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head; in the latter case, blood may be sent forcibly andrapidly to the brain, and leave it by the venous system asreadily, so that the brain only suffers from the rapid passageof the blood; in the former case, it remains in the brain, andthereby effects the pressure. If we see a patient who is onlyrecently suffering from amaurosis produced by slight con-gestion, or determination of blood to the brain, we may expectto relieve him by depletion, purgatives, a spare diet, and rest;and sometimes even they do not require any bleeding, whilstin other cases we are obliged to repeat it again and again invarious ways. Cold applications to the head, and dark rooms,are essential; but in cases of longer standing our difficulty isgreatly enhanced, and we must, in addition, apply the ordinaryremedies for amaurosis.Some years since I examined a case where the whole circle

of Willis was enlarged, and there was an aneurism at theanterior angle of it, where the trunk passes up to the middlelobes of the brain; the third pair of nerves were pressed onand much injured, as also the optic nerves. The man diedwith symptoms of apoplexy, but his vision had for a long timeentirely failed him.Many interesting cases are recorded of amaurosis from con-

cussion of the brain, some of which have been partially re-covered from; others not.

I mentioned to you that sympathetic amaurosis often occurs.I have recently had under my care a young lady, aged seven-teen or eighteen, in whom menstruation had been very irre-gular, and she had become quite amaurotic with one eye, andpartly so with the other. She has been gradually quite re-stored, but not until, by careful treatment, the uterus hadresumed its proper functions. This is not at all an uncommoncause, although this young lady’s was an extreme case. The

presence of worms in the intestines, chronic disorder of thedigestive organs, sudden chills, difficult dentition, irritation of Ithe sentient nerves from caries in the teeth, the presence ofhydrocephalus, or of scarlatina, are each of them also frequent Icauses of different degrees of amaurosis, on which I mightdilate with advantage to you, if I had time; and above all,excessive indulgence in venery, or even this, indulged in verymoderately, by weak persons, has continually proved a causeof blindness. [Some cases were now mentioned.]

I have told you how to distinguish amaurosis generallyfrom cataract, and you may distinguish it from glaucoma bythe absence of the decided green colour of the humour whichis present in the latter disease, as well as by the absence ofthe extreme hardness of the globe peculiar to glaucoma; but

you will constantly, in old cases, find them combined; andfinally, the lens becoming opaque, you have a cataraot formed.

I have now entered rather fully into a detail of the causesand characters of amaurosis, and the important question thatremains is-What treatment is to be pursued ? 1 Each casemust speak for itself, with regard to the necessity for loweringor raising the powers of the patients, or of correcting disor-dered actions. To mercury, then, are we obliged to resort forassistance, and happily we often effect more by this mostvaluable medicine than our most sanguine expectations couldhave anticipated. In some cases we find it desirable to pro-duce ptyalism as rapidly as possible; in others we are contentwith an alterative course, pursued for a length of time, inter-mitting it occasionally, and then recurring to it again; and asI mentioned in a previous lecture, we find it often very advan-tageous to combine a tonic medicine with the mercury. Ithink I scarcely need again repeat the different forms or thedoses in which we use this valuable medicine. Counter-irritation is most important in the treatment of these affec-tions, and we vary it as appears desirable. Where thestomach is foul, and when the secretions have been muchdisordered, Scarpa’s emetic plan of treatment has been consi-dered very advantageous; and in some cases a sudden partialrestoration of vision is said to have followed the exhibition ofa single emetic; and we all know well the great value ofemetics, inasmuch as they clear out the alimentary canal inboth ways. I have not seen them used much for amaurosis,excepting for that dimness of sight which follows excesses ofthe table, and for which common sense would lead us to getrid of all offending matters. Stimulants have been recom-mended occasionally, as nux vomica, camphor, strychnine,phosphorus, &c.; but they have availed nothing, as far as Ihave seen any of them used; also sedatives and antispasmodicmedicines have been occasionally given, the latter whereepilepsy has co-existed with the amaurosis; the former canonly be useful occasionally in allaying pain or irritation.Stimulating vapours, electricity, galvanism, &c., eye snuffsand different sternutatories, have been recommended also.

Sulphuric ether, or liquor ammonia, are of the first character:it has been recommended to apply these under the eyes or tothe forehead. I have not observed that they have been bene-ficial. I have occasionally thought that I had obtained muchbenefit for some patients by electricity, but not in cases oflong standing; but it is a matter of doubt with me now. Ithas been chiefly recommended for that form of amaurosiswhich followed the sudden exposure to intense lights, as bylightning &c. As to sternutatories, I have no personal ex-perience of their benefits; but Mr. Ware considered that amercurial snuff was of great advantage to those cases wherethe secretions of the conjunctiva and the Schneiderian mem-brane was deficient. He ordered one grain of Turpeth’smineral to be mixed with twenty of liquorice-powder, and afourth part of this was to be snuffed up the nose three or fourtimes a day, the patient having previously held his nose overthe steam of hot water. This may assist the mucous mem-brane, but how it is to cure amaurosis I do not understand.

