No. 319.

LONDON, SATURDAY, OCTOBER 10.

LECTURES ON SURGERY,

MEDICAL AND OPERATIVE,

DELIVERED AT

St. Bartholomew’s Hospital:

BY MR. LAWRENCE. E.

LECTURE II.

On the Nature and Seat of Diseases.IT is the object of medicine to ascertain

the nature and seat of diseases, -in order todiscover the proper modes of treating them.If we understood in each instance what or-

gans are diseased, and how they are affected,there would be very little difficulty aboutthe treatment. We should then be able to

give an alipropriate name to each disease,and to an-auge them according to their natu-ral affinities; that is, we might establish a

rational nosology. or arranged catalogue ofdiseases. Unfortunately, in a great manyinstances, we are unable to determine thenature of disease, and in not a few cases,we cannot even settle the exact seat of it.Hence you will not be surprised at findingthat our names of diseases are in many in-stances calculated to mislead, and that thosecatalogues of diseases that are called nosolo-gies, are often really (vorae than useless.The difficulties that 1 allude to, are, how-ever, not experienced so much in that partof the subject which is the immediate objectof our attention—surgical diseases; theyare more felt in atlecttons of the Ùtler71al

organs, where the means of investigation arenot so numerous, and where there is greaterdifficulty in all parta of the inquiry.

Moat persons imagine, that they under-stand very well the meaning of he<attfa and

disease ; yet it is not altogether easy to givea dfSnmo:) of thoae two states that is com-

pletelx satisfactory. Health and disease ’,lisre been said to be opposite states, and,under certain circumstances, we may admitthis representation to be correct. For ex.

ample, a person in a state of full health maybe considered to be nearly in an oppositecondition to a person in the last stage oftyphus fever. However, health and diseaseare not to be regarded simply as two statesthat can be thus contrasted ; for under eachof these terms there is included a great va-riety of conditions, differing materially fromeach other. On the one side, the state ofhealth passes, by insensible gradations, intodisease ; and on the other, the state of dis-ease is ahaded off, if we may use the ex-

pression, into health; so that when wecome to the point where the two conditionsapproach each other, we often find difficultyin determining what is health and what isdisease.The human body is an aggregate of organs,

each executing its own function, and all

concurring in the general purposes of theorganisation, which are, to preserve life, tokeep up the relations which connect theindividual with the surrounding world, andto continue the species. When the struc-ture of the organs is perfect, and when thefunctions are regularly executed, the indi-vidual is said to be well, or in a state ofhealth. The notion of health, therefore,combines these two circumstances&mdash;perfectstructure, and perfect functions, i. e. perfectin reference to the purposes just mentioned.The word 7tatu7-al, as applied to the

healthy structure, is rather equivocal, forwe must admit, that disease is a part ofnature. The French and Germans use theword normal, in order to designate what wecall the healthy structure. This term nor-mal, is about equivalent to the English ex-pression, regular. Thus the normal, regu-lar, or healthy structure, and the regularexecution of the functions, would be opposedto the diseased or the irregular structure ofthe organs, or to the imperfect or irregularexecution of the functions.

Disease haa been defined an imperfect orirregutar execution of one or more functions.This L4eiini,.ioti is very defective ; it omits acircumstance of principal importance in theconsideration of disease, namely, the stateof the organs. The definition is true, so faras it goes ; that is, wherever we see an im-perfect or irregular execution of any func-

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tion, we may safely conclude that diseaseexists. But we may have disease, and thatof a very unequivocal kind, without any ob-servable deviation from the natural state of

any function. Warts and corns are diseases;at all events, adipose antl eiicysted tumoursare so : yet those may arise, and acquireconsiderable size, without the individualbeing actually aware of their existence; andeven when they have arrived at very consi-derable magnitude, they do not disturb anyfunction ; they are, perhaps, only inconve-nient by their bulk. Cancer of the breastcommences with an induration and swellingof the mammary gland ; and these may takeplace so insensibly, as to attain a consider-able size before the female is aware thatthat disease exists, which she at last disco-vers accidentally.We may call disease a deviation from the

normal, regular, or healthy state of any solidor fluid part of the body, or of any function.These various circumstances may be exem-

