If the meaning of the word dementia were restricted to the definition at present generally accorded to it, it is certain that the insane comprised in this category would rarely exhibit the phenomena of hallucinations and illusions. But from the stage at which the intellectual faculties begin to fail, to the period of their complete obliteration, the degrees are infinite.

There arc some deranged persons who have but a momentary wandering, and who resume conversation, as if no hiatus had occurred in their minds. With such, the signs of dementia only exhibit themselves at intervals more or less distant. Frequently - and this fact has more particularly engaged our attention - we find in dementia the maniac and monomaniac types, so that we can establish the following classification; monomaniac dementia, maniac dementia, complete dementia, to which must be added senile dementia. This distinction appears to us of sufficient importance to be made hereafter the subject of a special work.

In considering dementia under this new aspect, it will not excite surprise, that our experience differs materially from that of Messrs. Aubanel and Thore. Thus, whilst these physicians encountered only one case of hallucinations, in 45 of dementia; we have observed 16 cases out of 21 in which hallucinations and illusions existed. The combination was as follows: -

Case LXII

Mademoiselle C, seventy-two years of age, did not show any symptoms of derangement of mind until her seventy-first year. At that period, instead of leading a sedentary life, according to her usual habits, she travelled continually. Her family, being unable to persuade her to remain quiet, brought her to my establishment. This lady then fancied that some treacherous person had secured her papers; that she was his victim; that, to wrong her, he had forged her signature; and that his object was to obtain her property. In this accusation she included three other persons. Her discourse was rambling, nor did she recollect what she had said. Her memory was weakened, but she often spoke with clearness. This state lasted for entire days.

On interrogating her, we found that, for several months past, she had seen in the evening, and particularly in the night, persons around her bed, who, besides making noises, held conversations that she did not understand. "When I was in the country," she would say, "I was followed or accompanied by men of consequence, who sometimes disappeared, sometimes rode in cabriolets. I very often met an officer from the castle, who appeared as soon as I got into the street; his mission was to protect me." She replied to all questions so rationally, that the examining magistrates would have been embarrassed if she had not returned to the subject of the traitors, amongst whom she accused several honorable persons. As soon as the magistrates were gone, she assured us that it was a plot, stating that they were disguised, but that she had recognized them.

On some days, this lady, whose recollection of names and persons was so good, and who replied so rationally to all the questions addressed to her, entirely lost her reason. She thought that the king paid her board; that I had created a double, and was not myself; but after a few minutes, she did not recollect what she had said. Amidst her greatest wanderings, she always maintained the idea that she had been conducted to my house by an individual under a false name, and that this imprisonment had no other object than to deprive her of her property.

Mademoiselle G. often spoke in the night to imaginary persons. Sometimes she replied in a friendly or respectful manner; at others, she used insulting language. One morning she assured me that one of the boarders, Madame D., had been to see her in the middle of the night (each one was locked in her own room) to tell her that she was the Goddess of Folly, which was acknowledged throughout the country. Then her ideas changing, she fancied that the portrait of Fate was being painted; that she was Madame Georges, that I ought to let her out to unmask the evil-doers. All this was pronounced in a low and confidential tone, in order to prevent the supposed persons from hearing her.

For two years, the condition of Mademoiselle C. did not alter; she continued to believe herself the victim of treachery, and said that several persons had committed faults for which she was shut up. Almost daily she begged me to allow her to go to church, but her intention was to escape. Whenever she was asked details relative to her business or concerning her acquaintances, she replied correctly, and her memory, although weakened in many points, had great tenacity for the names and characters of those whom she had not seen for many years. This lady died at the age of eighty, having the same hallucinations, without any augmentation of her insanity, and preserving great firmness of character.

There are some persons affected with dementia, who are very little influenced by external impressions; their intermediate ideas are gone; their memory is impaired; but they can, nevertheless, engage in and follow, for the moment, a conversation. A young lady in this condition, was attacked with hallucinations. She thought that her brother, who had been several years deceased, lived in one of the rooms of the establishment; she heard him sigh, and utter lamentations. Convinced that some persons were beating and desirous of killing him, she became agitated, ran from right to left, called him, and uttered cries. At night, she saw people with whom she quarrelled, and who gave her blows; in order to defend herself, and prevent their coming in contact with her, she never undressed. This lady declared that bad smells were spread around her, and that her food was poisoned; she then refused nourishment, ate dry bread, and drank only water.

Very often, on questioning her, she would either not reply at all, or talk incoherently, without any regard to the questions asked.

The monomaniac form of hallucination may continue to a very advanced stage of the disease. Madame M., aged eighty-one, has lost her memory; she no longer recognizes her children; her past and present life is a blank. During the four years that she has passed in the establishment, one hallucination has been her torment. Her husband, who died six years previously, is ever present with her; but he is not above one foot in height; he appears to her as a soul. He wanders on the walls, on the roof, in the street; he calls to her, and complains of cold, because he is naked and hungry. She replies with sighs, shrieks, and howlings; desires to have brandy, soup, and clothes brought. Almost incapable of walking, she endeavors to get to the courtyard, where he tells her to come. Sometimes he shows himself as a head to which wings are attached. We have already spoken of this lady in another chapter.

Dementia often exhibits itself in a maniacal form; and it is sometimes very difficult to discover the shades of difference which separate the two states. A person may appear maniacal who has already advanced one step into dementia; another appears demented, who, as yet, is only maniacal. As the malady progresses, the diagnosis does not long remain doubtful; but the statu quo condition may last a considerable time, and the difficulty is then very great.