No. 1208.

OCTOBER 24, 1846,

ON THE MUTUAL RELATIONSEXISTING BETWEEN

PHYSIOLOGY AND PATHOLOGY,CHEMISTRY AND PHYSICS,

AND THE METHODS OF RESEARCH PURSUED IN THESE SCIENCES.

BY BARON LIEBIG.

EXAMPLES IN ILLUSTRATION OF THE FOREGOING GENERAL REMARKS;THEORIES OF CONTAGION; PARASITES; CHEMICAL THEORY OF THEPUTREFACTIVE AND FERMENTATIVE PROCESSES.

Deportment of Urea and Hippuric Acid in Urine.If fresh urine be kept perfectly protected from the access

of oxygen, the urea and hippuric acid contained in it undergono alteration; but upon exposure to the air, another substancepresent in the urine absorbs oxygen, and consequently suffersa change of form and properties, which is subsequently trans-mitted to the urea and hippuric acid. The urea, is resolvedinto carbonic acid and ammonia; the hippuric acid disappears,and is replaced by benzoic acid. -

Influence of the Decay of Wood upon the Oxidation of ’

, Hydrogen Gas.Decaying wood absorbs oxygen from the air, and yields to

the latter an equal volume of carbonic acid. If hydrogen beadded to the air, in contact with the decaying wood, thishydrogen acquires the property of combining with the oxygenof the air at the common temperature. Under the samecircumstances, alcoholic vapour absorbs oxygen, and is con-verted into acetic acid.

The Fibrin of Blood, and Yeast, comport themselves alike, withPeroxide of Hydrogen.

Fresh blood fibrin manifests the same deportment in theair as damp wood-viz., it passes into a state of decomposition.If, in this condition, it is brought into contact with peroxideof hydrogen, it resolves the latter instantaneously into oxygenand hydrogen, the process being attended with effervescence.But if the blood fibrin is previously heated with water to theboiling point, it loses this property of accelerating the decom-position of peroxide of hydrogen. Beer yeast, when broughtinto contact with peroxide of hydrogen, resolves the latterinstantaneously into its constituent elements: if previouslyheated to ebullition, it loses this property. (SCHLOSSBERGER.)

Deportment of Complex Organic At01ns.The complex organic atoms possess these properties in a

peculiarly high degree; in fact, the greater the number ofindividual elements and atoms that have combined into agroup of atoms, having definite properties, and the more mani-fold and varied the directions of their mutual attraction, theless, in the same proportion, must be the force that maintainsthe connexioia’ between every two or three of the ultimatemolecules of the group. They oppose to the causes tending toalter their form, condition, and properties, such as heat orchemical affinities, a far slighter resistance, and undergomodifications and decomposition far more readily than sub-stances of more simple composition.

Putrefaction.The sulphurous and nitrogenous constituents of plants and

animals belong to the most complex of organic atoms. Theinstant that these are separated from the organism, andbrought into contact with the air, decomposition commences,and continues, although the air be subsequently excluded.The colourless sections of a potato, a turnip, or an apple, acquirespeedily a brown tint in the air. In all these substances, thepresence of a certain amount of water, through which mobilityis imparted to their minutest molecules, forms an indispensablecondition to the change of form and properties, and resolutioninto new products, which the most transient contact with theair induces, and which continue incessantly until the originalbody has altogether disappeared. This process has been desig-nated by the term " putrefaction."

Affinity is not the Cause of Putrefaction.Experience has abundantly proved that many substances

alter their properties immediately when brought into contactwith such putrefying, sulphurous, and nitrogenous matters.They undergo the same decomposition with those matters,and their liberated elements combine to form new products,into the composition of which, in most cases, none of the

elements of the putrefying matter enter. These facts, takenin connexion, prove clearly that the decomposition of thesubstance thus acted upon by the putrefying matter, is notthe consequence of a manifestation of affinity, preciselybecause the idea of affinity is inseparable from that of combi-nation.

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Decomposition of Anzygdali7i, and Aspa2-agiiz, throughPutrefying substances.

In contact with the nitrogenous constituent of germinatingbarley, asparagin is resolved into succinic acid and ammonia.Amygdalin, in contact with the nitrogenous constituent ofsweet almonds, is resolved into hvdrocyanic acid, oil of bitteralmonds, and sugar; the bitter salicin into saligenin and sugar.

Conversion of Starch into Sugar.Potatoes and the flour of the cereals contain no sugar; but

the simple contact with water suffices to effect the conversionof the starch into sugar, in consequence of the change whichit induces in the sulphurous and nitrogenous constituent ofthese vegetables.

