328 



AGRICULTURAL ANALYSIS 



terior of the bulb E should be of such a shape, as to allow each 

 drop of mercury to fall at once into F without accumulating in 

 large quantity and being discharged in mass. The third arm of 

 the tee, a", is bent upwards at the end and passes into a mercury 

 sealing tube, D, where it is connected by means of a rubber tube 

 with the delivery tube from the furnace. The flow of the mer- 



Fig. 14. Mercury Pump and Azotometer. 



cury is regulated by the clamp C, and care should be taken that 

 the supply does not get so low in I as to permit air bubbles to 

 enter A. The manometer B dips into the tube of mercury H. 

 A pump thus constructed is simple, flexible, and perfectly tight. 

 The only part which needs to be specially made is the three way 

 tube T, and the one in use here was blown in our own laboratory. 

 The bent end of the delivery tube F may also be united to the main 



