THERMO-REG ULA TORS. 



129 



the tube e, and is provided a short distance above this 

 point with a capillary opening, g, in one of its sides. 



When ready for use the cylinder e is filled with mer- 

 cury up to about the level shown in the figure. It is 



Fig. 82. 



Mercurial thermo-regulator. 



then allowed to stand, or is suspended, in the bath the 

 temperature of which it is to regulate. The rubber 

 tubing coming from the gas-supply is attached to the 

 outer end of the glass tube a, and the tube going to the 

 burner is slipped over the branch tube b. The gas is 



