246 



BACTERIOLOGY. 



The author's thermo-regulator ', shown in Fig 1 . 37, is 

 intended to overcome the difficulties mentioned. Although, 

 apparently, more complicated than the ordinary regulator, 

 it nevertheless is easily adjusted and is extremely sensitive. 

 The gas tubing- is attached to the strong, wide inflow and 



outflow tubes (a! and a"} and is 

 thus independent of the regulat- 

 ing parts. The upper portion 

 consists of the three parts A, B 

 and C, the arrangement and 

 working of which is readily 

 understood from the illustra- 

 tion. The gas enters the inflow 

 tube a', and passes through the 

 opening &, into the interior of B. 

 On account of the stopper C the 

 gas cannot leave except by pass- 

 ing through the opening c into 

 the narrowed portion of B. It 

 leaves this delivery tube at the 

 lower end (/) and through the 

 opening d. The latter supplies 

 the minimum amount of gas 

 necessary to keep the lamp 

 burning. This supply can now 

 be regulated with absolute pre- 

 cision. The opening d is made 

 through the parts B and C. By 

 turning C, the opening through 

 this part becomes excentric to 

 that of B, and hence, the minimum supply of gas is thus 

 diminished. 



The delivery tube / should not be too narrow and 

 should almost touch the bottom of A. The first droplet of 



1 Centralblatt fiir Bakteriologle, 23, p. 1054, 1898. This instru- 

 ment can be obtained of Greiner and Friedrichs, Stiitzerbach i. 

 Thuring-en. 



FIG. 37. The author's thermoregulator. 



