RESPIRAI^ION. 



105 



hemoglobin blood holds about two fifths its bulk of carbon 

 dioxid, while hemoglobin blood has nearly one half its 

 bulk of carbon dioxid. 



THE GASES IN THE BLOOD. 

 From 100 volumes of May be obtained 



Oxygen. Carbon dioxid. Nitrogen. 



Oxyhemoglobin (arterial) blood . 2ovols. 4ovols. i to 2 vols. 



Hemoglobin (venous) blood . . lovols. 46 vols. i to 2 vols. 



Illustration of the Changes in the Color of the Blood. The 



changes that take place in the color of the blood, both in the lungs 

 and in the tissues of the other parts of the body, may be illustrated as 



Fig. 47. 



follows : Prepare a heart as directed on page 45. Use for the liquid a 

 strong solution of litmus, neutralized or slightly alkaline ; place in the 

 throat of each funnel a small sponge. Saturate with ammonia the 

 sponge in the funnel representing the capillaries of the body, and 