ON THE ACTION OF THE KIDNEY.BY ARTHUR HILL HASSALL, M.B. LONDON.

THE quantity of urine eliminated in a given time varies veryconsiderably in health.A similar variation exists in disease also, but to an extent even

more remarkable.Sometimes the urine is in excess in both health and disease, at

others it is deficient in quantity.It is proposed in this communication to ascertain how far these

variations admit of satisfactory explanation.The extreme rapidity with which, in many cases, a large

quantity of urine is thrown off by the kidney, is one of the moststriking phenomena connected with the elimination of that fluid.The excretion or elimination of the urine is, to a very great

extent, a physical phenomenon, and is dependent upon thosegeneral laws which regulate the passage of fluids through or-ganized membranes, both vegetable and animal.One of the principal properties of membranes is that of perme-

ability, the degree varying with the character of the membrane,the nature of the fluid or fluids passing through it, and the amountof pressure to which it or they are subject.The fact or law of Dutrochet, that two fluids of different

densities pass through the membrane by which they are separated,and mingle together, the lighter fluid permeating the tissue inthe greatest proportion, and mixing with the denser, is familiarto all.A little reflection is sufficient to show that this law does not

apply to the elimination of the urine. In this case, there is reallybut one fluid, the blood ; the urine is drawn off from the blood,and is carried away nearly as fast as it collects. Moreover, theoperation of this law, if in action, would cause, not the water ofthe blood to pass into the tubules of the kidney, but the fluidwhich might be in those tubules to make its way into thebloodvessels, thus keeping the organ in a void condition.The elimination of the urine, or at all events of the watery

part of it, as well as all those of its constituents, the presence ofwhich in the blood has been satisfactorily ascertained, depends,then, primarily, upon the porosity or permeability of the mem-branes forming the coats of the bloodvessels, and of the renaltubules.The permeability of membranes is shown by the gradual dimi-

nution in the bulk of any fluid, either entirely or partially in-cluded in a membranous texture, as bladder.The passage of fluids through membranes is greatly facilitated

by pressure, their permeability being thereby much increased.A simple experiment will illustrate this.. Let the expanded portion of a curved tube be tied over withbladder, the wide part filled with water, and the upright narrowportion partially so with mercury. The external surface of thebladder will speedily become covered with drops of water; these,if the column of mercury be increased in height, will unite, andflow over, until, at length, an additional quantity of mercury beingadded, the bowl is entirely emptied of water and filled with mer-cury.Now I propose to apply this experiment to the kidney, and to

show how far it will explain the varying phenomena connectedwith the elimination of the urine.

That the contractile walls of the bloodvessels, great and small,especially those of the capillaries, exert considerable pressureupon the fluid contained within them, is undoubted; that thispressure varies, also, with the degree of contractility of the vessels,and the amount of fluid within them, is likewise very certain.

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That, also, the quantity of urine which passes through the per-meable membrane forming the tubuli uriniferi varies with thispressure, being greatest when it is greatest, and least when it isleast, follows, from what has preceded, as a matter of course; andherein we have an exact and satisfactory explanation why, undercertain circumstances, the urine is abundant, and under othersdeficient, in quantity.

It now becomes evident how admirably the kidney is suited byits structure to accomplish the office here assigned to it-viz.,that of a filter: inclosed in a dense and unyielding capsule, therepletion of the vessels of the kidney does not occasion any con-siderable distention and enlargement of the organ, but is justsufficient to put the fibrous investments on the stretch, giving Irise to increased pressure, and determining the blood towards the ’’

free surfaces of the tubules, the only outlet of relief and escape ’,for the contents of the surcharged vessels. Again, by the dispo-sition of the organ in tubules, the greatest extent of surface-animportant consideration--is obtained, with the least expanse ofspace, and with the least complexity of structure.

’

We will now enumerate the cases in which we have either an I

increase or deficiency of urine, and then proceed to ascertainhow far the principles laid down admit of application to eachcase.

There is an increase in the quantity of urine eliminated inhealth in the following cases :-

In a state of repletion of the vascular system.In impeded cutaneous transpiration.In deficient nervous energy.Under moderate exercise.

There is a decrease in the amount of urine voided in health :-In a state of the vascular system the opposite of repletion.Where there is free cutaneous action.