Conversion of Milk and Grape-sugar into Lactic Acid byAnimal Membrane.

Animal membrane, moistened with water, effects the trans-formation of milk and grape-sugar into lactic acid; the glutenof the cereals, animal cheese, and extract of malt, possess thesame property.

Fermentation and Fermentability.The property of organic bodies to pass, when brought into

contact with putrefying substances, into the same state ofdecomposition, or dissolution, as the latter, is termed "fer-mentability." The process of dissolution which organic bodiesthen undergo, is termed "fermentation," or, more correctly,"putrefactive fermentation;" the putrefying substance whichinduces this process of dissolution is designated by the term"ferment," or" fermentative agent."

Influence of the various stages of Putrefaction, or Dissolution,through which the ferment may successively pass, upon t7tefer-mentation of the organic body in contact with it.Now if it be true that the changes of form, condition, and

properties, which the fermenting substance has to undergo,are determined by the alterations and modifications occurringin the ferment; if the new order of arrangement. of the atomsof the fermenting body be dependent upon the mode and di-rection in which the dissevered molecules of the ferment re-arrange themselves; in short, if the fermenting body comportitself like part and parcel of the ferment-then it is obviousthat the mode of decomposition of the one must alter withthat of the other, and that the products yielded by the fer-menting substance must vary with the different stages ofdissolution through which the ferment passes.The correctness of the conclusion is demonstrated by innu-

merable facts.Milk of Almonds and Sugar.

For instance, if milk of almonds, which, in its fresh state,exercises no action upon sugar, be kept for some time, it willaltogether lose the property of acting upon amygdalin, andacquire, instead, a fermentative action upon sugar: this lattersubstance, when added to it in this state, will commence to fer-ment, and resolve itself into alcohol and carbonic acid. Milkof almonds that has been kept for a still longer period of time,effects the conversion of sugar into lactic acid. Infusion ofmalt presents very similar properties: fresh-prepared, it con-verts starch into sugar, but in about eight days it loses thisaction, and effects now the fermentation of sugar.

Casein and Sugar.In the first stage of putrefaction, animal casein effects the

conversion of milk and grape-sugar into lactic acid; and at ahigher temperature, the transmutation of grape-sugar intoalcohol and carbonic acid. In the last stage of dissolution,and the formation of free acid being prevented by addition ofan alkaline base, casein resolves the sugar atom into carbonicacid, butyric acid, and hydrogen gas.

Animal Membrane and Sugar.Animal membrane comports itself in precisely a similar

manner; at first, it effects the conversion of starch into sugar,subsequently, the transmutation of sugar into lactic acid; andfinally, the decomposition of sugar into carbonic acid andalcohol.

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Influence of Temperature upon Fermentation.The same sugar which, in beet-root juice fermenting at the

common temperature, is resolved into alcohol and carbonicacid, yields, upon elevation of the temperature, (no additionwhatever being made to the fermenting juice,) mannite, lacticacid, gum, carbonic acid, and hydrogen gas.

Production of Fousel Oil from Sugar.The same sugar, under altered conditions of fermentation,

yields butyric acid, and is, in the fermenting molasses of beet-root sugar, resolved into water, carbonic acid, and hydratedoxide of amyl, (Fousel oil.)The resolution of Sugar into Alcohol and Carbonic Acid, similar

to that of Acetic Acid into the same products, effected by theaction of Heat.

’Milk-sugar and grape-sugar contain the same elements, andin the same relative proportion as lactic acid. The productswhich grape-sugar yields upon fermentation contain exactlythe elements of the sugar atom. The decomposition of thislatter consists in a simple disseverance, or transposition of itsconstituent molecular elements, exactly as is the case withthe decomposition of acetic acid under the influence of ahigh temperature; the carbonic acid containing two-thirds ofthe oxygen, and the alcohol the whole of the hydrogen, of thesugar atom.

All highly complex Organic Atanas possess the property ofcausing Fermentation.

The fact that the property to induce putrefaction and fer-mentation belongs alike to substances of the most varied anddifferent composition, and that blood, flesh, (muscular fibre,)cheese, (casein,) membranes, cells, saliva, extract of malt, milk !;of almonds, &c., acquire this property the instant that, through Ithe chemical action of oxygen, a disturbance of the state ofequilibrium in the mutual attraction of their elements iscreated, seems to remove all doubt with respect to the truecause of all their phenomena.

