drugs, and this is so, whatever the nature of the damage may be-clot, or softening however caused. The statement one occasionally hears (1) that a patient cannot recover from paralysis when part of a motor centre is permanently wanting, and (2) the statement that prompt and complete recovery shews that there "could not be" a destructive lesion, are simply not true. From not knowing that recovery is spontaneous in many cases of hemiplegia from local damage, erroneous conclusions are come to on therapeutics; the patient may get well of this variety of syphilitic hemiplegia, but our drugs do not cure him.

Third variety of Syphilitic Hemiplegia (Hemiplegia after a Convulsion).There is hemiplegia, almost invariably transitory, after a convulsion. This form of hemiplegia (the epileptic hemiplegia of Dr. Todd) is so very indirectly owing to syphilis that the convenience, even for utilitarian purposes, of the expression "Syphilitic Hemiplegia" is very dubious indeed. Syphilis is one of the commonest causes of this variety of hemiplegia. The causation is, however, we shall see, very indirect.

We find post mortem in such cases a gumma in the membranes growing into the convolutions. What happened, I suppose, was that the gumma was first formed. Secondly (as explained under the head of Convulsion), the gumma, as a "foreign body," causes localised instability of grey matter -causes a "discharging lesion." The gumma is syphilitic, but the "discharging lesion" is not, for a similar one is producible by a glioma. Thirdly, the convulsion is a result of a strong discharge of the locally unstable grey matter. Now for the fourth step, which brings us to the symptom spoken of. In some cases the patient is paralysed after the convulsion, that is, when the cerebral discharge is over. According to the degree of the discharge he may be weak of one side or perfectly hemiplegic, even with lateral deviation of the eyes. If, however, the convulsion has been local, the subsequent palsy will be only of the parts first and most convulsed. The paralysis is, I think, a consequence of the discharge-an after effect of a very excessive discharge. The fact that it is in the parts first and most convulsed, that it occurs often in cases where there is no loss nor trouble even of respiration to imply cerebral congestion or extravasation, and that it is transitory, render the inference warrantable, that the paralysis directly depends on exhaustion of nerve fibres in the

corpus striatum,* which "carried" the violent current in the convulsion. I venture on the generalisation that excessive nervous discharges temporarily paralyse the nervous region in which they begin and through which they spread. The importance of this generalisation is in the application of the explanation of epileptic hemiplegia to mania after epileptic paroxysms. We now see that this variety of "Syphilitic Hemiplegia" is a very indirect result of syphilitic disease of the brain. To recapitulate. The order of events is (1) Formation of an overgrowth of connective tissue; (2) Induction of changes of instability in neighbouring grey matter; (3) Occasionally excessive discharge of that grey matter; (4) Temporary exhaustion of nerve fibres in the corpus striatum representing the parts paralysed.

Supposing, however, that my speculation is incorrect, and supposing that the usually acceptedt speculation is correct, viz., that the paralysis after convulsion is due to congestion, or to extravasation of blood, or to both occurring in the paroxysm. The fact, even then, is that the paralysis is very indirectly owing to syphilis, for neither the extravasation nor the congestion are syphilitic changes.

Apart from all kinds of speculation the facts are that there is permanently a gumma in the vertex, only occasional convulsion and only paralysis when the convulsion is over, and that paralysis is temporary. Such cases are not at all un

common.

In cases of this variety of hemiplegia there may be errors as to the effects of drugs. It must never be forgotten that hemiplegia, after a convulsion, due to organic disease of the brain's surface, such as syphilitic gumma or glioma, is nearly always transitory. Unless there be a repetition of the convulsion, the hemiplegia will pass off in a few hours or days, sometimes leaving the side affected a little weak, although not obviously paralysed. So then if the patient took drugs an inexperienced person might suppose that he cured his patient of "Syphilitic Hemiplegia." There are cases in which absolute paralysis after a convulsion will pass

I used to say (Study of Convulsions, St. Andrew's Transactions, 1870) "of the nerve fibres which pass from the part discharged to the muscles convulsed." Really this cannot possibly be the explanation, because there will occur after convulsion absolute, and yet transitory, paralysis of a part, of the arm for example, when there has been no trace of affection of consciousness, and not the least embarrassment of respiration in any part of the convulsion. Moreover, the convulsion has affected most the parts paralysed, a "coincidence" not explainable on the theory here disputed.

off in a few hours.

The most careless man would not suppose that iodide of potassium or mercury had caused so rapid a disappearance.

Syphilitic Aphasia.

What has been said of varieties of Syphilitic Hemiplegia applies mutatis mutandis to three varieties of Syphilitic Aphasia. It is to be noted, however, that so far as I know, neither syphilitic nor any other kind of tumour ever causes any considerable defect of speech. It never, I believe, causes entire loss of speech, as softening and clot often do. Of course one finds aphasia from softening due to thrombosis of a syphilitic (left) middle cerebral artery; we find it with the second variety of syphilitic hemiplegia. Epileptic Aphasia, analogous to Epileptic Hemiplegia, is not very uncommon in syphilis. The term Syphilitic Aphasia, like Traumatic Aphasia, may be useful as part of a gardener-like arrangement of cases, but it has an odd sound.

Mental Symptoms from Syphilis (Syphilitic Insanity).

