CHAPTER VIII.

MENTAL EXCITEMENTS DISTINGUISHED AS PARTIAL

OR GENERAL.

"Behold from far a breaking cloud appears,

Which in it many winged warriors bears :

Their glory shoots upon my aking sense:

Thou, stronger, may'st endure the flood of light."-Dryden.

In the earlier chapters of this part of the dissertation, some examples were adduced of spectral illusions, in which I had merely occasion to treat of ideas, and the excitements to which they alone may be subject from morbific agents. Little or no notice was taken of the important fact, that, in some instances, both actual impressions, and renovated feelings or ideas, may be simultaneously rendered unduly intense. I shall therefore now observe, that, in certain cases of phantasms originating from disease, it is evident that an exciting action is exclusively confined to the vivifying of renovated feelings. And, again, in that more complete illusion which is named an ecstacy, it is no less evident, that sensations as well as ideas are affected; the spectral illusions incidental to this state being far more vivid than when ideas are exclusively excited, and never failing to be accompanied

with intense actual impressions,—such as acuteness of touch, and intolerance of light or sound.

To what causes this diversity of action is chiefly owing it is difficult to say. The nerves connected with the production of sensations are never excited but when the organ which they supply comes in actual contact with external matter. On the other hand, the nerves which give rise to ideas do not impart their peculiar influence, unless excited by that ultimate law of the mind, which ordains, that the repetition of a definite sensation shall be followed by a renovation of the past feelings with which it was before associated. If, then, the nerves, which are considered as instrumental to actual impressions or sensations, derive their origin from the external surface of the organ which they supply, and then influence the circulation, various morbid phenomena connected with the state of the memory no less indicate, that to other nerves, the peculiar function of which is the renovation of past feelings, a different origin may with some reason be assignable; that such nerves may first rise from the brain, and be afterwards distributed to each vascular organ. On this hypothesis may be probably explained the curious fact, that in certain morbid affections, the peculiar seat of which is in the brain, ideas only are excited; and hence, that spectral impressions may be unattended by any such increased sensibility of touch, hearing, vision, &c., as is common to ecstatic illusions.

But i may be now asked, Under what circumstances are sensations and ideas conjointly affected by morbific excitements? In attempting an answer to

this question, it is rather difficult to conceive of a cause which, by acting immediately on the whole of the nervous system, can simultaneously vivify both actual and renovated impressions; but it is not so difficult to conceive of an agent, such as the nitrous oxide, which can communicate a general influence to each organ of feeling through the medium of the circulating system, upon the varied condition of which the vividness of sensations and ideas has a more direct dependence. By this means, therefore, an adventitious or morbific agent can prove the substitute for a general nervous influence; and whenever the blood is in this state of excitement, the phenomena of various ecstacies indicate, that while sensations and ideas are severally increased in intensity, the influence upon which the renovation of past feelings depends, is in proportion more freely and forcibly communicated than that which is connected with actual impressions.

There are, again, other circumstances to be considered in the vivifying actions of morbific causes. *A true ecstacy, which is characterized by the simultaneous excitement of sensations and ideas, is often persistent. But when ideas are exclusively vivified, the action is seldom continued for a long time without remission. Thus, in a case of delirium tremens, which came under my notice, the intense revivals of past feelings of touch, or the distinct tones of voice which vibrated in the morbid ear, "like no mortal sounds," or the

"Forms without bodies, and impassive air,"

that flitted before the sight, were not uninterruptedly

continued, as during an ecstacy, but impressed the senses with evident remissions. The patient had therefore an opportunity of comparing his phantasies with the place in which he was stationed, and with the objects around him, so as to obviate the force of his illusion by the faculty of judgment. Nicolai possessed the same self-collection. "I was always able," he observes," to distinguish, with the greatest precision, phantasms from phenomena. I knew extremely well, when it only appeared to me that the door was opened and a phantom entered, and when the door really was opened and any person came in.” In many instances, however, the illusion has not been so easily corrected.

Nor do causes which exclusively vivify the recollected images of the mind constantly occupy the entire surface of any particular organ of feeling. It is in general only a few objects in a renovated landscape which usurp corresponding portions of the seat of vision. A detached figure may hold a place among natural and real objects, partaking with them of a* similar degree of vividness, and hence be mistaken for an actual impression.

Having at length explained the phenomena by which partial and general excitements are distinguished, I shall, in the ensuing chapters, confine myself to the consideration of those agents which diffuse their influence so generally throughout the system as to act at one and the same moment of time, though in different proportions, both on sensations and ideas, producing what are named ecstatic illusions.

CHAPTER IX.

GENERAL MENTAL EXCITEMENTS CONSIDERED AS THE

RESULT OF MORBIFIC CAUSES CO-OPERATING WITH MORAL AGENTS.

"For I am sick, and capable of fears.”

King John.

I HAD occasion to remark in a preceding chapter, that feelings of pleasure and pain acknowledge certain innate laws, which may be regarded as arising from the particular constitution of the human frame. Thus, it is implanted in our nature, that certain external objects, as of touch, sound, colour, taste, smell, &c. should communicate to every individual definite pleasurable or painful effects.

The particular susceptibility of feeling, however, possessed by each part of the body, may materially differ in degree; and this difference may result from the extent of influence imparted by the brain and nerves to the various organs of sense, or it may arise from some particular condition of the organs themselves, by which the mental effect resulting from the nervous system is more or less modified. Nay, more— such various susceptibilities of feeling may even be occasioned by some unknown peculiarity of the im