L. Deslandes, A Treatise on the Diseases Produced By Onanism…
“ When the young person is disturbed suddenly, his hands, if he has not had time to remove them, will be found on or near the genital organs. The penis, also, may be found in a state of erection; or you may even find marks of recent pollution, which might be known by the peculiar odor arising from the semen, and which comes from the soiled fingers. Have an eye to those young persons, whose hands, when in bed, or during sleep, are in the position described: they are onanists, or will become so. The same is true in those who frequently have erections of the penis. ”
