César Julien Jean Legallois (Feb 11, 1770 to Feb 10, 1814)
Submitted by Alan Rogol
Legallois, an experimental physiologist and physician, anticipated the concept of internal secretion, originally stated as de Bordeu’s speculative hypothesis, in his Doctoral Thesis [1801]: Le sang est-il identique dans tous les vaisseaux qu’il parcourt? [Is the blood the same in all vessels it moves through?]. He described that arterial blood was the same for all of the organs, but its composition changed in its course through an organ and thus each organ had its influence upon all of the others through the blood. In fact, he devised an equation to define the product of the gland: Arterial blood = such secretion + corresponding venous blood
[Oeuvres de Legallois, vol 2, Paris, 1830, p. 209]