be contented to grapple with the obvious malady, until we know more of its antecedent pathological states. If we adopt the views of M. ROSTAN, no changes, excepting those immediately consequent upon remote causes, will be considered essential. 258. Several writers, observing the history and lesions of hydrocephalus to differ in several respects from inflammation, yet still to resemble it very closely, have viewed it as a peculiar form of inflammatory action affecting the more interior surfaces and substance of the brain. Thus, CONRADI termed it Encephalitis exudatoria infantilis; BRACHET, Hydrocéphalite, or watery inflammation of the brain; and COINDET, Cephalite interne hydrencéphalite. Other writers, particularly ABERNETHY, CURRY, CHEYNE, YEATS, THOMSON, &c., have considered it as most commonly proceeding from disease in the digestive organs, and seldom arising from primary inflammatory action in the brain or its membranes. This opinion has been carried too far; for I have often had evidence to convince me, that morbid action had been proceeding in the brain long before it was suspected, and that one of its chief effects was to disorder the liver and digestive canal; this sympathetic disorder being frequently considered as primary, and its reaction on the brain as the sympathetic production of hydrocephalus. I believe that the malady often originates in the substance of the brain; and that, conformably with what is observed in respect of lesions of this structure, the digestive viscera, frequently at one time the most remarkably deranged, are merely sympathetically affected. FORMEY and Dr. SHEARMAN have viewed the effusion as a consequence of simple excitement of the cerebral circulation, entirely independent of inflammation. The latter writer has considered it to be contingent on various diseases, and to arise from a diversity of causes; but that its occurrence is chiefly owing to the predisposition or previous state of the membranes, - the essential character of the disease consisting in that previous state or predisposition which, in connection with an excited state of the circulation, gives rise to increased exhalation or effusion. Dr. C. SMYTH has argued against inflammation, and in favour of debility, as the cause of the effusion; but whilst he has strenuously contended for the latter pathological condition as respects the tone of the extreme vessels, he has admitted the existence of accelerated circulation, and its influence in producing the disease. There is one inference, however, in which nearly all modern pathologists agree, viz., that the effusion itself does not constitute the malady, but is only its consequence, -contributing to the production of the more advanced symptoms, but in a less degree than many suppose.

259. Pathological Inferences.—(a) The first or nervous form of acute hydrocephalus is frequently consequent upon changes in the substance of the brain, in the membranes lining the ventricles, and in the vessels and circulation of the encephalon, probably arising from the state of the organic nervous influence supplied to this quarter, and to the perversion of the vital actions. (See DISEASE, § 87—92.)—(b) That these changes often coumence gradually, or almost imperceptibly, and proceed far before they disorder the functions, either of organic or of animal life, in a remarkable degree; and when such disorder becomes manifest,

it is often difficult to trace the quarter in which it has originated, owing to the intimate dependence of both classes of functions upon the organic nervous system. (c) That the changes observed on dissection in this variety have evidently been in progress a considerable time before effusion has taken place; the effusion being the consequence of these changes, assisted by the physical condition of the encephalon. (d) That nervous, as well as inflammatory and consecutive, hydroce phalus being merely contingent upon lesions of the organic nervous influence, of the circulation, and of the substance and membranes of the brain, such lesions actually constitute the disease during its early periods. -(e) That the nature of the cerebral affection, and the exact state of vascular action, in these periods, are not manifest: but if it be at all inflammatory -- which admits of dispute the vascular action possesses more of an asthenic or ataxic, than of a sthenic, character; or is attended by a perverted, rather than by a dynamic, state of vital power; and by imperfect performance of the digestive and assimilating functions.-(ƒ) That, although the first form of the disease be consecutive of changes in the cculation, or in the organic nervous influence of the brain, the resulting phenomena may be such as to be mistaken for the exciting causes; the organs of locomotion may be so enfeebled as to occasion falls, which will aggravate the primary affection, and develope a state of sub-inflammation, or of vascular reaction in the encephalon, and its usual consequences, viz. determination of blood, injection of vessels, and effusion of serous fluid; or the viscera of digestion and sanguifaetion may become so congested, or otherwise disordered, as to appear the parts primarily affected.

