BACTERIOLOGY. 



t, g only touches i by three projecting ridges. 

 Section of i and g is shown at s. To put the ap- 

 paratus in use it is first levelled, then h is screwed 

 off and the cover n n removed. A mixture of two 

 parts of pure acid-free glycerine to one of distilled 

 water is poured into the cylinder until it flows out at 

 q, which is then closed, and the cover n n replaced.' 

 The manometers are filled with coloured water, and 

 k and / connected with the entrance and exit gas 

 tubing respectively. The pressure of the incoming 

 gas raises the bell B; and with it the valve d is 

 raised towards the opening at c c. The weight h, 

 which is replaced on g, by its downward pressure 

 counteracts this upward pressure of the gas and 

 opens the valve c c. Thus the flame is best regu- 

 lated in the morning, when the pressure is at a 

 minimum; then supposing an increase of pressure 

 occurs, the weight of h is overbalanced, B is raised 

 and with it d, and the gas supply proportionately 

 diminished by the gradual closing of the valved 

 opening. 



Reichert's Thermo-Regulator. This regu- 

 lator (Fig. 22) consists of three parts a hollow T 

 piece, a stem, and a bulb. The T piece fits like a 

 stopper in the upper widened portion of the stem. 

 One arm of the T is open, and connected with the 

 gas supply ; the vertical portion terminates in a 

 small orifice, and is also provided with a minute 

 lateral opening. The stem is provided with a 

 lateral arm, and this arm, the stem, and the bulb 