plified in the case of the stomach. The sto-much may be the seat of inflammation, or ofcancer ; in both cases there is a manifestchange in the structure of the organ ; in theformer a temporary, in the latter a perma-nent change. In the case of heartburn,there is an acid secretion from the stomach ;and in the yellow ,f’ever, there is a rejectionand vomiting from the stomach of a pecu-liar dark substance, something like coffee

grounds, which is called the black vomit.Here you have the fluid secreted by thetomach completely changed. Again, innausea and sickness, and indigestion, youhave the function of the organ disturbed.You will, perhaps, be inclined to think,

that the three circumstances which are in-cluded in the definition I have now men-tioned, might be properly reduced to one.You will ask, whether the function of anorgan can be disturbed, if the structure re-main entire 1 You will inquire if thefluids can be altered, so long as the solidsremain in their natural state ? These ques-tions are very reasonable and proper. Ican ent-rtain no doubt, that if our know.ledge of disease were perfect, we should beable to trace, in every instance, the altera-tion of function to change in the state of theorgan ; but, unfortunately, our knowledge ofdisease is by no means perfect. In manyinstances we see impaired function, whenwe cannot ascertain what the condition ofthe organ is, more especially in internal dis.ease. In other cases there are alteredfunctions, or manifest symptoms of disease,but we are unable to say what organ those

symptoms should be referred to. Therefore,in our present imperfect state of knowledge,we must admit alterations in the functions,or change in the state of the fluids of thebody, as diseases, without meaning to assert

that they can take place independently ofalteration in the organs themselves.The changes which the organs may un.

dergo, differ in degree. They may be so

considerable as to be visible after death, orthere may be an alteration merely affectingthe living condition of the part, and not

leaving behind it any trace discoverableafter death. I do not believe that a functioncan be impaired while the organ remains ina perfectly regular and healthy state ; for,in fact, what are the functions of the body’!Merely the results of the exercise of the or-gans. The functions are the organs them.

selves in a state of active exertion; theorgans and the functions are causes and

effects. Perfect functions imply, natural orI healthy organs ; imperfect or irregular func-tions, suppose disordeied organs. To saythat the functions are disordered without

any change in the organs themselves, wouldbe to say that an effect has taken placewithout a cause.The organs, then, may undergo those serio

ous changes which are visible upon exami-nation after death, or they may experiencethe slightest alterations which affect merelythe living condition of the parts. The liv-

ing condition of any organ which is neces.sary for the regular execution of its func.tion, comprises not only the structure as wesee it after death, but also all the variousinternal movements. It includes a healthystate of all the fluids, whether circulating orat rest ; a regular supply of new materials,a regular removal of the old parts, the influ-ence of the nervous system, and, in manycases, the sympathetic operation of other

organs. Now nearly the whole of theselatter circumstances elude our observation ;we have no means of ascertaining them ;sometimes we see how organs are affectedby the kind of changes 1 have just nowalluded to. The function of the brain, forexample, will be suspended ; sensation andvoluntary motion will be at once put a stopto, when the action of the heart is suddenlystopped, as in syncope ; or when the func-tion of the dungs is inttrrupted, as in suffo-cation ; yet, if we examine the brain, wedo not find any change in its structure,but what happens when the heart ceases toact. No more blood is sent to the brain,and its influence ceases. When the func-tion of the lungs is stopped, the blood nolonger undergoes that change from venousto arterial, which is so essential in main-taining the action of all parts. Black bloodis sent to the brain instead of scarlet, andits functions are immediately interrupted.Thus, in both these instances, we see thatchanges in the living condition of the brainaffect its functions, though no alteration inits structure is observable after death.When we speak of a disease being func.

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tional, vre merely mean to express that it isnot accompanied by any change in the state sof the organ, observable on dissection.use functional in contra-distinction to or-ganic, which denotes visible change ofstructure.

