laps rötheln (or imperfect measles ?) is extremely significant as to the propinquity, if not as to the identity, of the source of both the scarlatinal and the measles poisons. It is almost a forced conclusion that though the vegetations causing scarlet fever and measles are distinct one from the other (however nearly allied), the same description of soil will support them both, even if it be not the habitat of both. And an important practical corollary is, that the suppression or destruction of either one of these forms of vegetation, and the consequent prevention of the one disease, cannot be effected without the suppression or destruction of the other form of vegetation, and the consequent prevention of the other disease.

By regarding rötheln as a more or less mild measly disorder, caused by a morbilloid poison which differs from the typical (?) morbillous poison in that one or more of the ordinary ingredients of the latter poison are reduced in quantity, or modified in quality, or dropped out altogether, and also in the occasional addition of some unusual element (ustilaginous or other), the etiologist who can emancipate himself from the doctrine of contagion (as applied to the group of infective diseases under consideration) is enabled to resolve all the problems relating to incubation, desquamation, protection, exemption, susceptibility, &c. And by the light of the exhaustion of some forms and of their supplantation by other forms of "straw fungi," he may see at a glance how continuous or quickly recurring seasonal conditions may end in bringing about a second epidemic of measles or rötheln which shall vary from the previous epidemic. Thus he may understand how an epidemic of rötheln may be followed by another, among the same children, within a month or two or a year; the latter epidemic being marked by somewhat different characteristics from those of the former. These modifications, which have led so many authorities to regard the recurrent exanthem as a relapse, or as a spurious form of exanthem entirely dissociated as to origin from rötheln, may no doubt be partly due to protection from the previous attack, but are probably largely due to changes in the composition of the morbific agent.

Dr. Haig Brown's succinct account of rötheln in the Charter House School is instructive in regard to the variations in the manifestations among boys supposed to have been placed under essentially the same conditions, and to have been infected by the like specific poison—a contagium vivum, passing directly from one to the other. Mr. Davis's remarks 2 bring out very clearly the close affinity between rötheln and measles. Rötheln," he observes, "confers no immunity, neither against measles nor against scarlet fever, nor, I am persuaded, in the least degree against a recurrence of itself. During the continuance of a lingering epidemic, I have seen every member of a large family, nine months of perfect health

1 British Medical Journal, April 16, 1887.

66

2 Remarks on Rötheln by Henry Davis, British Medical Journal, October 8, 1887.

intervening, twice attacked by rötheln. . . . Some years ago, in Manchester, I saw a good deal of an epidemic of rötheln. The invasion was suggestive of measles, accompanied by sneezing, lachrymation, photophobia, fever, general malaise, a slight sore-throat and cough. About the end of the second day the eruption appeared without amelioration of the symptoms; on the contrary, the cough became frequent and harassing, &c. . . . As a very curious coincidence, if not something more, I remarked that many of those who recovered from rotheln immediately contracted a set of symptoms exactly resembling the paroxysms of whooping cough. The epidemic left upon my mind the impression that rotheln was a very serious malady, more serious than either measles or scarlet fever as they are usually seen. How different the epidemic which I have now briefly to describe!" (Cases of a mild character with slight sore-throat“epidemic herpetic sore-throat"—and presenting great variations in symptoms, desquamation, &c.).

The inquirer who can for a while set aside the view that the measles infection is specific, in the usual sense of the term, and can entertain the view that the infection is a composite poison, shall not only have the interpretation of all those changes in the symptomatology of epidemics of measles which he has been lulled into supposing to have been sufficiently explained when told that they "give the type" to the epidemic, but he shall have as well the interpretation of all the shapes and forms taken by all the congeners of measles-of which congeners rötheln, perhaps, is the nearest in blood relationship. The several phases of rötheln in England recently presented to us by Drs. Willcocks and Carpenter, by Dr. Haig Brown, and by Mr. Davis, are, even when standing by themselves, irreconcilable with the supposition of a homogeneous specific poison insusceptible of change; but when placed side by side with the divergent and strongly contrasting manifestations of the disease recorded by other observers in England and elsewhere, it is palpable that the conception that this many-sided affection is invariably caused by the one unalterable specific infective agent is little short of an absurdity. If Drs. Willcocks and Carpenter do not say as much plainly, they hint it gently; and they evidently recognise the consanguinity of rötheln and measles-a recognition, indeed, which can hardly be withheld by those who shall think the matter out for themselves: and the attempt of the nosologist to make out a title to unity in specificity for rötheln-the classification of this unstable exanthem as a distinct disease caused invariably by one immutable contagium vivum— is but "the bookish theoric."