(g) That when this form is coincident with, or consecutive of, congestion, inflammation, or other disorders of the digestive and chylopoietic viscera, effusion into the ventricles cannot be viewed as the earliest changes that take place within the head; but that this effusion is merely conse quent upon similar changes to those which have been already alluded to (d, e); the lesions in the digestive organs, as well as the earlier alterations in the brain, being, very probably, coetaneous results of pre-existing disorder of the system, or of constitutional vice. — (h) In whatever quarter disorder commences, it is probable that, sometimes at least, the sensorial power becomes eshausted, possibly coetaneously with the supervention of the second stage, and the cerebral tissue itself more or less wasted; but it is difficult to say whether this wasting be the consequence, or the cause, of the effusion into the ventricles,— possibly the latter.—(i) That, in the early stage of the disease, as well as in its progress, the vascular excitement, or febrile disturbance, attending it, is characterised by general adynamia or perversion of vital power.-(k) That great cerebral excitement does not necessarily imply the existence of inflammatory action in the encephalon; for accelerated circulation in a weakened state of the frame, and susceptible condition of the sensorium and nervous system generally, will produce cerebral excitement, particularly towards the close of febrile or protracted diseases; but this, instead of being inflammation, is a state very different from, or sometimes even opposed to, it, as shown by the Lædentia and juvantia, and by

the post mortem appearances.—(1) In the second form, and in many of the third, particularly as occurring after the exanthemata, the symptoms, as well as the appearances after death, are more manifestly inflammatory; cases varying in grade from such as are described in the article BRAIN (§174.), until the characters of the nervous form of the disease are nearly approached; the inflammation differing in kind accordingly from sthenic inflammation, owing to the diathesis and the state of vital power.-(m) That the waterstroke or hyperacute disease, in every case in which I have observed it, has arisen independently of inflammation, although generally consequently upon determination to, or congestion in, the head. (n) That hydrocephalus, particularly its nervous form, may assume intermediate states or grades between the acute and chronic, which grades may be denominated sub-acute.—(0) That the disease may, in some instances, commence in an acute or sub-acute form, and become chronic, especially in infants whose cranial sutures have not closed. -(p) In some cases, also, the acute or subacute may supervene on the chronic state. (q) That acute dropsy in the ventricles, although most common previously to puberty, may occur at any subsequent period, especially during the decline of life, and in old age.-(r) That it is, in such circumstances, generally attended by inflammatory appearances in, or softening adjoining, the surface of the ventricles; but it sometimes is unattended by any of these lesions.-($) That in these cases it often terminates fatally in a short time, with apoplectic or comatose symptoms; constituting the Serous Apoplexy of authors, which is sometimes consequent upon other forms of dropsy in persons advanced in life; they being cut off by the effusion into the ventricles, without any other material change within the head,the coma, or apoplexy, gradually becoming more and more complete until life is extinguished.*

260. TREATMENT.-Lit. Hist. of. The opinion of Dr. WHYTT, as to the nature of acute hydrocephalus, and which was for a time very generally adopted, led to an inefficient treatment. Dr. WATSON, who adduced one of the first successful cases, trusted chiefly to blisters, purgatives, means to lower the attendant fever, and to the powers of the constitution for a cure. Drs. HAYGARTH and DOBSON were the first to prescribe mercury in the disease, particularly calomel, -a medicine which had been very largely employed about a century before, but had fallen into disuse; and which, having proved extremely efficacious in many of the maladies incidental to Europeans in the East Indies, was then finding its way, through means chiefly of Dr. LYSONS, Dr. HAMILTON, and Dr. CLARKE, into the practice of this country. Dr. DOBSON exhibited mercury with the intention of thereby increasing the function of absorption; and Dr. HAYGARTH, in order to induce salivation, with the expectation that, by procuring an aqueous evacuation from the neighbourhood, it