In this country, the terms functional andorganic are often applied rather loosely. BStrictiy speaking, we should range underthe head of organic diseases all changes inthe condition of an organ which we can

ascertain by dissection. Serious changeoften takes place in inflammation, but it istransitory ; it may pass off, and leave theorgan in a state of integrity again. The

Bword organic is not used to denote that sortof change ; it is applied to permanentchanges, especially such as do not admit ofrecovery ; for example, cancer, fungus h&aelig;ma-todes, ossification, tubercles, and soon. Thesame looseness of language is observed, inthis respect, in writers of other countries.Thus Richerand does not include inflam-mation among his lesions organiqzips, butplaces it in the lesions vii ales, as if it werean affection of the vital properties of thepart.The difference between functional and

organic disease has been sometimes markedby the term disorder and disease, in our ownlanguage ; but this is not sanctioned bycommon acceptation, nor by etymology. Incommon language, disorder and disease aresynonymous; and if you come to inquireinto what is the meaning of the words, thething appears perfectly apparent. What isdisease 1 Dis-ease. An interruption of ease&mdash;a change of feeling. Then, disorder ?Dis-order. An interruption of order; thatis, an interruption of the regular functionsof the body

The examination we make after death, isnot a satisfactory criterion of the changeswhich may take place in the state of an

organ during life. Certain changes, of a

very obvious kind, take place during life,and of which we can trace nothing afterdeath. In the case of erysipelas, aud insome other diseases of the skin, there is a

very manifest determination of blood to theskin during life ; considerable diatention ofall the blood-vessels of that part ; consider-able redness of it ; but these appearancesare lost after death. The redness in oph-thalmia disappears in the same way. Wecannot therefore conclude, because we ob.&erve no change after death, that no changehas taken pace during life ; and in consi-dering whether functions can be alteredwithout disease of the organs themselves,our principal object should be to ascertain,if possible, whether there is a change in theliving condition of the part, which exami.nation after death may fail to discover.

Again ; before we can determine that no

change whatever has taken place in an or-gan, our examination after death must bevery accurate, and it should be performedunder the guidance of a full knowledge ofthe healthy, normal, or regular state of theparts ; and without the person who ex-

amines has that knowledge, it is impossibleto determine whether certain changes maynot have taken place and been overlooked.

B Thus we find, that in proportion as pa-thological investigation after death has beenconducted with greater accuracy, the num-ber of diseases, supposed to be functional,has been diminished. In the case of fevers,for example, which have been supposed tobe general diseases, more accurate patholo-gical investigation has found out, that manyorgans of the body are considerably dis-eased. To many affections of the head thesame observation applies.

The division then of diseases into func-tional and organic, in the view we nowtake, must rather be regarded as a distinc-tion in degree than in nature. In the caseof diseases called functional, the changesare such as to leave only slight, or, in manyinstances, no traces of change after deathat all ; in the diseases called organic, thealterations in the natural conditions of thepart are of a more considerable kind, andleave behind them visible appearances afterdissolution.

I can by no means agree in opinion withthose who regard functional diseases as

affections of the vital properties, without anyreference to the state of the organs. Howcan we suppose that the function of a partcan be altered, when the organ remains inthe healthy state’! ? What would you thinkif you were told by a watchmaker that awatch was perfect in all its parts, but thatits movement was affected ? But if heshould tell you,

" I have looked over thewatch very carefully ; it does not go well;,there must be something wrong, but I can-not discover where," then he would speakvery rationally, and that is the situationmedical men find themselves in, in cases offunctional disease ; they see irregularity,but do not discover what it depends on. In

’ such a case thev should conclude that theart is imperfect, or their own knowledgedeficient ; not that functions can be impair-ed while the organs are perfect.

Now this is not a point of mere specula-tive importance ; for those who believe invital, or functional disease, direct theirmeans of treatment according e their views.t 1’lieir &ucirc;bjt’ct is to remedy the imperfection; of those functions, to excite vital properties, ; which appear defective in energy, and torouse those parts to activity which seem to- , be dormant. Hence a treatment is insti-

tuted which is calculated to aggravate disease) rather than to benefit the patient. Persons

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who entertuin views of tlu. kind, seeing aparalytic affection, observe the loss oi

power only. It a patse it i3 unable to movethe limbs of one sie, they say the nervouspower is defective, and it is necessary torouse it. Thus they treat the pard) ticlimbs by stimulants of all kinds, and theyadminister general stimu:i. llore accurate

pathological research proves, in these cases,that disease exists in the head, and that itconsists, perhaps, in increased determiiia-tion of blood, in effusion of blood or serum,or in other changes that would he aggra-vated bv this stimulating treatment.