If, therefore, the etiologist, discarding contagion from his mind for the moment, shall examine the phenomena seen in this imperfectly developed measles by the assumption that they are simply the effects of a measles poison modified as has been suggested, he shall have at all events an intelligible and a rational, if not a sound, explication of all the usual and unusual symptoms developed in this disorder:

whereas by the theory of contagion he shall find it just as impossible as all others have done to accommodate heterogeneous manifestations with homogeneous infection. A vast deal of ingenuity has been brought to bear on this question by pure contagionists; but they have beaten the air. They have not shown how a given contagium vivum can cause dissimilar effects in similar organisms.

Before leaving the subject of the alliance between measles and rötheln, I must glance at the interesting and pregnant instances of exemption given in the paper of Drs. Willcocks and Carpenter. These exemptions of a whole class were so marked and striking as to leave but little doubt that, if they had been investigated at the time with the clue afforded by the "straw mildew theory," the cause of the attacks of the medical men and nurses and of the escape of all the children might have been brought out almost to a certainty. For, in the first place, it is evident that the infected and the noninfected were not exposed equally to a common cause of infection. Secondly, it is obvious that the mode of infection was not by way of direct contagion from person to person (or the children in the wards would not have escaped). Whatever the poison was, therefore, it is to be inferred that it was localised, and that the wards did not come within the area of its efficient distribution.

The conclusion that suggests itself is, that the children's beds were either of flock or horse-hair, or of some material other than straw, and that the beds, together with the wards, were scrupulously clean; or that, if the children had paillasses, the straw in them was by some means kept dry; but that the infected adults slept on paillasses which, from seasonal conditions, or from the absence of sufficient chemical light in the bedrooms, became damp and mildewed. Of course, there is the view that the infected were exposed to an atmosphere contaminated by the vegetation growing on organic matter outside the bedroom; such as, more especially, a free surface of fœcal matter left, owing to defects at some point or points of the excreta-disposal system of the hospital, in such positions as to cause efficient air-contamination of certain rooms only. But not to delay over the question, the reader is referred to the parallel case of the exemption of the patients and the infection of the attendants in the lunatic asylums of the colony of Victoria (Chapter XVII.). The explanation submitted in regard to these sharply defined occurrences and non-occurrences of measles covers the similar phenomena observed in this more limited outbreak of rötheln.

The implication of the nurse (Case VI.) who left the hospital in good health on February 14, and in whom the rash appeared on February 28, and the after implication of other members of her family (Cases VII. to XI.), may no doubt be attributed to infection in some shape taken from the hospital to her home in Wales by Nurse M. There is no definite information in regard to local epidemics of rötheln in Wales; but as Drs. Willcocks and Carpenter state that "Case VI. was exposed to no known infection subse

quently" (to her leaving the hospital), it may be taken for granted that the limited outbreak in the house in Wales after her advent was a true extension of the disease from the hospital centre. Assuming this to be established, the question arises as to the mode of the vection of the infection. On this question it is rather difficult to gather the exact mode and the precise shape in which Drs. Willcocks and Carpenter conceive the rötheln poison to have been transported in this instance. That they take the infective agent to have been a contagium vivum is placed beyond a doubt; but whether in their opinion Nurse M. was herself the vehicle, or whether her boxes contained the contagium, stored as fomites, is left somewhat uncertain; though the following passage would seem to indicate that they held the latter view :-"She left the hospital for Wales on February 14, her boxes being packed by Case V., who developed the rash on the evening of the same day. Case VÍ. was exposed to no known infection subsequently, and the rash appeared on February 28. This gives an incubation period of about a fortnight, or rather less." The inference to be drawn from this is, that Case VI., according to the view of Drs. Willcocks and Carpenter, took the disease after leaving the hospital as a consequence of the packing of her boxes by Case V., and very shortly after her arrival in Wales and from the history of the subsequent cases, and indeed from the whole tenor of their paper, it is obvious that they contem> plated no other mode of propagation but that by way of contagion, in its recognised sense.