That sufficiently extensive destruction of the cerebrum by any process may produce a degree of the negative mental condition, imbecility, is obvious. And, of course, syphilitic tumours may be the destroying agents directly by squeezing, or by leading to softening; or syphilis may more indirectly cause local softening by leading to arterial changes permitting thrombosis. We have already seen that syphilis leads to the negative mental condition of aphasia. However, it is not the custom to consider aphasia as a mental symptom, although really the person who has lost speech has lost a most special part of his mind. I believe, also, that syphilitic disease leads (as do other morbid processes) to another negative mental symptom as special as aphasia (imperception).

We have spoken of negative mental symptoms (hebetude, &c.), from tumours, syphilitic or other. But not only are there negative mental symptoms, there are positive mental symptoms, e. g. illusions, delusions, hallucinations, ravings, and grotesque actions. It is very important to keep distinct these two kinds of symptoms, negative and positive, for they are not only utterly different, as symptoms, which is obvious, but utterly different in their pathogeny. It is of the positive symptoms that I wish to speak most. Now, so far from the positive class of mental symptoms being the direct result of syphilis, they are never, I think,

the direct result of any morbid process whatever. It is to me incredible, that any morbid process can be the direct cause of even such caricatures of healthy mentation* as delusions, illusions, &c., are. On the contrary, the negative symptoms are always, in cases of insanity depending on disease beginning in the brain, due directly to morbid changes. Hence the statement "utterly different in their pathogeny," is not too strong a one. If this is so, I ought, were this the place and were there space at my disposal, to consider insanity much more widely than its production by syphilis demands, even in order to show how syphilis itself acts; I must, however, be content with barely stating the most general principles involved. It is in a general review of the causes of insanity, that the Principle of Dissolution, adverted to at the beginning of this paper, comes in. There is also another, the Principle of Loss of Control. Insanity is Dissolution beginning in the very highest centres. We have now to consider how the positive symptoms result.

I adopt the teaching of Monro, that there is in Insanity both a negative and a positive element; the principle stated by Anstie, that the apparent exaltation of certain faculties in disease is owing to removal of controlling influences. The same principle was independently stated by the late Thompson Dickson. (I do not follow Dr. Dickson, however, in his application of the principle to the epileptic or epileptiform paroxysm.) The Principle of Loss of Control, taken with the Principle of Dissolution, seems to me to apply to all cases of Insanity, and evidently to epileptic mania. Let us state them together, in order to show the relation of the Negative and Positive Symptoms.

Dissolution beginning in the highest centres causes directly" the Negative Symptoms of Insanity, but it only "permits" the Positive Symptoms by removing control from those centres next to the highest.

I must not pursue this subject further. I refer the reader for evidence in support of the doctrine, to chapters on "Epilepsy-Medical Press and Circular," December 9th, 1874. The following quotation from that chapter may serve to show in outline what my opinions† on the Classification of Insanity

are:

* As to peculiarities of insanity, in such cases as those called Phthisical Insanity, I must say that I see no other explanation than that these peculiarities arise, not from the particular morbid process, but from the inherited or acquired temperament of the patients who become insane.

+ I have stated that such a classification is not intended for direct utilitarian purposes; for these we must have empirical arrangements.

Cases of insanity should, I think, be classified and investigated on the basis supplied by the doctrine of Evolution of nervous centres. We shall have enormous help in the work Spencer has done in his "Psychology." We have already explained that we use the term Dissolution as the opposite of Evolution. Insanity is Dissolution beginning in the highest nervous processes. The highest processes form the anatomical substrata of consciousness. In insanity there is partial or total loss of use of the highest processes, the symptom being loss or "defect" of consciousness. Metaphorically speaking, the disease is of the controlling processes. These are negative statements. There is, stated from the positive side, reduction to a more automatic condition of mind, or, physiologically stated, a "lowering of adjustment." (See Chapter II., Part 2, Oct. 21, page 350.) The elements of the duplex condition, dissolution and automatic action, are in inverse proportion. The "shallower" the dissolution, the higher and more special (more nearly normal) is the automatic mental action permitted; the deeper the dissolution, the more general is the automatic action. The ravings, grotesque actions, visual and auditory hallucinations, &c., are due to action of centres which, except for overexcitement from loss of control, are healthy.

Epileptic Mania from Syphilis.

Mania follows those epileptic paroxysms in which there is loss of consciousness at the onset of, or very early in, the paroxysm. This is equivalent, I consider, to the statement that it follows in cases where the discharge begins in the very highest nervous centres. That syphilis produces paroxysms of this kind (commonly called genuine or true epilepsy) is certain, although it more commonly produces paroxysms in which loss of consciousness is a late event in the paroxysms.*

I do not remember, however, as coming under my own care any case of mania after a paroxysm of epilepsy (petit mal or grand mal) in a patient whose body presented conclusive evidence of syphilis. I have seen no autopsy in such a case. In all cases of epileptic mania, I should, however, apply the generalization reached when an explanation was given of epileptic hemiplegia. There is, I consider, after the discharge beginning in the highest nervous centres, a temporary exhaustion of them, just as there is of the corpus striatum in epileptic hemiplegia. The raving is, as I suggested in the last

* I would here urge again that the absolute distinction of epilepsies into cases in which consciousness is lost, and cases in which it is not lost, is not a distinction of either anatomical or physiological parentage. It is probably due to the common metaphysical habit of mind, which considers consciousness to be an entity. The distinction, even empirically, is into cases in which consciousness is lost, first of all, early or late, in the paroxysms.