188 



PRACTICAL PHYSIOLOGY 



pump introduced by Leonard Hill. For other methods see Barcroft's 

 papers on the subject in the Journal of Physiology or Ergebnisse der 

 Physiologie, 7*" Jahrgang, 1908. 



The pump consists of a mercury reservoir A, which is connected 

 with a second reservoir B by means of pressure tubing. The con- 

 nection is surrounded by a mercury cup. The upper end of B is closed 



FIG. 184. Hill's blood-gas pump. 



by a three-way tap fitted with mercury cups. By means of this tap B 

 can be put in connection with either the tube E leading to the blood- 

 receiver F, or with the tube C leading to the eudiometer H. The 

 blood-receiver F is constructed of three bulbs, so as to prevent the blood 

 frothing over into B during the extraction of the gases. On the lower 

 end of F is a three-way tap. To the upper end of F is fixed a piece of 

 thick small-bored pressure tubing provided with a clip. 



The mercury used to fill the pump must be cleaned and the pump 



