which is at first slightly adherent, is detached and reproduced with great readiness. Within a period of six or seven days it may be several times renewed."* From these experiments M. Bretonneau concludes that the pellicle of cantharides is anatomically identical with that of diphtheria, and is consequently compelled to admit, in spite of the dictum of Laennec already quoted, that diseases cannot be distinguished merely by their anatomical characters. "The facts relating to the cantharidic inflammation do not in the slightest degree weaken the specificity of diphtheria; on the contrary, if we consider them in their true light and in their complete development, they prove it experimentally and demonstratively. However close may be the resemblance between the two forms of inflammation, they are distinguished by well-marked characters. The cantharidic inflammation is limited to the surfaces which have been subject to the inflaming action of the vesicant, and soon becomes extinct; which it is in the nature of the diphtheritic inflammation to extend and persist."+ This sentence involves the second part of Bretonneau's notion of diphtheria the special virulence of the diphtheritic exudation; which, however, is much more fully developed in his recent paper published in the Archives Générales de Médecine,' 1855. From this work many passages might be quoted to show that it is the opinion of the author not merely that the disease may be propagated by the application of the secretion from an affected surface to sound parts, after the manner of small-pox, but that, like syphilis, diphtheria is capable of communication from a diseased to a healthy person by no other channel. "Innumerable facts have proved that those who attend patients cannot contract diphtheria, unless the diphtheritic secretion in the liquid or pulverulent state is placed in contact with the mucous membrane, or with the skin on a point denuded of epidermis; and this application must be immediate." (Dr. Semple's Transl. p. 176.) "The Egyptian disease is not communicated by volatile invisible emanations, susceptible of being dissolved in the air and of acting at a great distance from their point of origin. It no more possesses this quality than the syphilitic disease. If the liquid which issues from an Egyptian chanere as visibly as that which proceeds from a venereal chancre, has seemed, under certain circumstances, to act like some volatile forms of virus, the mistake has arisen from its not having been studied with sufficient attention. The appearance has been taken for the reality." (Dr. Semple's Transl. p. 184.) Having thus arrived at a clear understanding of Bretonneau's theory, we may proceed to inquire how far it is rendered necessary by facts. Diphtheria is the liaison by which our author connects several affections which in the prevailing nosology of this country are separated from each other by wide intervals. Traité de la Diphthérite, p. 356. This passage is omitted in the translation. ↑ Ibid., p. 367. This term is used by Bretonneau on the supposition of the identity of diphtheria with the disease described by Aretæus as Aiyúria ëλkea. Aretæus, De Causis et Signis ac. Morb. (Ed. Kühn) p. 19. "To prove that croup is but the extreme degree of malignant angina; that malignant or gangrenous angina is not gangrenous; that there is no relation between sphacelus-between a mortification, however superficial it may be, and the alterations which this disease leaves behind it " (Dr. Semple's Transl. p. 6), this is what Bretonneau professes to have accomplished: so that according to him diphtheria includes and unites croup and angina, but excludes and separates from the latter disease gangrenous sore-throat or gangrene of the fauces. We shall endeavour to make it plain to the reader that the first two of these diseases can only be regarded as identical, if we assign the word croup a meaning which does not belong to it, and that it is impossible to describe malignant angina. in any terms which shall not include sloughing of the sub-mucous tissue as an important though not essential element. "Croup is but the extreme degree of malignant angina."-Such a doctrine accords so ill with the classical conception of croup which established itself in the mind of each of us in his first course of the practice of medicine, or on his first reading of Dr. Watson's graphic chapter on cynanche trachealis, that we are compelled to assume as the only possible explanation that our author uses the term in an entirely different sense. Dr. Francis Home, father of the late professor of medicine in Edinburgh, in a shilling pamphlet published there in the year 1765, first introduced into medical literature the word croup, which had been previously in popular use to designate a sporadic disease frequently fatal by suffocation. Although the works of previous authors from Hippocrates downwards* contain descriptions in which we cannot fail to recognise it, yet it is clear that to Home belongs the honour of for the first time defining its characters with sufficient precision to distinguish it from other germane affections. He first pointed out that the existence or formation of a false membrane in the larynx is essential to the disease, and is the source of danger; and that all its invariable symptoms are immediately dependent on this condition. Among these he drew