Causes of change ofform, and properties, of substance.Changes of place or position of the molecules of a great

many (organic) compounds, and their resolution or transpositioninto new products, may be occasioned by chemical action, byheat, or by electricity; but they may likewise be induced bythe transmission of a state of motion, or, in other words, bycontact with substances, of which the molecules are in a stateof actual transplacement or transposition.

Propagation of Decompositionfrona one Molecule to another.When, from any external cause,-contact with oxygen, for

instance,-the state of equilibrium in the mutual attraction ofthe elements of one of these compound organic atoms is dis-turbed, a new state of equilibrium is established. The motionimparted to the first molecule is transmitted to the second,third, &c., molecule of the same element, to all the moleculesof the other elements; in short, to all other organic substancesin contact with it, whenever the power that maintains theirelements in the original form and condition is less than thatoperating upon them with an opposite tendency. Want ofpower to maintain the original state is want of power to resistexternal influences. Every substance capable of increasingthis power of resistance impedes or prevents putrefaction andfermentation; in most instances by entering into chemicalcombination with the body susceptible of either of these con-ditions. Every new accession of attractive force strengthensthe power of maintaining the original mode of moleculararrangement. To the force which strives to maintain theoriginal form and condition of the one body, is added, in thesecond body, with which this combines, a new force of attrac-tion, that must be overcome before the elements of the formercan be made to change their place or position.

Antiseptic substances.Amongst the substances which counteract putrefaction and

fermentation, we have to enumerate, in the first place, sul-phurous acid and arsenious acid, and, besides these, mineralacids, many of the metallic salts, empyreumatic substances,volatile oils, alcohol, and common salt. The action whichthese substances exercise upon putrefying bodies is of verydissimilar nature. Alcohol or common salt in certain propor-tions, for instance, stay all processes of fermentation and putre-faction simply by withdrawing from the putrefying or ferment-ing substance a certain amount of water, and thus one of theprincipal and most essential conditions of its decomposition;whilst sulphurous acid, which is capable of entering into com-

bination with organic matter in general, and consequently,likewise, with all matters susceptible of putrefaction, preventsthis and other fermenting processes by combining with theputrefying or fermenting substance.I

Deportment of Arsenious Acid with Animal Membranes.Arsenious acid does not exert the slightest influence upon

the fermentation of sugar in vegetable juices, nor upon theaction of yeast upon sugar, (Schlossberger;) nor does it arrestthe putrefaction of blood; but its action upon membranes andmembraneous tissues is unquestionable. Whilst a piece ofbladder or membrane, in contact with water, undergoes com-plete decomposition and dissolution in the course of about sixweeks, generating products of a most offensive nature, anotherpiece of bladder, or membrane, in contact with water, contain-ing an admixture of arsenious acid, remains perfectly unalteredand inodorous. The reason of their preservation is this: thatthe gelatinous tissues enter into chemical combination withthe arsenious acid, forming a compound possessed of propertiessimilar to those of the compound which skin forms with tannicacid. The knowledge of the cause of the origin and propaga-tion of putrefaction in organic atoms renders the problem ofthe nature of many forms of contagion and miasm capable ofa simple solution. This problem may be reduced to the fol-lowing terms :-

P1’Opagation of the processes of Putrefaction, or Fermentation, in the living Animal Body.

Are there facts on record, demonstrating that the state ofdecomposition or putrefaction of a substance may be trans-mitted equally to parts or constituents of the living animalorganism, and that contact with putrescent substances mayinduce in these parts or constituents of the living organism astate of decomposition, analogous to’ that of the putrescentbody? This question must be answered unhesitatingly in theaffirmative.

Facts.

It is a fact that bodies, in anatomical theatres, frequentlypass into a state of dissolution, which may be transmitted tothe blood in the living body; the slightest puncture with alancet or knife that has been used in the dissection of suchbodies is sufficient to induce a dangerous state of disease,which, in many instances, terminates fatally.Magendie observed, that " the application of putrescent

blood, cerebral substance, bile, pus, &c., to fresh wounds, occa-sions vomiting, lassitude, and finally, after a longer or shorterperiod of time, death. These observations of inlagendie re-main uncontradicted.

It is a fact likewise, that the use of many articles of food,such as meat, ham, sausages, in certain states of decomposi-tion, occasion the most dangerous diseases, and in many in-stances even death.

Definition of the term " Products of Disease."These facts demonstrate, that an animal substance in course

of decomposition may occasion disease in the body of a healthyindividual, and that its own state of dissolution may be traiis-mitted to parts or constituents of the living organism. Now,as the term " products of disease" means simply parts or con-stituents of the living body, in a state of change of form, con-dition, and properties, it is obvious, that as long as this stateof alteration is proceeding, the disease may be transmitted,through these products, to a second or third individual.

