INCUBATORS. H 



of wood with holes bored in it to contain dropping-bottles may be 



placed in the upper left hand drawer. In this way the stains are as 



accessible as if they encumbered the 



desk. It is advisable to paint the 



inside of this drawer black so that the 



light may not cause the staining 



reagents to deteriorate. 



Ordinary glass salt cellars will be 

 found very useful, where the watch- 

 glass is employed. They may also be 



wrapped, sterilized and used to con- 



. FIG. 5. Rice cooker. 



tain fluids for inoculating, etc. 



For use in making loops and needles, platinum wire of 26 gauge 

 will be found most suitable. The handle made of glass rocNis pref- 

 erable to the metal ones. 



INCUBATORS. 



\\hen gas is obtainable, the maintaining of a constant temperature 

 for the body temperature incubator (38 C.) and the paraffin oven 

 (60 C.) is best secured by the use of some of the various types of 

 thermo-regulators. The Reichert type is the one in general use, 

 although there are many features about the Dunham and Roux 

 regulators which are advantageous. 



If the pressure of the gas-supply varies from time to time, it is 

 essential to regulate this by the use of a gas pressure regulator (Murrill's 

 is a cheap and satisfactory one). 



Incubators, controlled electrically, can be obtained of certain 

 foreign makers, and are quoted in catalogues of American dealers. 

 It is probable that the Koch petroleum lamp incubator is the most 

 satisfactory one where gas is not obtainable. They should be of all 

 metal construction, and not with a wood casing, on account of the 

 danger from fire. They cost from twenty-five to fifty dollars. 



An incubator may be extemporized by putting the bulb of an incan- 

 descent electric lamp in a vessel of water. The proper temperature 

 may be obtained by increasing the amount of water or by covering the 

 opening more or less completely with a towel. The test-tubes to be 