special attention to the stridulous quality of the voice, which he compared to the crowing of a young cock, and considered to be "the true diagnostic sign of croup." He also described its insidious invasion and progress, its alternating accessions and remissions, and dwelt upon the frequent absence of all alarming symptoms, except those directly consequent on narrowing of the glottis. He regarded it as an inflammatory disease, capable of being successfully treated only by bleeding, leeches, and purgatives.t Home's description, which was derived from the careful observation of twelve cases, in ten of which post-mortem examinations were made, is the foundation on which the modern doctrine of croup was built. The conclusions of Home were not only accepted by the physicians of Great Britain, but by Rosen in Sweden, and Michaelis in Germany. They seem, however, soon to have become obscured by the prevalent • See the remarkable passage in the Prognosticum. Hippocrates (Ed. Littré), t. ii. p. 175. + Inquiry into the Nature, Cause, and Cure of the Croup (Edinb. 1765), p. 32. dogmatism of the time, or overlaid by a mass of literature consisting of partial records of observations in which the Hippocratic method of relating all the facts observed was abandoned, and those only were described which seemed to favour the views of the writer. Much of this obscurity was cleared by the appearance of the works of Cheyne in this country,* and of Vieusseux,† Jurine,‡ and Albers§ abroad, and particularly by the report drawn up by Royer-Collard. || 66 All of these were the rich fruits of the celebrated Concours instituted by the first Napoleon in consequence of the sudden death of the infant son of Louis Bonaparte and Queen Hortense. The article Croup," in the 'Dictionnaire des Sciences Médicales' (1812-22), may be considered as a résumé of all that was original in the essays presented for competition. In this essay the ideas of Home are but reproduced and enlarged; the details of the outline which the genius of the Scotch physician enabled him to sketch from so limited materials, are filled in by the author, M. Royer-Collard, from the inconceivably vast records of observation placed at his disposal as secretary of the commission. It is the leading idea of these writers that croup is an acute inflammation of the mucous membrane of the air passages, distinguished from others by the rapidity of its progress, by the existence of concrete exudation in the larynx, and by the fact that it principally attacks children under ten years of age. They regard cold and moisture as its main causes, and support this inference by all that is known as to the seasons during which the disease is most apt to occur, and the climates in which it is most prevalent; and they hold that it is its habit to select for its invasion single individuals in large populations, without communicating itself to the rest-in other words, that it is apt to be sporadic, not epidemic. Thus we see that Dr. Home's definition of croup had received the sanction of the highest authorities in France a short time before the publication of Bretonneau's first paper. Notwithstanding this, he so entirely undervalues the labours of our countryman as to express his astonishment that "A work containing only a small number of isolated and inconsistent (disparates) facts, had effaced the traces of the ancient traditions, and had exercised so great an influence for half a century on the opinion of practitioners." (Dr. Semple's Transl. p. 4.) Strange, indeed, if it were true; but we have already seen that Home's facts were not inconsistent; and that they were not isolated is evident from the general endorsement which has been accorded to them by a crowd of careful and honest observers. There is such a disease as Home described, and after him Cullen and Cheyne-a disease which is sthenic in character, sporadic as regards its origin, and is best treated by antiphlogistics. Bretonneau's laryngeal diphtheria, Essays on the Diseases of Children (Essay I.) Edinb. 1801. + Mém. sur le Croup. Geneva, 1812. Mém. sur l'Angine de Poitrine. Paris, 1815. § Commentatio de Tracheitide Infant. Leipzig, 1816. Rapport adressé à S. E. le Ministre de l'Intérieur, sur les Ouvrages envoyés au Concours sur le Croup. Paris, 1812. miscalled croup, although it closely resembles Home's disease anatomically, differs completely in its dynamical characters; it is contagious and epidemic; its exudation is an active virus, which produces in the subject of it a marked dyscrasia. "What real identity," says Dr. Cheyne,*"can there be between two diseases, the one caused by cold, the other by contagion; the one always purely inflammatory, the other generically typhoid; the one requiring a decidedly antiphlogistic treatment, the other local stimulants of the most powerful kind, tonic medicines and cordials, bark and wine, according to the procedure of our forefathers?" Having thus disposed of croup by removing it entirely beyond the limits of the discussion, we have only to deal with malignant angina, which term we understand to include all those truculent varieties of sore-throat which, in various places and at various times, have prevailed epidemically, especially among children. Is Bretonneau's diphtheria, the main features of which we have traced under his guidance, a faithful representation of this