Antiseptic substances impede, or prevent, the propagation’

of Contagion and 3liasnis.If we take, moreover, into consideration, that all those sub-

’ stances or causes which tend to destrov the transmissibilitv ofcontagion and miasms impede or arrest likewise all processesof putrefaction and fermentation; that, as every day’s expe-rience shows, the process of disease in malignant suppurating

1wounds is totally modified under the influence of empyreu-matic substances, which counteract putrefaction most ener-l getically, such as wood, vinegar, (pyroligneous acid,) for in-, stance ; and finally, that in a great many contagious diseases,iand more particularly in typhus, ammonia, the almost con-7stant product of putrefactive processes, is found, either in thefree state, or in combination with other substances, in the at-- mosphere surrounding the patient, in the urine, and in theexcrement, (as phosphate of magnesia and ammonia)-it

seems impossible to entertain the slightest doubt concerning; the cause of the origin and propagation of a great many ofthe contagious diseases.

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Putoefactive Processes as causes of Coxatagious Diseases.

Finally, universal experience demonstrates that " the ori-gin of epidemic disease is frequently traceable to the putre-faction of large quantities of animal and vegetable matter, andthat miasmatic diseases are epidemic in localities where de-composition of organic matter is constantly proceeding-indamp and marshy districts, for instance, and likewise afterinundations; also in places where a large number of peopleare crowded together without suflicient ventilation or changeof air-in ships, for instance, and in jails and besieged towns."(Henle, Pathological Investigations, page 52.) And at page 57 iof the same work: "But the invasion of epidemic diseasesmay never be predicted with more positive certainty than whena marshy, flat locality has been dried up by a protracted heat,or when extensive inundations are succeeded by intense heat."

ConClusionfr01n the preceding Facts and Observations.The preceding facts and observations fully justify the con-

clusion, that in all cases where the invasion of a disease ispreceded by a putrefactive process, or where the disease maybe transmitted and propagated by solid, liquid, or gaseousproducts, eliminated from the body of the patient, and whereno more immediate cause is assignable, the substance or matteiin course and progress of decomposition is to be looked upon

;as the immediate cause of the disease in question.

Conditions of Infection.The transmission of a disease from one individual to another

requires that the body of the second individual contain matterwhich opposes to the cause of alteration of form and condi-tion operating upon it, no resistance, either in itself or throughthe vital force of the organism. If this matter forms anessential constituent of the body, the disease is transmissibleto all individuals, but if it form only an accidental constituent,only such organisms will be liable to infection as contain thismatter in the requisite quantity and condition. The diseaseitself, and its symptoms, consist in the endeavour of theorganism to destroy and remove this matter, and to establisha state of equilibrium between the inherent forces that swayand regulate its normal functions, and an extraneous forcewhich tends to alter them.

Invitation to Physiologists, and Pathologists, to examine theChemical Theory of Contagion, and llliasm.

Practical medicine will soon decide whether this view iscorrect or not; it will be seen whether there exist actual re-lations between the deportment which arsenious acid exhibitsto animal membranes severed from the organism, and theoperation of this acid in certain fevers-between the deport-ment exhibited by mercurial preparations to dead animalmatter, and the operation of such preparations in contagiousdiseases. If this so-called chemical view, deduced from acareful study of the processes of putrefaction of both singleand mixed substances, and of all the maturer causes tendingto modify, to impede or arrest, or to accelerate, such processes,and from comparison of these with analogous processes occur-ring in the organism, fails to enlarge and enrich the experi-ence of the physician, to advance and correct his insight intothe nature of diseases, and to establish the choice and appli-cation of remedial agents upon a more solid and scientificbasis than is the case at present-then it is, indeed, not worthwhile to defend and maintain it. The great obstacle to theuniversal admission of this theory seems to be its simplicity.’WInlst every physician or physiologist admits bad food, defi-cient supply of fresh air, the continued use of salted food, &c.,as causes of the most striking modifications of the vital pro.cesses, and unhesitatingly regards slight, and in many instanceshs.rdly appreciable, changes of temperature as the cause 01inflammation, fever, and death, one of the most active andpowerful causes of modifications of form and condition isdenied all share and cooperation in the organic process of life:and a theory, based upon a firmly interlinked chain oiNumerous and most evident facts, is even refused examina.tion, although nothing, save its own simplicity and facility 01comprehension, can be advanced against it. It is precisely inthis that the true characteristic of the physical method oj

investigation consists. Although every pathologist and phy-sioiogist is fully convinced that no organic process can be ex.piained without the cooperation of chemical and physicalforces, yet, up to the present time, every explanation thaiadmits the chemical and physical forces to a share of cooperation in the processes of life has been rejected by physicians.

