QUANTITATIVE ESTIMATION OF GASES OF THE BLOOD. 



77 



advisable in the analysis of the gases of the blood to evacuate at once the blood 

 discharged from the vein into the receptacle, because on standing outside of the 

 body the amount of oxygen undergoes a diminution. 



Mayow, in 1670, was the first to observe gases arise from the blood in a vacuum, 

 and Priestley demonstrated the presence of oxygen and Davy that of carbon 



FIG. 20. Diagrammatic Representation of Pfliiger's Pump for the Extraction of the Gases of the Blood. 



dioxid. Magnus, in 1857, investigated the percentage-composition of the gases 

 of the blood. The important recent investigations have been made principally 

 by Loth. Meyer, in 1837, and by C. Ludwig and Pfliiger and their pupils. 



QUANTITATIVE ESTIMATION OF THE GASES OF THE BLOOD. 



The evacuated gases consist of oxygen, carbon dioxid, and nitrogen. 



The gases of the blood obtained with the aid of the pump will be found in 

 the eudiometer-tube (Fig. 20, J), an accurately graduated glass tube in w r hose 



