396 



Mr. 1). T. Harris. 



arterioles and capillaries, probably, remain dilated until the asphyxial products 

 are removed (fig. 13). The long upward curve corresponds to the stage of 

 " passive hyperasinia " while the swelling a few seconds after the release of the 

 compression is a true active hyperaemia ; the former is therapeutically 

 regulated in Bier's treatment, though even here the long application of a 

 tourniquet may also involve another doubtful factor — the swelling of the 

 body colloids (M. Fischer, 1920). 



Fig. 13. 



Both ischaemia and congestion produce like effects and the asphyxial products 

 arising from them are additive (fig. 14). A corresponding additive effect is 

 obtained with the metabolites of activity and asphyxial products (fig. 15), 

 from which a similarity between these substances may be inferred. 



Chemical Vaso-dilator Substances: Schwarz and Lemberger (1911) found 

 that the injection of 1 c.c. of molar HC1 into the central end of the left 

 subclavian artery caused obvious dilatation of the blood vessels of the sub- 

 maxillary gland. Comparing different acids, their action was not found to 



Fig. 14. 