It is almost needless to say that, from the standpoint of the "straw mildew theory," this extension of rötheln into Wales was the result of the introduction of the spores of the causative vegetation into the nurse's home, whether through the organism or through the boxes of the nurse is immaterial, and of their growth on the matrices furnished to them in the bedding. In short, it appears to me that the singular variation in the incubation period found by Drs. Willcocks and Carpenter in the few cases they had under their observation on this occasion (and the still greater variability in this period referred to by other writers), and all the points of difference they noted in these cases, together with every recorded difference in the phenomena of outbreaks, are to be fully accounted for and reconciled only by the assumption of a varied air-contamination, caused in the manner which has been sufficiently described.

Notably the extreme variation in the stage of incubation assigned to rötheln-from six to twenty-one days-which has so much exercised etiologists, admits of easy and perfect explanation by applying to this disease what I have called the law of efficient air-contamination (and all that it involves and includes) in regard to measles. For though the law is admittedly rough and incomplete, it may nevertheless be understood by it how the degree of efficient contamination is governed by a multiplicity of conditions in such wise that it may be reached in two or three days, or may not be reached for a

fortnight or more, or may not be reached at all. This view, therefore, allows of great latitude in the incubation period without the least strain but the view of instantaneous infection by one particle of a specific contagium given off from a rötheln patient entails as a sequence that the effects of this specific contagium shall be specific, or constant and identical in all things; for it is an absurdity to suppose non-specific effects from specific causes. When, therefore, we find not only very wide differences in the symptoms of what is taken to be typical rötheln, but a markedly variable period elapsing between what is assumed to be the moment of the inception of the disease (or the first or perhaps only known exposure to contagion) and the appearance of the rash, it is a forced conclusion, either that the moment of infection has not in many instances been ascertained, or that the means by which the infection has been brought about have yet to be determined.

In fine, and in plain words, it will be evident to those who will or can reflect without bias from early training, that, as in measles so in rötheln, radical errors beset and vitiate the whole of the theory obtaining with respect to the causation and propagation of this disease. It must suffice to add, that it is almost an inferential certainty that any measures by which measles are precluded will prevent the occurrence of their congener rötheln.

2. MILIARY FEVERS.

Several forms of miliary rash, generally accompanied with profuse sweating, have appeared in epidemics. The well-known one at Rueil in 1862, that Dr. Chairou called "rougeole-suette," was very fatal; but perhaps the recent epidemic at Poitou was more typical. I take the following extracts relating to it from the Lancet (October 1, 1887):-"Under the title of 'L'Epidémie de Suette Miliare du Poitou,' M. Brouardel has contributed to the Académie de Médicine the results of the elaborate investigations made by the Commission charged with the examination of the epidemic. It appears that on March 16 of the present year there appeared during an epidemic of measles a case of 'suette miliare' in a young man aged 18, living at Sillards; this case appears to have been the first link in a long chain of cases. . . . The symptoms of the disease were usually preceded by ill-defined prodromata, such as feverishness, weakness of the legs, and general malaise, followed the next night by copious sweating. The nervous symptoms were continued feelings of suffocation, sometimes increased into paroxysms, a sense of epigastric constriction, palpitations, agitation and delirium. Cramps and contracture of muscles were also observed. . . . In the first stage cough is habitual, and epistaxis generally abundant. The second period commences with the appearance of the eruption, which presents two chief features: first, a miliary papule, transformed later into a vesicle,