There is an increase in the quantity of urine passed in disease :-In hysteria.In certain structural lesions of the kidney.

There is a decrease ill disease-Where the vessels are only partially filled.In inflammatory and febrile affections.In constriction of the small intestine.In certain organic changes of the kidney.

In a state of repletion of the vascular system, as after the im-bibition of fluid in large quantities; as at breakfast, dinner, andtea, all persons must have noticed how very quickly the kidneysthrow off the excess of water. Now, in this state, the blood-vessels are distended, the contractile walls react upon their fluidcontents, and the results are, augmented pressure and increasedpenetration and escape of fluid through the membranes of thevessels of the system generally, but especially through those ofthe vessels and canaliculi of the kidney.

Where, previous to imbibition, the vascular system is in astate the opposite of repletion, where thirst exists, and the quan-tity of fluid drank is not large, consistently with the reasoningadvanced, we should not in such cases have an increased andspeedy flow of urine, the fluid imbibed being sufficient in quan-tity only to fill the vessels to their natural extent.

In impeded cutaneous perspiration, as from cold or damp ap-plied to the surface, a state of repletion or congestion of internalorgans, the kidney amongst the number, arises, and under which,as in the previous case, there is augmented pressure, and in-creased elimination of urine.Where the nervous energy is weakened, as under the influence

of the depressing passions and feelings, from fear, anxiety, disap-pointment, &c., the heart contracts with diminished strength, theblood is not propelled to the surface and extremities with theusual force, local repletion ensues, followed by the usual results,and terminating in augmented elimination.Under moderate exercise, where the vascular system is iu a

medium condition of repletion, the activity of the circulation isincreased, more blood passes through the kidney in a given time,and it is to this circumstance, rather than to pressure, that theincreased elimination is due.

In the first of those cases in which the urine is deficient inquantity in health, as where the vessels are only incompletelydistended, as happens when drink has been abstained from for along time, but little pressure is exerted upon the contained fluid,and but little urine, in consequence, passes into the tubuliuriniferi.

In the second case in which the urine is deficient in health,viz., where there is excessive cutaneous action, as in the warmweather of summer, also under the influence of the hot bath, orimmoderate exercise, a condition of vessels exists, althougharising from a different cause, similar to that described in theprevious case.

After recovery from an attack of hysteria, the condition of thenervous and vascular systems is analogous to that which obtainsunder the influence of the depressing passions and feelings, andthe explanation of the increase in the quantity of urine thrownoff by the kidney, already given, holds good in the present in-stance.The majority of the structural alterations of the kidney are

attended, not with increase, but rather with diminution of theurine ; it is difficult, however, to account for -the presence ofalbumen, unless on the supposition that the membrane of thetubules has undergone some change, which allows of the passageof that substance through it.

There are certain cases chiefly connected with disease in whichthe blood vessels are not in a state of repletion, but are only par-tially filled, as where the watery portion of the serum is carriedoff either by the bowels or the skin, as in purgation from medi-cine, diarrhoea, cholera, or excessive diaphoresis, as in hecticfever; in each of these the quantity of urine eliminated is verysmall, and this arises partly from diminished pressure, and partlyfrom increased density and inspissation of the blood.Where considerable constriction of the small intestines exists,

a mechanical difficulty is presented to the passage of the wateralong them; the absorption of fluid introduced into the stomachis consequently impeded, and the bloodvessels are thus kept in apartially filled condition, and there is therefore but little filtrationof urine through the membrane of the renal tubules.*An explanation, different from any yet given, is necessary to

account for the diminution in the quantity of urine voided ininflammatory and febrile affections. Here the vessels may be ina state of repletion, and the pressure exercised by them upon theblood considerable, and yet the urine eliminated be small in

quantity. This evidently depends upon increased density of theserum of the blood, and consequent augmented difficulty to thepassage through the membrane of the tubules.

It is here proper to remark, that the elimination of the urineis in all cases dependent, to a certain extent, upon the condition ofthe blood as to density; where the serum is very dense, theelimination is retarded, and where it is of low specific gravity, itis facilitated, and which seems to account for the fact frequentlyobserved, that in persons whose blood is habitually impoverishedthe kidneys act with facility.The same facility of action of the kidneys is observable in

individuals remarkable for the possession of a delicate organiza-tion, and in whom the coats of the bloodvessels and the membraneof the tubules may be supposed to be more than usually thin andpermeable.The organic changes of the kidney, accompanied by a diminu-

tion of the urine, are obliteration and destruction of the vesselsand tubules.