Since the above was sent to press the fifth volume of M. ANDRAL'S Clinique Médicale" has appeared. It contains a few cases of idiopathic and acute effusion of fluid into the ventricles, occurring in adults, both without and with slight inflammatory changes or softenings of the surfaces of these cavities, or parts adjoining. The symptoms, in these cases, were those of waterstroke, or of serous apoplexy. Two cases occurred in persons who were labouring under dropsy of other cavities.

might be the means of removing the fluid accumulated in the ventricles. Drs. A. DAWSON, SIMMONS, and WHITE placed their chief reliance on blisters and opium,- -means which, in the present state of our knowledge, amount merely to useful adjuvants. The views of Drs. QUIN, WITHERING, and RUSH caused a revolution in the treatment of acute hydrocephalus. Dr. QUIN, observing in dissection, evidences of inflammatory action in the membranes of the brain, advised bloodletting, and cold applications to the head, in the first stage, and mercury afterwards; Dr. WITHERING used digitalis, but his cases were not sufficiently demonstrative of its efficacy; and Dr. RUSH placed confidence chiefly in large bloodlettings and active purgation.

261. Dr. PERCIVAL was amongst the first who appears to have been aware of the fact, that, however nearly acute hydrocephalus may approach true inflammation, it is no more identical with it, than the adhesive form of inflammation is the same as the diffused, or as erysipelas. He directed the means which had been previously recommended, according to the circumstances of the case; and combined the use of blisters, mercurials, and opiates, with that of squills, musk, and other diuretic and nervine medicines. Consistently with these views, he was cautious in the employment of bloodletting. Dr. PATERSON prescribed calomel and opium, and a more antiphlogistic treatment than was risked by Dr. PERCIVAL; but Dr. GARNETT, although he believed in the inflammatory nature of the complaint, hardly ventured beyond local depletions; and confided more in digitalis conjoined with mercu rials, than in other internal remedies.

262. It is impossible for the experienced reader to have perused the writings on the disease, as far as I have now proceeded, without being forcibly struck with the circumstance, that great misapprehension prevailed as to the succession and ensemble of morbid phenomena, on which the name acute hydrocephalus has been imposed. This is shown by many of the cases adduced by authors in support of the inflammatory nature of the disease; these cases exhibiting the usual results of inflammation only: whilst those who observed the fluid collection unattended by very remarkable inflammatory appearances, limited their idea of this -malady to such as these only, and considered them as distinct from those evincing changes strictly referrible to inflammation, without any, or with but little effusion; which latter cases they viewed as constituting true inflammation of the brain and its membranes, and not falling within their definition of hydrocephalus, however nearly the symptoms of the one resembled (in consequence of the physical condition of the brain) those of the other. The fact is, that the larger number of writers down to the present day applied the term acute hydrocephalus to a certain succession of phenomena, without regard to the different pathological states giving rise to it, and the shades of diversity by which each may be recognised; and were either unaware of, or unheeded, the circumstance, that an inflammatory state of the brain and its membranes in young subjects may terminate without effusion, or may give rise to effusion to an extent warranting the denomination of hydrocephalus; and that, moreover, water may

be collected within the cranium, without any truly or sthenically inflammatory action of the vessels; and, nevertheless, the most experienced observers often will hardly be able to distinguish, by means of the symptoms, between these classes of cases. 263. The intentions with which the treatment of acute hydrocephalus should be conducted, are resolvable into the following:- 1st. To remove all causes of irritation or morbid action operating either directly or sympathetically on the brain. 2d. To lower vascular excitement in the head, and equalise the circulation. 3d. To guard against effusion, by fulfilling the above objects, by diverting the morbid determination of fluids from the head, and by changing the action of the extreme vessels. 4th. To restore discharges and eruptions, when these have been suppressed. 5th. To alleviate pain and sickness. - And, 6th. To support the powers of life, and to recruit them when they are sinking. It is obvious that the means which will accomplish one of these intentions, will often also fulfil one or more of the others.

