He discovered that blood remained partially fluid for several hours in a vulcanized India-rubber tube but clotted promptly if placed in an ordinary cup. He concluded that blood coagulation is caused by “the influence exerted upon it by ordinary matter, the contact of which for a very brief period effects a change in the blood, inducing a mutual reaction between its solid and fluid constituents, in which the corpuscles impart to the liquor sanguinis a disposition to coagulate.”