Action of Saline Diuretics.I am not aware that any satisfactory explanation of the action

of saline diuretics has yet been proposed, I therefore place beforethe profession what appears to be at least a very probable viewof their modus operandi.

Liebig, in his " Researches on the Motion of the Juices in theAnimal Body," has shown that membranes imbibe and retain aless quantity of a saline solution than they do of;water unimpreg-nated with saline matter, and less of a weak than a strong salinesolution ; and in these facts, rightly applied, we find, I believe, thecorrect explanation of the action of saline diuretics.

According to Liebig, 100 parts of animal membrane, dry ox-bladder, absorb in twenty-four hours, 268, in forty-eight hours, 310volumes of water, and only 133 of saturated solution of salt.Hence it follows, he writes, " that when bladder, saturated withwater by forty-eight hours’ contact, and well dried in bibulous paper,without pressure, to remove superfluous water, is strewed withsalt, there is formed, at all points where salt comes in contactwith the water filling the open pores, a saturated solution ofsalt, the salt contained in which diffuses itself equally in thewater of the bladder. Of the 310 volumes of water which be-come thus saturated with salt, only 133 volumes are retained inthe bladder; and, in consequence of this diminution of theabsorbent power of the bladder for the brine, 177 volumes ofliquid are expelled, and run off in drops from the surface of thebladder."The extent of membrane presented by the entire vascular

system, including especially the capillaries, is evidently verygreat.When a saline diuretic is introduced into the blood through

the stomach and small intestines, it is applied in an exceedinglyshort space of time to the whole extent of the membranes con-stituting the walls of the blood vessels; in accordance with the

* See papers by Dr, Barlow in Guy’s Hospital Reports.

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fact already noticed, the results of the application are, the dis-charge of a certain quantity of water and the contraction of thevessels. This contraction, combined with increased repletion,gives rise to augmented pressure and discharge of fluid into thetubuli uriniferi.

On Albumen in the Urine.

When it is remembered that a fluid holding albumen in solu-tion, as the serum of the blood will pass freely through bladder,it seems a remarkable circumstance that albumen is not constantlypresent in the urine in health.

I believe that we find an explanation of this circumstance inthe nature of the membrane forming the tubules of the kidney.Ordinary animal membrane, as that of the bladder, walls of the- capillaries, &c., is a fibrous tissue, whereas the membrane of thetubuli uriniferi is homogeneous, and, as far as has been ascer-tained, structureless.

While, therefore, albumen passes readily through the one formof membrane, it is very probable that the other variety, when ina state of integrity, presents a difficulty to its passage altogetherinsuperable under the usual conditions accompanying health.

If this view be correct, then there is much reason to supposethat in all cases where albumen is present in the urine, there islesion of the membrane of the tubules.The correctness of this supposition very frequently admits of

demonstration by the microscope : thus, in fatty degeneration,where the kidney is increased in dimensions, the following is the

condition of parts usually noticed : The tubes vary greatly insize, are not unfrequently more or less spirally twisted, and, inextreme cases, even torn ; their cavities are occupied either withfatty deposit, in the form of minute spherules, some of which are Iincluded in the secreting cells, but the majority are usually i,free, or else contain fibrinous coats; it is to be observed, further, i,that the larger tubes generally contain the fatty deposit in thegreatest abundance. ’

Now, accompanying the dilatation of the tubes, and which isreally the cause of the increase in the size of the entire organ, themembrane forming them must undergo some structural change,it becomes thinner, and in this state allows of the passage of thealbumen through it,

The occupation of the cavities of the tubes with the depositand fibrous coats, offers a considerable impediment to the passageof the urine and albumen, as is strikingly shown by the occasionaltwisting of the tubules.

It is, further, quite possible, that, under extreme pressure, suchas does not occur except in disease, and which possibly exists inthe congestion of the kidney occurring after scarlatina, the formof membrane constituting the walls of the renal tubules does allowof the passage of albumen through it, even without lesion.Why the form of albuminuria following upon scarlatina should

be curable, and while most other forms of that complaint, orrather, symptom of one or more complaints, should in general notbe under the control of treatment, it is not difficult to explain :the first is dependent upon local causes; the impeded action ofthe skin produces a state of temporary fulness of the vessels ofthe system, under which there is increased pressure and elimina-tion from the kidney, accompanied and modified by the localcongestion, and even inflammation, of the organ present. Thesecond form too frequently arises from general and constitutionalcauses, under which the local affection is first originated, and sub-sequently progresses.From the term albuminuria, and from the frequency with

which albumen is spoken of, in connexion with the urine, itmight, by some, be supposed, that it is the only element of theblood present in such cases : this is not, however, the case, forthe same condition of membrane which allows of the passage ofalbumen through it, permits also of the escape of the fibrin ; butwhile the first remains in solution, the latter solidifies in the renaltubules, from which they are from time to time dislodged, andare to be detected, by means of the microscope, in the sedimentof the urine.