ST. BARTHOLOMEW’S HOSPITAL.

SURGICAL REPORTS FROM THIS HOSPITAL.

BY HOLMES COOTE, ESQ.,FELLOW OF THE ROYAL COLLEGE OF SURGEONS OF ENGLAND, SURGEONTO THE NORTH LONDON OPHTHALMIC INSTITUTION, AND LATE HOUSE-SURGEON TO ST. BARTHOLOMEW’S HOSPITAL.

SARCOMA OF THE TESTICLE.

THE body of the testicle is formed of a soft, yellowish-brownmass, composed of tubuli seminiferi, bloodvessels, and nerves,enclosed in a firm, unyielding, fibrous coat-the tunica albu-ginea. When swelling occurs in the gland, from inflammatoryeffusion, from the deposit of tubercle, or from the develop-ment of a cancerous tumour, the tunica albuginea becomestightly distended, and feels to the touch as if it were thesurface of a solid, stony-hard mass. Inasmuch, then, as dis-eases cf very different character not uncommonly manifestthemselves in this situation in a somewhat similar way, theearly formation of an accurate diagnosis becomes extremelydifficult; indeed, is often impossible, from the absence of anysymptoms which would warrant our drawing a further in-fluence than that the tunica albuginea is distended by someabnormal deposit. The older surgeons included these enlarge-ments of the testicle under the one head of sarcocele" aname," says Callisen, applied to every chronic swelling ofthat organ as produces a resemblance to a hard fleshy sub-stance and Mr. Pott imagined that any testicle, thusaltered in structure, was very apt to degenerate into scirrhusor carcinoma. Although the records of surgery can furnishinstances of cancer being engrafted upon tumours of non-malignant character, such cases are comparatively rare; andmodern pathological observations teach us that, as a rule,cancerous diseases are, in their earliest deposit, as stronglypronounced as in their later and more destructive stages.True scirrhus or fibrous cancer of the testicle is an ex-

tremely rare disease. Rokitansky remarks, that "amongstthe malignant degenerations of the testicle undoubtedly allthe different forms of cancer are to be found ;"t but he leadsthe reader to infer that he himself never saw a case of truescirrhous testicle; and Mr. Curling, in a valuable work upon" Diseases of the Testis," says, " I have not witnessed any caseof this disease, which must be extremely rare:’.; 1Blr. Law-rence, in the course of his long experience, has had but twocases under his care, both of which were seen, for the firsttime, in an advanced stage, and both terminated fatally. Ofthe first case there is no record: the morbid parts were acci-dentally lost during the progress of some alterations in thehospital museum. The second case occurred during thecourse of this summer. A patient, about sixty years of age,of sallow, unhealthy aspect, was admitted into Bentley wardwith enlargement and induration of the right testicle: theinguinal absorbent glands were swelled and hardened. Uponexamining the testicle after the patient’s death, it was foundthat the natural structure was separated, and in part destroyed,by the deposit of one large central scirrhous mass, the sizeof a small bantam’s-egg, and of several softer and smallermasses, the size of peas, situated nearer the surface; the epi-didymis was hard and impervious; there was similar cancerousdegeneration in the inguinal absorbent glands. The tumourwas not examined microscopically, until after some weeks’maceration in spirit. It resembled the ordinary dense fibrouscancer, as seen in the mammary gland. I am informed byMr. Paget, that there is not one specimen of true scirrhoustesticle in the pathological collection at the Royal College ofSurgeons.The disease is described by Sir A. Cooper, in his work on

the testicle. "It is characterized," says Mr. Curling, "byits slow progress and great hardness during the whole con-tinuance of the disease, and also by its weight and irregularand tuberculated feel. It does not become soft, like en-

cephaloid cancer, and it occurs less in different parts of thebody at the same time, and is slower in proceeding to itsfatal termination."§ It will be seen, however, that up to thepresent time we are unacquainted with any symptoms bywhich the nature of the disease may be made out in its earlystages.

Medullary or soft cancer of the testicle is of not uncommonoccurrence at any period of life, from the earliest infancy to

* Systema Cilirurgiae Hodietnae.t Handbueh der Pathologisehen Anatomic, Band. iii. s. 4SS.

; Curling on 11 Diseases of the Testis."’ , Op. cit., p. 336.