Normal brains for histologic study are, in the nature of things, hard to obtain. In the first place, it is difficult to come to agreement on what constitutes a normal brain. Secondly, as Southard has insisted, the cells of a normal brain may purvey abnormal activities. Thirdly, of course, normal persons with supposedly normal brains for the most part live on through adult life.
The brains that have been perforce used are from general or special hospitals (cancer, tuberculosis or lying-in) or from accident cases, which latter are probably as near as possible to the ideal, only the previous habits of the individual fatally injured fade from the minds of interested persons, so that details remain obscure; but a brain from a young adult not insane, feebleminded or criminal, non-alcoholic, nonsyphilitic or tuberculous, not the victim of chronic lead poisoning, electricity, acute or chronic infections, high terminal temperatures, who