[Mr. Lawrence illustrated the same point,by referring to the tonic and stimulatingtreatment of affections of the retina, causmgimpaired vision ; to the treatment of fever,grounded on the notion of debility ; and tothat of dyspepsia, by tonics.]

It has been contended also, that thefluidscannot be altered in their properties, exceptthrough the medium of some change in thesolids. Now the. fate of the fluid part ofthe body, with reference to disease, has beenvery singular. At one period the explana-tion of disease turned entirely on changesthat were supposed to take place in thefluids ; and, at a subsequent time, it hasbeen asserted that they have nothing to doin the production of disease. At an earlyperiod, when anatomy and physiology werebut little known, the fluids were supposedto be subject, in the living body, to putrefac-tion, fermentation, concoction, acidity, alka-lescence to become thick, and thin, and soon. The means of treatment were directedwith the view of remedying such altera-tions. When anatomy and physiology cameto be investigated, and the changes that hadtaken place were observed after death, ofcourse all these notions were at once put anend to, and fr,nn that time to the present thevery term of humoral pathology, which in-cludes this sort of explanation of diseases,has become a sort of by-word of contempt.

It has been considered, that the states ofthe fluids can give no assistance in the ex-planation of diseases. Probably this is

going too far. You will consider, that allthe new materials enter the body in a fluidstate&mdash;that they are all taken up into the

system through the blood. When you con-sider the various kinds and quantities thatenter the body in this way, I think youcannot help supposing, that there must beconsiderable variations both in the quantityand in the composition of the b:ood, and thatyou cannot help admitting, that these varia-tions may have considerable influence onthe organs. Only compare, for instance, anindividual in a state of health, with a ple-thoric person, on the one side, with a scor-butic sailor, or a chlorotio female, on theother, and I think you will at once admit,

that there may be differences in the stateof blood, which may explain the conditionof disease. When we see the various statesof the urine, which we can trace to the va-riations in quantity, or kinds of food, wecannot help allowing, that the conditions ofthe fluids deserve consideration in estimat-

ing disease. We cannot help admitting,that though the doctrines which constitutedthe humoral pathoiogy were absurd, and,most of them, unfounded, this forms no

ground for excluding from our considerationaltogether, the state of the fluids. The in.

vesugation of the fluids is difficult. Animalchemistry has been cultivated, however,much of late years, and certain ingeniousfacts have been brought to light ; yet, gene.rally speaking, we cannot derive much prac.tical insight into disease, or the means ofremoving it from the state of the fluids.This, however, is no reason why we shouldnot expect, in prosecution of further inqui-ries of this kind, to derive considerable as.sistance from them.

In conclusion, Gentlemen, I may expressto you my opinion, that if diseases were

perfectly understood, we should be able, ineach instance, to refer the altered functionsto some change in an organ or organs; con.sequently, the changes in the functionswould merely constitute signs or symptomsof disease. 1 have already intimated to

you, that the state of medical knowledge isliitlierto too imperfect for such a purpose. Inmany cases, and even in some of frequentoccurrence, we are altogether unable to

distinguish the organ disturbed. Thus, forexample, in common fevers, the professionare by no means agreed as to the particularorgan, which is the primary seat of disease.

In intermittent fevers. we are quite at a

loss to assign the primary and essential seatof disease. What name should we give totetanus on this principle?

In internal diseases particularly, thechanges of functions often cannot be re-

ferred to any assignable affection of anyparticular part. We are, consequently, ob-liged to name such diseases after their ex-ternal and visible signs; being sensible, atthe same time, that the names so given areapplied rather to symptoms than to diseases.Diabetes, h&aelig;maturia, etc., are examples.Dyspn&oelig;a, asthma, and Indigestion,are analo-gous instances. If, in our present state ofknowledge, we use these terms, it must be todenote diseases ; we must bear in mind thatthey only represent symptoms, and we mustinvestigate the condition of the organs

which give rise to those symptoms, in thehope of determining the precise seat andnature of disease. All organs in the humanbody may be primarily affected; that is,they may be affected by causes acting imme-diately upon them; and all organs may also

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be affected secondarily; that is, in

conse-quence of disease previously existing insome other organ. If boiling water bepoured upon the skin, inflammation of theakin is produced. If a wound be inflicted,we have the same result; these are primaryaffections of the skin. If a person takecertain sorts of food, for instance, somekinds of sbell-fisb, or if he get his stomachdisturbed in any other way, he may have anattack of nettle-rash or urticana, the skinbeing affected secondarily, through the me-dium of the stomach. If a person have ablow on the head, or if he employ his mindintently, he may get headach, or other dis-order of the head. Again, lie may get thesame kind of symptoms if his stomach isoverloaded, or his bowels are costive. Thestomach may be disordered, and a personmay become sick, in consequence of eatingcertain food. Again, serious injuries to thehead will produce sickness, and these are

primary and secondary diseases of thestomach.

