which regulate the manifestations of normal activity. There are latent and silent stimulations which, by reason of certain conditions which have presided over their impression upon the organism, remain more vivid than others, and which, by virtually becoming incessantlyactive stimuli, produce a discharge of nervous force, either in the form of interrupted convulsive currents, in that of continuous motor currents (cataleptic condition of the muscles), or in that of sympathetic reactions from the side of vegetative life (vomiting, etc.).

In other circumstances, we have no longer to deal with an isolated phenomenon, revealing itself by definite manifestations, and reflecting as before the deviations of a normal process regularly accomplished. We observe, in fact, manifestations of quite a different kind, which reveal themselves by a species of exaltation of the psycho-intellectual regions, which preserve and store up external impressions in a very vivid manner, and when the cerebral elements have risen above their usual pitch, manifest their new condition by an unexpected superactivity quite contrary to the habits of cerebral life of the individual.

We see patients, indeed, gifted with very ordinary intelligence, who, when in this phase of cerebral erethism, will improvise, make quotations, associate new ideas with extreme rapidity, say witty things and make punsthings they are quite incapable of doing when in their ordinary vital condition.

Michéa cites the case of a young butcher whom he observed in the Bicêtre, and who, under the influence of an attack of mania, recited whole speeches from the Phèdre of Racine. During an interval of calm, he said he had

but once heard the tragedy in question, and that, spite of all his efforts, he could not recite a single verse.

Van Swieten cites from the same author the case of a young workman, who, never having dreamed of making verses, during an attack of fever became a poet and inspired. Perfect speaks of a lunatic, who, during his delirium, expressed himself in very harmonious English verse, although previously he had never shown any disposition for poetry. Tasso is said to have worked better during an attack of mania, than in his lucid intervals.*

Finally, in other circumstances we observe phenomena of an entirely inverse character. Far from being phenomena of over-excitement of the memory, they are those of dislocation and clouding over.

Persons thus affected, more or less completely lose the faculty of retaining certain memories; either through the destruction of certain circumscribed regions in the cortical substance,† or through the progressive destruction of its elements.

Similarly there are certain persons with dementia who, being affected with partial amnesia, forget the date of the day and year in which they live; they do not know their way, lose themselves in the streets, and yet they are still able to sustain a certain amount of current conversation. Others, on rising from table forget they have had their dinner, and order it to be served up. Others, after receiving a visit from their relations or friends, and

• Michéa, "Annales Médico-psychol.," 1860, p. 302.

Voisin has pointed out a case of amnesia with softening of the cerebral substance. The patient had lost the memory of objects, and had forgotten names and substantives. If a spoon were presented to him he could not tell the name of it, but showed by his gestures that it was for eating soup with. ("Sociétié Anatomique," 1867, p. 342.)

conversing with them, when the visit is fairly over-an hour afterwards-retain no definite impression about it, or else make mistakes; when, for instance, they have received a visit from their daughter, they will say they have had one from their grandfather, etc.

There are others again who, although enjoying a certain portion of their faculties and the capacity for speaking regularly, lose little by little the memory of proper names, then that of substantives, then of verbs, and make mistakes in orthography. Cuvier, in his lectures, mentions the case of a man who had lost the memory of substantives, and who could form sentences very well, with the exception of names, which he left blank.*

It is curious to remark, as J. Falret has done, that in this process of decay which takes place, the human mind in despoiling itself of its wealth, loses it chronologically in the order in which it has accumulated it. Thus it is the remembrance of proper names which is first extinguished; these, as we have previously remarked, p. 161, representing the first periods of the work of the intelligence in ascending evolution. Then come common names, adjectives and verbs, which represent a more advanced degree of the perfectionment of the faculties, when the child has begun to express his will by means of appropriate verbs.

Thus in these periods of progressive decadence the processes of memory being gradually deprived of the materials by means of which they effect their manifestations, cease to be regularly evolved; amnesia advances further and further, and we see individuals thus affected 'Annales Médico-psychol.," 1852, p. 395.

quite incapable of registering present impressions, preserving no remembrance of what passes around them, forgetting the past, and becoming more and more incapable of expressing their sentiments and wishes, in consequence of the progressive wearing out of the organic apparatuses that serve for the evolution of the processes of memory.

BOOK III.

AUTOMATIC ACTIVITY OF THE NERVOUS

ELEMENTS.

CHAPTER I.

INTRODUCTORY.

THE automatic activity of the nervous elements, like their histological sensibility, is merely one of the special forms of their peculiar vitality.

Diffused, in a similar manner, in its most simple forms, through the most elementary organisms, this automatic activity is perfected, and amplified, in proportion as it is distributed through more abundant and more dense agglomerations of cells, which are at the same time endowed with a more intense vital energy.

It reveals itself in its most simple forms, as a histologic property of the free cells, the white corpuscles of the blood; of that series of cells with mobile prolongations (vibratile cilia, spermatozoids), whose automatic energy is manifested in such characteristic amoeboid movements; and finally of isolated masses of protoplasm.

As we ascend in the zoological series, we perceive that the manifestations of automatic life consist not merely in purely local phenomena, in which the histologic ele