seems to think that insanity is on the increase, and those who are of opinion that it is not, account for the apparent increase by the fact that in the more thorough and wide-spread diffusion of medical knowledge many diseases are now recognised as insanity which were not formerly regarded as belonging to that class of disease. When a man makes a will and dies his relations who are not mentioned in it may dispute its validity. Was the individual, at the time he made his will, in such a mental condition as to possess a testamentary capacity? In such a case the Court of Probate will have recourse to the evidence of medical witnesses. When a man or woman contracts a marriage which is regarded by his or her friends as unaccountable, or which may, by the issue from it, deprive the said friends of a contingent reversion, the question as to whether the person contracting was sane or insane at the time, whether he or she could or could not give a valid consent-consent being the essence of a contract*—will arise, and the evidence of medical witnesses will be required. So if a man squanders his money or commits a crime, the evidence of physicians will be requisite to determine the fact of his sanity or insanity. Besides, there are cases in which insanity is feigned, and it is necessary that medical men should be able to distinguish between the genuine and the simulated. Now, too, no insane person can be incarcerated in a lunatic asylum without the certificates of one or two medical men.† In all these cases it is necessary that the individual physician who is called. upon to ascertain the mental condition of another individual should have a somewhat thorough knowledge of insanity, and all thoroughness and clearness is to be best attained by careful classification.

Mental diseases may, then, be divided into two classes-1st, into those which are dependent upon arrested development or diminished activity of the faculties; and, 2nd, those which are due to some functional derangement or organic lesion in the brain or the nervous centres subsequent to what may be regarded as normal development. The former is marked by defective energy or inertness of mind, the latter by undue activity and excitement of the mental faculties. Perhaps the best practical classification of mental diseases for the purposes of those who would become acquainted with them in connection with the legal relations of those who labour under them is that which is given below. It is somewhat the same, in its main features, as that adopted by Esquirol. * 1 Powell, contr., pp. 9 and 10. See Hardman v. Booth, 1 H. and C., pp. 803, 807.

16 & 17 Vict., c. 96, ss. 4, 7.

We may add another classification of mental diseases which has found some favour in the eyes of the medical profession. We need not point out its errors, which are obvious.

Class I.-Insanity resulting from

arrested or impaired de

velopment of the brain.

Class II. Idiophrenic Insanity.

Class III. Sympathetic Insanity.

Idiocy, congenital and acquired.

(1) Sthenic and asthenic idiopathic insanity.

(2) Phrenic insanity (inflammatory).

(3) General paresis.

(4) Paralysis with insanity.

(5) Traumatic insanity.

(6) Epileptic insanity.
Epileptic insanity.

Insanity of masturbation.

Insanity of pubescence.
Climacteric insanity.

Ovarian and uterine insanity.

Insanity of pregnancy.

Puerperal insanity.

Class VII.

Metastatic Insanity.

Insanity from opium-eating.

Rheumatic.

Pellagrous.

Metastatic insanity from healing of longestablished issues.

Note.-Professor Laycock's "Nosological Index," first published in his work on Medical Observation and Research,' 2nd edit. p. 342, although eminently suggestive, is of too complex and theoretical a character to be available for practical purposes.

In the first of these methods the mental peculiarities of the patient are the ground of classification; in the latter the mental symptoms are put aside and disregarded, and the forms of disease are classified according to their supposed pathological causes and the relation of these causes to the bodily organism.

No classification is perfect. We must endeavour to obtain that which will be most useful to those who would treat disease, and to those who would understand in what cases mental aberration or defect will modify the relations of an individual to his fellow-countrymen, to his property, and to the state. The classification quoted above which is based upon the pathological cause of the disorder has a look of science about it which will deceive many. It is a fact proved by the everyday experience of those who have to do with mental disease that we find many patients whose insanity, although resulting from exactly similar causes, differs the one from the other in every possible particular. Besides, is it not evident that, to arrive at any conclusion with regard to the cause, we must take into consideration the mental peculiarities of the patient, and thus rise to the classification which pretends to be independent of mental symptoms, through the very classification of peculiarities of mental condition which it pretends to discard? In the above classification it is obvious that there are grave mistakes which present themselves even to those who are only partially acquainted with nosology. Thus, to place Idiopathic Insanity as a sub-class under Idiophrenic Insanity shows how weak the system is. A classification which is understood to be framed according to pathological causes has taken care to have a class where all maladies which cannot be thus classified are to be placed. How large this class is it is impossible to say, but any classification which has under it a class which it is impossible to classify seems to us as satisfactory in its way as an argument which demands the conclusion as a datum. Again, under Class 3, Sympathetic Insanity, we find the sub-classes Climacteric Insanity and Post-connubial Insanity. To pretend to classify diseases according to their pathological causes, and then to state as a cause a whole system of life, or a bodily condition existing for years, is surely unphilosophical. It would be as correct to give as a sub-class "insanity arising from previous conduct." But the errors are too many to allow us to do them the justice of pointing them out, and too obvious to require it.

Upon the whole, consideration induces us to adopt the first of

these two classifications. It is certainly of the utmost importance that a classification should be adopted for the purposes of medical jurists which is easily understood, and the ground of which is to be found in easily observed symptoms. Only in this way will the great gulf which separates medical men and lawyers be bridged over. When, however, mental peculiarities, as inferred from conduct, are taken as the basis of the methodical arrangement of kinds of insanity, or of patients labouring under them, into certain groups, little difficulty is likely to arise; as to a lawyer, insanity is to be inferred from certain acts, not from the existence of a certain cause. It must be remembered that all classifications are defective, and can only be defended on the ground of convenience and expediency, not upon that of absolute correctness or truth. In many cases much difficulty will be found in assigning some mental disorder to any one of the classes above enumerated, and care must always be taken to appreciate the fact that these words are not absolute partitions between diseases. In many cases these peculiarities which have served as a distinguishing feature of one class are found mixed with, or modified by those which have served as the distinguishing features of another. A classification is like a walking-stick, a thing to be of assistance. Yet some children ride on a walking-stick and some men make a hobby of a classification. It is mental weakness which is the cause in each case.