Primary disease is also called idiopathic,and secondary, sympathetic. Idiopathic dis-ease is an affection of any part produced bya cause acting immediately on that part.Secondary or sympathetic disease is excitedby the existence of disorder in some otherorgan.

I fancy there will, or, at least, there oughtto be, no difficulty in recognising that all

organs may be primarily diseased, that eachpart may be disturbed in the execution ofthose functions which naturally belong to it.Thus the lungs, stomach, intestines, urinaryorgans, &c., may be affected through causesapplied to them in the execution of theirseveral offices; yet, when persons have at-tended much to some part, they have some-times been disposed to refer all diseases toprimary disturbance of such part. Thus,one has attached very great importance todiseasen of the liver, and has fancied thisorgan to be the source of almost all disease ;another has regarded the stomach and ali-mentary canal in the same light. l’ ow I6hou)d regard all these views as partial anderroneous, and have no hesitation in believ.ing that all parts tnav be originally diseased, and, ot course, in admitting that allmay be Sfcondaritv disordered. in prohor-tion to the importance of an orryau, will bethe innuenee th,lt it may have over others.No doubt, in this poirt of view, the partsthat are concerned in the office of digestion,-the stomach, alimentary canal, ami varioussubsidiary organs, will baie great influencein exciting dist-Me in other parta, yet weruubt not loul, to them rrlotee, as the primaryseat of all disease.

In most diseases, you find sBmptomsre-fernble to both these iteads; tlat ia, ct-rtninsymptoms which arise immediarely from the

disturbed state of the organ, and others,

which are owing to the sympathetic influ-ence of that organ on other parts of thebody. When we say that one part sympa.thises with another, we merely denote thefact, that the affections are co-existing.NN hat is the meaning of the word sympathy ?It merely means suffering with. The phy-sicat is very similar to the moral sense ofthe term. When we see a person in a stateof pain, suffering, or anxiety, we feel an un-pleasant emotion ; we sympathise with theindividual. The word merely denotes thatone affection takes place in conjunction withanother. It does not explain at all how thathappens. The nerves, with the brain and

spinal chord, afford an explanation how thevarious organs are connected together intheir morbid, as well as in their naturalfunctions. The sympathetic influence ismore powerful, in proportion as the organ isof greater importance in the animal economy,as the disease in that organ is more violent,and as the individual, in whom the diseasetakes place, is more irritable.

EXPERIMENTS ON THE VIRUS OF RABID

ANIMALS.

IN No. 270 of THE LANCET, we gave anextract from a paper in Graefe and Walther’s

Journal, on the experiments which Dr.Hertwich, professor at the veterinary schoolat Berlin, had made upon rabid unimals.Having lately had an opportunity of perus-ing Dr. Hertwich’s work itself, we deemit worth while to add to the above extract

some interesting data, and especially theresults which were obtained from inocu.

lation with the saliva of rabid dogs.The two different forms of rabies, the one

of which Dr. lfufeland calls the acute or

fierce, and the other the chronic or quietrahifs, are not two distinct diseases ; forinoculation from nn animal affected with theone, was frequently observed to produce thenther. In tls’ acure rabies. the dogs wereobserved to change their manners, and tobecome either more liveiv and irritable, ormore lazy and morose ; they geneially be-come of very changeable temper, and are attimes seized with restlessness, which forcpsthem to run about : most of them know and

obey their master until a very short timebefore death. At the commencement of thedisease, the animals often show a great de-sire to lick cold things. They luse their