264. The physician, having considered the origin, pathological states, the constitutional relations, the form, history, and stage of the disease, as well as the means which may have been already employed, should cause the patient to be placed in a well-aired chamber, and to be screened from strong light. The bed or couch should approach a slightly inclined plane, from which he ought to be slowly raised, and on which gently placed, when removal is necessary. All quick motions or changes of position, as well as excitement of the senses, and irritation of the temper, must be carefully avoided. The temperature should be rather cool than warm, and the bedclothes only sufficient to preserve the natural heat. With these preliminaries, the remedies determined upon should be promptly and faithfully administered. During both the first and second epochs of dentition, the patient's gums and teeth ought to be carefully examined, and the former freely incised, or the latter removed, as often as may be requisite.

265. A. Vascular Depletion.- In estimating the reported success of treatment in this disease, it is very necessary to keep in recollection that often no distinction has been made between it and encephalitis: indeed, many modern writers consider inflammation of the brain and its membranes, occurring in children, to be identical with acute hydrocephalus, or, in other words, that this latter is the same as the phrenitis of adults. Now this sophism, so general and injurious in medicine-this affirming as true of the genus, what is true merely of the species-has had a most baneful influence on the treatment of this disease, inasmuch as it has led practitioners greatly to over-estimate the advantages of sanguineous depletions; a large proportion of their cases of imputed acute hydrocephalus being acute and sthenic meningitis or encephalitis, in which this evacuation may be carried much further than in the former malady; and has induced them to recommend, and others to employ, the practice with too little reservation. This circumstance is especially manifest upon perusal of the histories and treatment delineated by RUSH, MAXWELL, and several others, who have carried bloodletting as far as it is admissible in sthenic inflammation

of the membranes. Having perused these authorities, after the experience derived from the treatment of very many hundred cases of cerebral diseases in children, I am convinced that the larger proportion of those which they considered hydrocephalus, was neither that malady, nor would have given rise to effusion in such quantity as to have justified the designation: the details they have furnished are decisive of the fact in the mind of the competent judge. Therefore, let not the inexperienced practitioner be led astray by the circumstance of its having been recorded by authors, that arteriotomy, large bloodlettings, &c, cured half the cases in their practice; I am convinced that the majority of such cases were simple encephalitis, or inflammation of the membranes of the base of the encephalon. Dr. MAXWELL avers that he cured sixty cases out of ninety two thirds - by bleeding them in the horizontal posture until insensibility occasionally for some hours afterwards ensued. Would the most heroic practitioner of the present day attempt such practice in an undoubted case of acute hydrocephalus ? I believe not.

266. (a) In the more inflammatory states of the disease, and especially in the first stage (§ 234.), the same means, as are fully described in the treatment of inflammations of the BRAIN and its membranes (§ 191, et seq.), should be employed; and to an extent which the pulse, the febrile excitement, and previous health and strength of the patient, will point out. These means consist of general or local bleeding, active purging, the application of cold to the head, derivatives and counter-irritants, mercury, sedatives, and diuretics, &c. In the inflammatory form, as it occurs either primarily or consecutively, these remedies may be prescribed very nearly in the manner explained in the article referred to. When the disease supervenes suddenly on any of the exanthemata, as decided depletory measures, as are advised for encephalitis thus occurring, must be pursued. (See BRAIN, § 191.) In children under three or four years of age, leeches, or cupping behind the ears, on the occiput, or on the nape of the neck, will be preferable to venæsection; but, after this age, the latter method may be practised in the first stage of the disease. I have observed no greater advantages obtained by bleeding from the jugular, than by bleeding from the arm. Many Continental physi cians consider depletion more derivative when it is practised in the feet, and numerous facts favour the inference. In the second stage, local depletions, if they have not been already employed, or carried sufficiently far, and if circumstances indicating the propriety of the practice exist, may still be resorted to; but with strict reference to the pulsation of the carotids, the pain and temperature of the head, to the warmth of the extremities, and to the state of vital power. I have often derived advantage from repeated local bleedings even in this stage, aided by the other remedies enumerated, when employed in the manner about to be described.

267. (b) In the first form, as well as in such of the third as partake chiefly of the same character, vascular depletion must be employed with greater caution, and as early as possible in the first stage. I have seen hardly any benefit from it when the second period of this variety had com