The disorder commonly called “general paralysis of the insane” presents so many points of interest to the pathologist and the physician, that as a necessary consequence it forms the commonest topic among the writings of those who specially study insanity. But after so much observation and so many treatises, it is disheartening to find that even now scarcely more than one fact with regard to it is laid down as settled and established beyond the possibility of doubt. One there is, the saddest that can be. It is, that for this malady we hitherto have found no cure; that to diagnose it is to pronounce the sentence, not only of incurable insanity, but also of speedy death. The marvel of the whole is, that although death occurs in every case at no very distant period, though postmortem examinations of general paralytics are made by hundreds every year in this and other countries, yet even at this day no two observers are agreed as to the pathology and morbid anatomy, as to the part in which it has its origin, or which constitutes its peculiar and proper seat. No wonder that the whole of the morbid anatomy of insane brain is vague and ill-defined, when this, the specially fatal form of mental disease, still hides itself from usâ still wraps itself in the mystery which envelopes all that relates to mind. I make no apology for drawing the attention of the readers of this Journal to a paper on the subject, published in the October and November numbers of ‘ Virchow's Archives/ 1865, and for giving a short and necessarily imperfect summary of its contents, it being too long for reproduction. But as every outline must needs be unsatisfactory, I trust my readers will go themselves to the original. In default of opportunity of examining many brains of paralytic patients, I present as a contribution to the English treatises on the subject these observations of another.