DEMENTIA. In Medical Jurisprudence.
That form of insanity which is characterized by mental weakness and decrepitude, and by total inability to reason correctly or incor rectly.
Memory is last ; language is incoherent; actions are inconsistent. The thoughts succeed one another without any obvious band of association. Delusions, if they exist, are transitory, and leave no permanent impression: and for everything recent the memory is exceedingly weak. In mania, the action of the mind is marked by force, hurry, and intensity ; in dementia, by slowness and weakness. It is the natural termination of many forms of insanity. Occasionally it occurs in an acute form in young subjects ; and here only it is curable. In old men, in whom it often occurs, it is called senile dementia, and It indicates the breaking down of the mental powers in advance of the bodily decay. Here we may find memory of conditions long since past and some mental power. It is this form of dementia only which gives rise to litigation ; for in the others the incompetency is too patent to admit of question. It cannot be described by any positive characters, because it differs in the different stages of its prog ress, varying from simple lapse of memory to com plete inability to recognize parsons or things. And it must be borne in mind that often the mental in firmity is not so serious as might be supposed at first sight. Many an old man who seems to be scarcely conscious of what is passing around him, and is guilty of frequent breaches of decorum, needs only to have his attention aroused to a matter In Which he is deeply interested, to show no lack of vigor or acuteness. In other wards, the mind may be damaged superficially (to use a figure), while it may be sound at the care. And therefore it is that one may be quite oblivious of names and dates, while comprehending perfectly well his relations to others and the interests in which he was concerned. It follows that the impressions made upon casual or Ignorant observers in regard to the mental condition are of far less value than those made upon persons who have been well acquainted with his habits and have bad occasion to test the vigor of his faculties.
Senile dementia or the imbecility caused by the decay of old age is often the ground which the wills of old men are contested, and the conflicting testimony of observers, the proofs of foreign influence, and the in dications of mental capacity all combine to render it no easy task to arrive at a satis factory conclusion. The only general rule of much practical value is that competency must be always measured, not by any fan cied standard of intellect, but solely by the requirements of the act in question. A small and familiar matter would require less men tal power than one complicated, in its details and somewhat new to the testator's expe rience. Less capacity would be necessary to distribute an estate between a wife and child than between a multitude of relatives with unequal claims upon his bounty. Such is the principle; and the ends of justice cannot be better served than by its correct and faithful application. Of course, there will always be more or less difficulty; but generally by discarding all legal and meta physical subtleties and following the leading of common sense, it will be satisfactorily surmounted.
The legal principles by which the courts are governed are not essentially different whether the mental incapacity proceed from dementia or mania. If the will coincides with the previously expressed wishes of the testator, if it recognizes the claims of those who stood in near relation to him, if it shows no indication of undue influence,—if, in short, it is a rational act rationally done, —it will be established though there may have been considerable impairment of mind. 2 Phill. Eccl. 449; Harrison v. Rowan, 3 Wash. C. C. 580, Fed. Cas. No. 6,141; Den nett v. Dennett, 44 N. H. 531, 84 Am. Dec. 97; Taylor v. Pegram, 151 111. 106, 37 N. E. 837; Blough v. Parry, 144 Ind. 463, 40 N. E. 70, 43 N. E. 560 ; Fluck v. Rea, 51 N. J. Eq. 233, 27 Atl. 636 ; Matter of Jones, 5 Misc. 199, 25 N. Y. Supp. 109; Matter of Pike's Will, 83 Hun 327, 31 N. Y. Supp. 689 ; Tay lor v. Trich, 165 Pa. 586, 30 Atl. 1053, 44 Am. St. Rep. 679.