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appetite, especially for solid food, but fre-quently eat wood, turf, straw, or theirfaeces : this symptom is very characteristic,and the contents of the stomach in the post-mortem examinations of dogs, are of the

greatest importance to determine whetherthere has been rabies or not. No rabid dogshows a dread of water at any period of thedisease ; they drink, lick, and behold itwithout any dislike, and sometimes exhibiteven a great avidity for it, although theyoften have some difficulty in swallowing it,on account of the swelling in the throat;there is also no dread of light, nor any dis-like on looking at shining surfaces, or beingexposed to a current of air. They are verycostive, for some period at least ; and, in ge-neral, have no increased venereal desire.The most important and constant symptomis, a peculiar change in the voice, and in themanner of barking ; the sounds emitted areeither higher or deeper than usual, rough,hoarse, disagreeable, and indicative of dis-tress. The bark does not consist of repeateduninterrupted sounds, but the first bark goesinto a sort of sliort howl, so that it is neithera barking nor continued howling, but be-tween both ; during it, the mouth is liftedup, as in dogs who are made to howl bymusic. This change of the bark is veryeasily recognised after having been onceheard, and is considered by Dr. Hertwich aspathognomonic. Phlegmatic dogs, whenaffected with rabies, hardly ever show anincreased desire of biting ; but irritable,snappish dogs, are seized with a real fury,in which they attack and kill every animalwhich they can get at, and destroy and biteat every thing near them ; sometimes, even,they lacerate their own bodies. It appears,that their rage for biting is first directed

against cats, and lastly against men. Theygenerally bite without any previous barkingor growling, and the bite mostly consists ofa sudden snapping and tearing by the teethif another dog comes near them, they smelltit his mouth and genitals, and at the sametime wag with the tail before they &nap at

him ; they also often snap at the air, as if itwere to catch flies. The external appear-ance is but little changed on the first day ;on the second, the eyes become injected andsomewhat irritable by strong light; theskin at the forehead is corrugated, and theylook as if they were morose and drowsy ; ata still later period, the eyes become lifelessand turbid, as if covered with sand; thewhole face, or part of it, or the tongue,swells; they become greatly emaciated, andtheir coat is rough. As long as they areDot quite exhausted, they carry the tailturned upwards ; at the last degree of de-bility, it hangs down ; the mouth is rather

dry, and hardly ever covered with foam ;the hind legs are weak from the beginning

of the disease, and always become paralysedbefore death.

In quiet rabies, the animals are never

restless, but become dejected, very tranquil,and sad. The most important and charac-teristic symptom consists in the lower jawbanging down, as if its muscles were para-lysed ; this’depends, not, as has been assert.ed, from a spasmodic contraction of themuscles which draw down the lower jaw,but on a real paralysis of those which closeit; the lower jaw is, at least without anydifficulty, lifted up, and kept in situ by veryslight pressure. It happens, however, fre.quently, that when the animal is irritated,it recovers for a short time its faculty ofbiting, of which it appears, however, tohave no increased desire. By the abovesymptom, the dogs are prevented fromswallowing ; the saliva constantly flows outof the mouth, and the tongue is a little pro-truded. The bark is changed in the samemanner as in fierce rabies, but is very sel.dom heard, most of the dogs emitting hardlyever any sound, except when irritated. Theother symptoms, emaciation, loss of appe-tite, absence of real hydrophobia, &c., are

the same as in the other form.The duration of the disease is nearly equal

in both forms. The animals die within sixor eight days, apparently from exhaustion ; iin very few, only, sudden death, as if fromapoplexy, ensues at an earlier period.The post-mortem examination of about

200 dogs, led the author to the conclusion,that there is no constant morbid alterationfound after rabies; and he is even inclinedto assume, that wherever the post-mortemexamination of a dog exhibits no evidentcause of death, there is a great probabilityof his having been affected with rabies. Thestomach is often, but not always, inflamed,and mostly contains a reddish, yellow, or

greenish mucus, and indigestible substances,wood, stones, &c., and but seldom any food.The most interesting part of the paper

relates to the repeated experiments of ino-culating saliva, blood, and nervous substance,into fresh wounds, and administering thesesubstances internally. The following resultswill be found of the greatest importancewith respect to forensic medicine :-

1. Of 59 dogs who were inoculated, 14became affected with real rabies.

2. In those cases where the inoculationfailed, no assignable cause of the failurecould be discovered. There exists, accord.ingly, a peculiar disposition for the virus ofrabies, as for that of other contagious dis.eases. (A mastiff, four years old, went

through regular series of experiments with-out any effect being produced; while seven

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other doga, who were inoculated with him.-and in the same manner, became raiiid.Some dogs were several times inoculatedbefore any contagion took place; in others,this effect was observed after the first ex-

perimen t.)-

3. It appears, accordingly, that in casesof doubtful rabies, one or two accidental or-artificial inoculations are not sitflicient to

serve as negative proofs of the existence ojrabies.

