of trioxymethylene are placed. The alcohol lamp, so placed that the wicks project but slightly—to avoid overheating—is lighted, and the formalin generated passes out through slits in the upper case, minghng with the water vapor and other gases liber
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Keywords: ., bookcentury1900, bookdecade1910, bookpublishernewyorkandlondonda
