148 



THE VASCULAR SYSTEM 



similarly is accompanied by constriction of the vessels of the 

 limbs. The cortex discharges motor impulses and alters the 

 circulation in accordance with the needs of the moving parts. 

 E. Weber has recorded in man the volume of the arm by means 

 of a plethysmograph, and the volume of the abdominal organs by 

 a rectal sound with balloon attached to the end of it, the sound 



' 



If 



r\r 



I vj * 



FIG. 20. 1, Volume of abdominal organs ; 2, volume of arm ; 3, respiration. 

 From to + , suggestion to hypnotised subject of his execution. 



being connected to a strong tambour. He also has repeated 

 Mosso's experiment of placing a man in the horizontal posture on 

 a long balanced board and seeing whether the head or feet end 

 becomes heavier in different emotional states. Weber put the 

 abdomen mostly on the foot side of the axis, instead of on the 

 head side as Mosso, and balanced by weights on the head side. He 

 found that mental work and painful emotions determine blood 

 to the abdomen, while pleasurable ideas and those of active move- 

 ment send blood from the abdomen into the peripheral parts. 



