438 



BLOOD AND LYMPH. 



or Ringer's solution, are injected into the veins immediately after 

 a severe hemorrhage, recovery is more certain; in fact, it is 

 possible by this means to restore persons after a hemorrhage that 

 would otherwise have been fatal. By an infusion of this kind, 

 particularly if at or somewhat above the body temperature, the 

 heart beat is increased, the volume of the circulating liquid is 

 brought to an amount sufficient to maintain approximately normal 

 conditions of pressure and velocity, and the red corpuscles that still 

 remain are kept in more rapid circulation and are thus utilized more 

 completely as oxygen carriers. If a hemorrhage has not been fatal, 

 experiments on lower animals show that the plasma of the blood is 

 regenerated with some rapidity, the blood regaining its normal vol- 



HaaioglobUL 



Fig. 176. To show the effect of hemorrhage upon the number of red and white cor- 

 puscles and the amount of hemoglobin. (Dawson.) The ordinates express the numbers 

 of corpuscles and also the percentages of hemoglobin as stated in the figures to the left. 

 The abscissas give the days after hemorrhage. The experiment was made upon a dog of 

 8.1 kgms. The hemorrhage, which lasted 2.3 minutes, was equal to 4.3 per cent, of the 

 body-weight. An equal amount of physiological saline (NaCl, 0.8 per cent.) was injected 

 immediately. 



ume within a few hours in slight hemorrhages, and in from twenty- 

 four to forty-eight hours if the loss of blood has been severe; but 

 the number of red corpuscles and the hemoglobin are regenerated 

 more slowly, getting back to normal only after a number of days or 

 after several weeks. The accompanying curves illustrate the results 

 of a severe hemorrhage (4.3 per cent, of the body-weight) followed 

 by transfusion of an equal volume of physiological saline. So far 

 as the red corpuscles and the amount of hemoglobin are concerned, 



