Methods used since 1922 for determining the speed1 with which blood flows in man depend for the most part on production of a reaction in one part of the body (for example, the tongue) to a substance injected into a vein in another part of the body (for example, the median basilic vein). The time elapsing between injection of the substance and detection of the reaction is known as circulation time.
Substances used are potassium ferrocyanide,2 an active radium deposit,3 calcium salts,4 magnesium sulfate,5 dehydrochloric acid,6 saccharin,7 various dyes,8 ether,9 histamine10 and sodium cyanide.11 These substances have been used chiefly for determining the speed of blood flow in a pathway consisting of peripheral veins, pulmonary arteries and veins, chambers of the heart and part of the arteries originating from the left ventricle. The circulatory pathway from the arm to
KVALE WF, SMITH LA, ALLEN EV. SPEED OF BLOOD FLOW IN THE ARTERIES AND IN THE VEINS OF MAN. Arch Surg. 1940;40(2):344-351. doi:10.1001/archsurg.1940.04240010184013