4. No communication of the disease evertook place by the perspiration ; the conta-gious matter of rabies cannot, therefore, beof a volatile nature.

5. Its vehicle is not only saliva and themucus of the mouth, but also the blood, andthe substance of the salivary glands. Itdoes not appear to exist in the nervous

puip. -

6. The power of infecting exists at everyperiod of the confirmed disease, and even

for about tweatty-four hours after the deathof the animal.

7. The virus of rabies appears to be inac-tive if administered internally -. of 22 dogswho were made to swallow it, none tookthe disease.

8. The application of saliva to freshwounds appears to be as often followed byrabies, as the bites of rabid animals.

9. It is, consequently, beyond all doubt,that the disease is neither produced by thelesion, according to Girard’s opinion, nor bythe fear of the patient, as has been repeated-ly asserted.10. The opinion of Bader aud Capello,that in dogs who had become rabid from thebite of an animal primarily affected with thedisease, the saliva did not contain the con-tagion, and that it existed only in primaryrabies, has been proved, by several experi-ments, to be erroneous. (This perfectly agreeswith llagendie’s experiments, who, havinginoculated a dog with the saliva of a patientaffected with hydrophobia, the animal be-came rabid after a month, and bit two others,who were also infected ; from these last, nofurther contagion was observed.)

11. During the period of the inactivity ofthe virus, there is no morbid alteration ob-servab.e, either locally or in the generalhealth of the dog thus infected, nor does thelower surface of the tongue ever exhibitvesicles. There exist, accordingly, no pre-cursory symptoms as in other contagiousdiseases.

12. The disease generally breaks outwithin fifty days after the inoculation, or theinttiction of the wound ; Dr. Hertwich neverobserved it occur at a later period.

- 13. Inoculation or infection from animalsaffected with fierce rabies, very often pro.

pdnces the other modification of the disease,and vice versd ; they are, consequently,only different forms of one and the samedisease.

14. It is an erroneous opinion, that healthydogs were able to distinguish those affectedwith rabies by the smell ; this is not the

case, nor do they abhor food mixed with thesecreta or excreta of rabid dogs.

Relative to the causes of primary rabies,the author has not been led to any certain

conclusion ; the different kinds of dogs are

equally liable to it, age and sex have no in-fluence on its origin, nor the time of the

year, weather, regimen, &c. Excessive

heat or cold of the atmosphere has, accord-ing to him, no effect whatever on the de-

velopment of the disease ; this is also con-firmed by the fact of cart aud yard dogsbeing, on the average, much less affectedwith primary rabies than house-dogs.

ON RODERICK MACLEOD’S

" NECESSARY SYSTEM OF THINGS."

"Evil, be thou my good."&mdash;MILTON.

TO JAMES JOUNSTONE, ESQ., M.D.

DEAR JOHNSTONE,&mdash;The doubts which Ilast week ventured to express on the truth ofRoderick’s proposition, gain additional forcefrom the arguments by which he attemptsto support it. 11 Self-interest," lie says,"

may assume an iunnity of different shapes,but at bottom it is still the same thing; andthere may be a thousand ways of rewardingmercenary conduct, but something honour-able or profitable is always due." We didnot, my dear Doctor, want to be told, at

this time of day, of the Protean genius of" self.interest;" we have had the most

ample proofs of its versatile character. The

question is not about the existence or

quality of this attribute; but whether it can,dud how it mav, be restrained within salu-

tary bounds. Of the power and presence ofthe flood there is no doubt; we want merelyto confine it within its proper channels.Deep, constant, and forcible, as is the cur-rent of this universal motive, it may, like themightiest torrents, be made subservient tothe produc1ions of good, as the Nile, nine-