affect their pecuniary interests, but their whole future happiness and comfort. When, however, the mental deficiency has not been sufficient to provoke interdiction, though plain enough to be generally recognised, it, very properly, constitutes no legal impediment to marriage, but on proof of fraud or circumvention the marriage has been pronounced by the courts, null and void.1 It is obvious that no general rule can be applied to all such cases, for while marriage might conduce to the interests of each party in one case; in another, it might be equally ruinous to the interests of one or both partic:-.. Every case should be judged on its own merits, and only annulled when the mind of either party is proved to have been operated on by improper influences.

CHAPTER V.

PATHOLOGY AND SYMPTOMS OF MANIA.

§ 86. While medical literature is far from being deficient in works on Insanity considered as one of the most serious maladies to which man is liable, the popular notions respecting it are peculiarly loose and incorrect. As these, however, are the source of many of the faults in the jurisprudence relating to this affection, it is necessary to enter somewhat into its medical history, and to discuss points which might seem, at first sight, to be of an exclusively professional nature, but a proper understanding of which is absolutely necessary to save us from gross mistakes on this subject. Certainly no greater absurdity can be imagined than that of fixing the legal relations of persons in a particular state of mind, while entertaining the most imperfect notions of what that state really is,—unless it may be that of pertinaciously clinging to those notions and discouraging every attempt to correct them, after the progress of scientific knowledge has shown them to be erroneous. Before describing the phenomena of mania, it should be distinctly understood that it is, first, a disease of the brain; and secondly, that in its various grades and forms, it observes the same laws as diseases of other organs. The importance of these propositions makes it proper to state the grounds on which they rest; for until they are clearly recognised and appreciated, it will be in vain to expect any improvements in the medical jurisprudence of insanity.

§ 87. I. Mania arises from a morbid affection of the brain. The progress of pathological anatomy during the present century, has established this fact beyond the reach of a reasonable doubt. It can hardly be necessary at the present time, to prove the fact of the dependence of the mind on the brain for its external manifestations—that, in short, the brain is the material organ of the intellectual and affective powers. Whatever opinion may be entertained of the nature of the mind, it is generally admitted—at least by all enlightened physiologists— that it must of necessity be put in connexion with matter, and that the brain is the part of the body by means of which this connexion is effected. Little as we know beyond this single fact, it is enough to warrant the inference that derangement of the structure, or of the vital actions of the brain, must be followed by abnormal manifestations of the mind; and consequently, that the presence of the effect indicates the existence of the cause. If it be an organic law, that derangement of structure is followed and indicated by derangement of function, it cannot for an instant be doubted that insanity is the result of cerebral derangement, since the manifestation of the mind may be considered as one of the functions of the brain. Whether the morbid action arises in the digestive, or some other system, and is reflected thence to the brain by means of the nervous sympathies, or arises primarily in the brain, the soundness of the above principle is equally un

touched. This leads us to the source of the hesitation that has been evinced by pathologists to consider the brain as the seat of insanity.

§ 88. From the fact that organic lesions are not always discoverable after death in the brains of the subjects of insanity, it has been inferred that the brain is not the seat of this disease ; though, if this fact were true—it being also true that no other organ in the body invariably presents marks of organic derangement in insanity—the only legitimate inference would have been, that, in some cases, it is impossible to discover such lesions by any means in our power. Besides, if insanity is produced by some obscure affection of the nervous influence, or vital principle, as has been seriously imagined, with what consistency could the believers in this speculation look for change of structure any where? But the strangest theoretical error which this apparent soundness of the brain in some cases, has occasioned, is that of denying the existence of any material affection at all, and attributing the disease entirely to an affection of the immaterial principle. If the same pathological principles had guided men's reasoning respecting this disease, that they have applied to the investigation of others, these errors would never have been committed. It will scarcely be contended, at the present day at least, that the structural changes, found after death from any disease, are the primary cause of the disturbances manifested by symptoms during life; or that if the interior could be inspected at the beginning of the disease, an)' of these structural changes would be discovered. It is now a well-recognised principle, that such changes must be preceded by some change in the vital actions of the part where they occur. This vital change is now generally expressed by the term irritation, and nothing is implied by it relative to the nature of this change, more than an exaltation of action. Irritation then is the initial stage of disease,—the first in the chain of events, of which disorganization is the last—and, of course, nothing can be more unphilosophical than to attribute disturbances of function, exclusively to any structural changes that may take place during the progress of these successive stages. The departure from the normal course of vital action, which is probably as unexceptionable a definition of irritation as can be given, is sufficient to derange the functions of the part in which it occurs, without producing any visible change in its appearance; and hence, we may oftentimes explore the dead body with the utmost minuteness and skill, without being enabled to infer from any thing we find, an adequate cause of death. Before this can be found, the initial stage must have continued more or less time; and though it always tends to pass into the subsequent stages, yet death may take place from various causes, before they are developed and before a trace of their existence can be detected.

§ 89. There is this peculiarity in the pathology of insanity, that while the irritation deranges the mental functions so as to be manifest to every observer, its sympathetic effects upon the rest of the system are so slight that they contribute but little comparatively, by their reaction, to develope the stage of inflammation. The consequence is, that cerebral irritation, sufficient to produce insanity, may endure for