more reliable the statistics, the less liable are they to underestimate the proportion, and it is highly probable that their accuracy has been increasing with each decade. Any probable error, in any case, would be in favor of a better proportion, and of fewer insane. Another point to be considered is that with modern philanthropic methods and appliances the death-rate of the insane decreases, and the actual number alive and under care is increased. The proper method of estimating the actual increase would be not to take the actual proportion, but the number of new cases occurring each year, and this would probably give us somewhat better figures. There is little question, however, of the actuality of a certain steady increase up to a point where the equilibrium between cause and effect is established, and this is the more difficult under the conditions of change and stress of modern life.

Still another consideration is due in any American estimate of the increase of lunacy: it is that of the disturbing factor of immigration. This alone is enough to disturb the natural equilibrium to such a degree as to make statistics hardly an exponent of the real condition of things. In some parts of our country half or more of the insane under public care are foreign born, and while this is the case it cannot be said that the conditions are equivalent or parallel to those existing in an old and long-settled community, like some of the European nations, whose figures are available and are often utilized for comparison. The problem is a complex one, and the most we can say is that there is no question but that insanity is increasing to some extent in civilized nations, and those coming under the influence of civilization. The reasons for this fact and the exact ratio of increase are as yet unsettled questions.

CHAPTER II.

ETIOLOGY.

IN considering the etiology of insanity one fact is predominant, that in the vast majority of cases, whatever be its immediate exciting cause, it is more remotely the result of a predisposition or favoring weakness, without which the direct and obvious cause would have been ineffective. This predisposition is found when sought in nearly every case, and when not found may often be inferred from the inadequacy of the apparent factors in the causation of the mental disorder. As Spitzka remarks, the sane are equally liable to the exciting causes of insanity, which are ineffective in them; it is only those that are especially vulnerable that suffer from such influences.

Heredity. First among all predisposing factors of insanity must be reckoned heredity, or the hereditary transmission of a liability to mental breakdown or failure. It has been said in courts of law by prominent alienists that there is no such thing as hereditary insanity, but such an assertion is far less justifiable in this case than in that of many other disorders. Insanity as a result of imperfections of brain structures that are transmissible may be directly hereditary. It may appear at the same period of life in parent and child, and may even, as in the case of suicidal impulses, be photographically similar in type as well as chronologically equivalent. In certain extreme forms, such as idiocy and imbecility and original paranoia, the derangement is congenital, and it is in these especially that heredity is often the most manifest.

The part played by heredity has been somewhat

differently estimated by different authorities, largely on account of special views held as to what heredity is, and in part also owing to the use and dependence upon imperfect statistics. A family history of insanity is often concealed, and in the poorer classes, who largely fill the asylums from which the statistics are obtained, there is a very general lack of data in this regard. This fact is noted by some of the earlier writers, notably by Esquirol, and alienists generally recognize this possibility of error, though they may differ in their estimate of its importance. Confining the heredity to that of mental disorder, however, some of the latest statistics* give a percentage of from 30 to 35 in which there is a family record of direct or collateral heredity of insanity, which figure is undoubtedly rather under than above the truth. can probably say that nearly 40%, at least, of the insane have some family history of mental disease, could all the facts be known. If recent theories of heredity are accepted,-that of Galton, for example,ancestral defects may be manifested even in the fourth generation, and there are comparatively few who are able to trace their family record back to their great grandparents, as regards mental health or disease; there are few, therefore, who can give a clean bill of health in this regard. If the range of inquiry is extended to cover eccentricity or neurotic manifestations of one kind or the other, the probabilities of finding defects are vastly increased.

We

There is, however, as is well known, no fatal certainty of the transmission of mental or other defect; the children of insane parents may escape altogether, or it may appear in only one or two members of a family, or may skip one or two generations. Insanity, however, is as little liable to these examples as other disorders, and, in fact, it may be considered as one * W. C. Krauss: "Medicine," Nov., 1897.

of the most hereditary of diseases, bearing in mind, at the same time, that the insanity of the parent is no insurance of that of the child, and that if it has occurred after the birth of the latter, there is a better chance of its escape. In that case the offspring inherits only the general weakness that caused the breakdown of the parent, not the added injury to the brain from the parental insanity itself.

Of the two parents, the mother is, according to the almost universal authority of alienists, the one whose insanity is most liable to be transmitted to the child. According to some authors, this maternal transmission is twice as frequent as that from the father, and the severer types of insanity are more likely to be thus inherited. Dagonet* suggests that as the mental development of the female predisposes her more to the essential or simple types of mental alienation than does that of the male, this fact may serve to account for the predominance of female heredity.

If besides the heredity of mental disease itself we take account of other neurotic and degenerative conditions, we greatly enlarge the scope of hereditary influence in the causation of insanity. Eccentricity, epilepsy, hysteria, "nervousness," intemperance, vagabondage, and criminality, as well as various organic and functional (so-called) neurotic disorders, are very often met with in the family histories of the insane, and there are certain disorders, the liability to which is inherited, that may alternate in the generations with mental disorder; among these may be named tuberculosis, and especially gout, and what the French call the arthritic diathesis, which is often a manifestation of a liability to neuroses of various kinds, insanity being included amongst their number. These conditions do not necessarily imply their being followed by insanity, for the reverse is generally the case, but * "Maladies Mentales," Paris, 1894.

P. 120.

they are sufficiently often its antecedent as to show a probable connection between them.

Alcoholism of parents is, on the other hand, so common an element in the family history of the mentally defective or deranged as to be justly counted as a predisposing cause, and one of the most important. It is especially manifest in the causes of idiocy, imbecility, and epileptic insanity, a very large proportion of the victims of these afflictions having a history of parental intemperance. The habit of drinking is, in a sense of the term, itself inheritable; the children of drunkards are often themselves more liable to become drunkards. These are matters of common popular belief, but they have also the authority of the experience of alienists and the medical profession. If intemperance were as common in the female as in the male sex, it would, as a cause of insanity, be much more important than it is at present.

Bourneville* found amongst 1000 idiots admitted to the Bicêtre in the decennium 1880 to 1890, alcoholism on the paternal side in 471; on the maternal side in 84; and on both paternal and maternal sides in 65. It was denied in 209, and facts were not obtained in 171. In 57 cases it was learned that conception occurred. during paternal intoxication, and this was probably the case in 24 more.

Hysteria, epilepsy, and other neuroses in the parent have been already mentioned. It is not infrequently observed that the parents of the insane on one side. or the other are themselves on the borderland of insanity; while not exactly over the boundary-line, they are erratic, peculiar, "nervous," or otherwise manifest a degenerative neurotic tendency. We have in these cases what has been called the insane diathesis; a condition that tends to insanity, if not in the individual himself, at least in his descendants. This is so common

*"Le Progres Med.," 1897. 21.