All the elements of the blood, except the red corpuscles, aretherefore contained in the urine in ordinary cases of albu-minuria.The above brief remarks seem to illustrate the truth of the

following observations, made by Liebig, in the interesting work,the title of which has already been cited :-

" Since the chemical nature and the mechanical character ofmembranes and skins exert the greatest influence on the distribu-tion of the fluids in the animal body, the relations of each mem-brane presenting any peculiarity of structure, or of the differentglands and systems of vessels, deserve to be investigated by care-ful experiment; and it might very likely be found that in thesecretion of the milk, the bile, the urine, the sweat, &c., the mem-

branes and cell walls play a far more important part than we areinclined to ascribe to them."

General Remarks.-From the preceding observations it wouldappear, then, that the kidney is to be regarded to a great extent asa mechanical apparatus, as a filter, in fact, the action of whichdepends upon the fluid contained in it, and the pressure underwhich this is forced through.

It would be a very great error, however, to regard the elimina-tion of the urine as entirely a physical phenomenon, whollyindependent of vital influences; the nerves distributed to thebloodvessels have doubtless the power of affecting their calibre,hastening or retarding the flow of blood within them, and thus of £

giving rise to diminished or augmented pressure.How far the urine itself is to be regarded as a true secretionhas not yet been determined, seeing that the presence of verymany of its constituents has been detected in the blood, and it ispossible that they are all eliminated from that fluid.

Action of Oleaginous Purgatives.It may not be considered altogether out of place if, in this

communication, which treats of the passage of fluids throughanimal membranes, I make a few brief observations on the sub-ject of the modus operandi of oleaginous purgatives.Two fluids of different densities pass through the membrane

by which they are separated in opposite directions, and thusmingle together, the lighter fluid permeating the membrane mostquickly mixes in the greatest proportion with the heavier. Thisis the law of Dutroehet already referred to.Of this law we have a familiar illustration in the softening effect

produced by the application of oil to a salad of lettuce; thedivided leaves, at first crisp and juicy, soon become soft andflaccid, the water included in the cells of the vegetable tissueescapes, while a portion of the oil is absorbed in less proportionto supply its place.Now the action which comes into operation when oil is poured

into the intestines is of a precisely similar nature; the fluid of thebloodvessels of the villi and follicles being less dense than theoil, escapes into the cavity of the intestines, while a part of theoil is taken up; the increased quantity of fluid in the intestinesexcites peristaltic action, and the passage of the foecal matter isfacilitated.

Other examples of the increased permeability of membranes tofluids under augmented pressure might be cited, and the greatelimination of the watery part of mucus in catarrh is probablyanother manifestation of the same law.

Notting-hill, August, 1850.

PRACTICAL ILLUSTRATIONS OF THE REME-DIAL EFFICACY OF A VERY LOW OR ANÆS-THETIC TEMPERATURE.—I. IN CANCER.

BY JAMES ARNOTT, M.D.PHYSICIAN TO THE BRIGHTON DISPENSARY.

HAVING already given an account of the antiphlogistic andanodyne properties of a very low or benumbing temperature inthe treatment of erysipelas, headache, and other cutaneous andneuralgic affections, as well as of its utility as an ansesthetic, inmany surgical operations, in lieu of the inhalation of ether orchloroform,* I proceed, on the present occasion, to lay before theprofession some details respecting other important applications ofthe same valuable therapeutical agent. I shall show, in the firstplace, by a report of a case of cancer treated by an anaesthetictemperature or congelation, that it furnishes us with a perfectmeans of relieving the pain of that dreadful disease, without pro-ducing the stupefaction and disturbance of the system that attendsthe use of narcotics; and that, instead of precipitating the unfor-tunate patient’s fate, like these, congelation, by arresting the ac-companying inflammation, and perhaps destroying the vitality ofthe cancer cell," is not only calculated to prolong life for a greatperiod, but may, not improbably, in the early stage of the disease,exert a curative action.

If it be objected that the case to be reported is insufficientevidence of this property of congelation, I would reply, that theunequivocal, immediate, and long-enduring relief from sufferingwhich it shows to have been effected by each of numerous appli-cations, during a period of eight months, together with therestoration of the patient’s general health, in consequence of thearrest of the local disease, leave no doubt on this point, andrender a single case hardly less satisfactory than a multitude

* See THE LANCET. September 9, 1848, and a Treatise on the diseaseaabove specified, published last year.