300 INSANITY stroke, and tumors in the brain. Acute febrile diseases, as typhoid, typhus, and malarial fe- vers, are also causes of insanity ; and it may oc- cur during the course of pneumonia, general- ly in the form of acute mania. The poison of Asiatic cholera may so interfere with the nutrition of the brain as to produce not only transient delirium, but mania, which may con- tinue for several days or weeks. Acute rheu- matism is sometimes a cause of insanity ; and it is an interesting fact that the mental symp- toms follow the apparent disappearance of the rheumatic symptoms, and pass away upon the reappearance of the disease. Chronic con- stitutional diseases are frequent causes, and among the most formidable probably of these is constitutional syphilis. Its effects are pro- duced in a variety of ways. The skull may be the seat of exostosis or of caries ; the mem- branes may be affected and cause mal-nutrition of the cerebral substance ; or tumors of the brain may arise directly from the effects of the syphilitic poison ; or the nutrition of the whole body may be so interfered with that all the plastic material furnished by the food is viti- ated and incapable of forming sound nervous tissue. The syphilitic affections of the nervous system have recently been the subject of careful examination by Drs. Wilks and Moxon. Ac- cording to Dr. Wilks, there is in syphilis a dis- position to a low form of lymph in nearly every tissue of the body, which does not readi- ly form tissue, never that which is perfectly normal. According to Dr. Moxon, syphilis at- tacks the surface of the brain and its mem- branes in limited spots, spreading slowly. The lymph which exudes from the membranes de- stroys the gray matter of the convolutions, and syphilitic deposits may form fleshy tumors which contain a certain gummy characteristic substance ; or the brain and spinal cord may be invaded by gummatous tumors springing from the dura mater or the bones. Paralysis of various degrees of intensity and extent, and also mental diseases, are the results. (See lec- tures of Dr. Broadbent, "London Lancet," 1874; also an illustrative case, with plates of pathological changes, " American Journal of Insanity," July, 1874.) Tuberculosis, particu- larly by inducing a state of exhaustion or de- generated tissue development, is sometimes an exciting cause of mental disease ; and, as will be noticed further on, there are apparently intimate relations between tuberculosis and insanity and certain other forms of nervous disease. Diseases of the heart have been as- signed as causes of insanity, and as far as they operate in exhausting the strength of the patient, they may be considered as such ; but more often the heart disease is, along with the mental affection itself, the effect of other changes, such as disease of the arteries or capillaries, or of the vaso-motor system of nerves. Disease of the genital organs some- times exerts an important influence in produ- cing insanity. During the period of sexual de- velopment, particularly when any morbid con- dition is present, resulting from secret vice or from any cause, insanity in some form, mania, melancholia, or dementia, is liable to occur. Disorders of menstruation at any period of life may bring on attacks of mental disease ; as also may diseases of the uterus or ovaries, such as tumors, cysts, or displacements. Pregnancy, the puerperal state, and lactation are not infre- quent causes of mania and melancholia. A state of melancholy during pregnancy is often the precursor of an attack of puerperal mania. Insanity from lactation is generally in conse- quence of the exhaustive effect of the function superinduced upon a hereditary predisposition. Sexual excess and unnatural vice, from indu- cing a perverted condition of the mind and ner- vous system, as well as from their weakening effects, are not uncommon exciting causes of insanity. But among all the causes of mental disease, it is acknowledged by most authorities that the excessive use of intoxicating drinks is the greatest. Of 1,428 cases admitted into Bethlem hospital, 12 per cent, were found to be caused by intemperance. The report of the commissioners in lunacy in England in 1844 gives, out of 9,868 cases, 1,792, or more than 18 per cent., as the proportion attributable to the effects of alcoholic liquors. Of 748 cases, Halloran found drunkenness a cause in more than one fifth. Prichard and Esquirol attribute half of the cases of insanity in England to in- temperance. Dr. Rush gave it as the cause in one third of the cases in America, and more recent statistics of some asylums show a larger proportion. Blandford and other modern wri- ters ascribe to it a potent influence. Dr. Dick- son, late superintendent of St. Luke's hospital, London, takes a somewhat different though not opposite view. He says : " Although it is true that drunkenness is very frequently the exciting cause of an attack of insanity, yet the incen- tive to drunkenness is the result rather than the cause of brain deterioration in the first in- stance ; a potentiality of insanity is often dis- covered on examining the history of the persons who complain of a constant sense of depres- sion, and who seek to relieve that depression with stimulants." The continued use of intox- icating drinks and narcotic poisons, in the opinion of Dr. Carpenter ("Mental Physiolo- gy," 1874), destroys or weakens the will so that it loses its control over the emotions. The experiences given by De Quincey as to the weakening of the will in his own case, so that he became unable to perform what he had planned, not from want of brain power, but of volition, is instanced by Dr. Carpenter as an example ; and he also points to the exces- sive use of tobacco in creating a mental state which manifests itself in deferring the per- formance of pressing duties. The effect of alcohol he regards as more potent in weak- ening the will and arousing the more violent passions than that of any other agent ; and it is not improbable that the excessive and habit-