disease? The question is one of considerable extent, and could not be answered within the limits of a review. We can only endeavour to point out some of the more prominent difficulties which present themselves. Successive, and even synchronous, epidemics of sore-throat exhibit very marked differences in their characteristic symptoms and dangers, and have been frequently regarded as different diseases. Bretonneau established their identity on the firm basis of an historical comparison of the descriptions of former times with his own more exact observations; and we conceive this to be one of his most important achievements. The identity of all forms of epidemic sore-throat being admitted, it still remains, however, to be shown what, in the midst of so much variety, constitute its invariable characters. These Bretonneau has endeavoured to generalize in his conception of diphtheria; we shall see, as we proceed, that in one or two respects that generalization is defective. Maliguant angina has at all times exhibited a marked tendency to become epidemic; it has presented itself in this form in all the countries of Europe, at the end of the sixteenth century, in Spain; in the seventeenth, in Italy; and in the eighteenth, after a long interval, simultaneously in England, France, Sweden, Germany, and the United States. Its outbreaks are usually limited in extent, sometimes not spreading beyond a single building, a single village, or quarter of a large town. The experience of ancient and modern times agrees in teaching us that neither in the origin nor during the progress of an epidemic is the invasion of the disease determined by personal communication. These facts are not only not explained, but absolutely excluded, by the theory of a fixed diphtheritic virus. If malignant angina is communicable in no other way than syphilis, why does it spread in any other way ? If its material cause be concrete, and cannot under any circumstances become volatile, how can you account for its diffusion at all?—a diffusion which, we learn from our own expe Cyclop. of Pract. Med., vol. i. p. 494. rience during the last three years in this country, no less than the history of former epidemics, may be so complete as to affect every family residing within the limits of the epidemic area. And even if this objection were overcome, and it were admitted that this may be accounted for by mere inoculation, how does it happen that its prevalence is so limited, both as regards time and space, that one village or hamlet only is invaded, while others similarly situated, and in constant communication with the first, remain exempt; that it breaks out unexpectedly, remains for a few months, and disappears as if exhausted? These considerations are sufficient to show that the virus theory only needs to be confronted with facts, and we at once see that it is untenable. The agency of a concrete contagium cannot possibly explain the epidemic prevalence of any disease, and it is particularly inapplicable to malignant angina. As our space will not allow us to inquire, even in a cursory manner, how far the general characters of epidemic sore-throat-those of them which are common to all of its varieties-are fairly represented by diphtheria, we shall confine ourselves to one or two points which seem to be of special importance, namely, the constitutional state which accompanies diphtheria, and the consequent anatomical conditions of the mucous membrane. We shall find no difficulty as regards either of these in ascertaining our author's opinion. It is true that in the 'Traité de la Diphthérite,' he tells us but very little of the constitutional symptoms, the reason being that at the date of its publication he had not observed them, and for many years afterwards did not attribute to them any importance. "At the onset of diphtheria, the organic functions and those which belong to the life of relation are so little disturbed, that in general children who are already dangerously affected by malignant angina, retain their habitual appetite and continue their play. The disease only becomes mortal when the membranous layers which line the interior of the air-passages form, by their accumulation or their adherence, a mechanical obstacle to respiration... If a topical treatment modifies the diphtheritic inflammation, the return to health follows immediately on the cessation of the local disease.” * But in the recent paper in the Archives' already quoted, M. Bretonneau is compelled to modify his former views. In the epidemics which have occurred during the last few years in Paris, the disease has assumed so insidious a form, and hastened to its fatal termination in a manner so unaccountable according to the theory above expressed, that he is led to admit a new element of danger-a toxæmia, as he calls it, to which the peculiar adynamia of diphtheria is to be attributed; but he is still determined, at any cost, to keep true to the theory, that diphtheria is essentially a local disease. a local disease. Still maintaining that the constitutional phenomena of diphtheria are secondary, and therefore incapable of existing independently of the local changes, he supports his position by an assumption of facts, and endeavours to make it appear that whenever diphtheria assumes a suddenly fatal form, when • Addition Supplémentaire au Traité de la Diphth, pp. 25–27. |