Three or four years ago Florence1 of Lyons secured a peculiar formation of crystals when semen was brought into contact with concentrated solutions of iodin. While he failed to find this reaction in other fluids from the human body and in semen from animals, he nevertheless wisely refrained from claiming an absolutely diagnostic importance for these crystals. He looked upon the crystals as indicating the probable presence of semen, and that in such cases one should look so much more carefully for the absolutely positive evidence, namely, the presence of spermatozoa.
The medicolegal importance of demonstrating that stains are due to seminal fluid is of course very great. The investigations of Florence were painstaking and extensive, and his results have received abundant corroboration. In America, W. Johnston and Whitney2 have studied the reaction extensively. Richter3 tried all the substances which are demonstrable in the semen, and obtained
CONCERNING THE IODIN REACTION (FLORENCE'S REACTION) WITH SEMINAL AND OTHER FLUIDS.. JAMA. 1898;XXXI(11):609-610. doi:10.1001/jama.1898.02450110051004