CHAPTER XIX.

Instances of exemption of individuals or classes in England or elsewhere may be connected with absence of "straw fungi" contamination— The Walborough Workhouse exemption - The exemption of the school at Anerley, cited by Mr. Edwin Chadwick-The source of contamination may be missed-Cases of exemption and subsequent infection given by Thomas-Explained by original immunity and acquired susceptibility !—Why are measles endemic in one region and not in another?-Japan epidemics-Long periods of exemption incompatible with contagion-Straw mats-Contagion an impossible means of involving fifteen millions of people in a few weeks-Exemption of certain classes in England and Ireland ascribed to improved sanitation in general; but sanitation should be powerless against the hypothetical contagium vivum of measles.

AFTER detailing certain facts in my paper in the Medical Times and Gazette1 I wrote:

"It is submitted that the foregoing facts strongly support the inference reached by Dr. Salisbury. All the evidence put together, however, is but negative, and that now given of course wants confirmation. On this point I would observe that any and every epidemiologist in any part of the world may readily test my observations by inquiring into the facts connected with the incidence of measles in his own country, or in his own locality. Those facts should be on all fours with these here recorded, and it should be an easy matter to determine whether straw is an accidental or an incidental element in the occurrence of measles. In England straw is so generally used in the bedding of children that it may be hard to find instances where it has been excluded for many years from bedrooms. Yet it is not unlikely that in some dwellings, schools, reformatories, or institutions, it may have happened that straw has

1 April 28, 1877.

been replaced by other material-flock, shavings, sawdust, oakum, &c. In juvenile prisons and reformatories I suppose the inmates sleep on canvas, and are supplied with blankets only. In some naval training-schools the boys probably have hammocks, and are free from straw. In all such cases, and under all similar or parallel conditions, the children should have escaped measles at epidemical seasons. Moreover, where straw has been used for bedding in asylums, hospitals, &c., in which either idiot or sane children are received, and has been kept dry and crisp at all seasons by means corresponding to those employed in the Lunatic Asylums and Abbotsford Nunnery here, there should be the same history in regard to measles. Furthermore, I suggest that in the sunny or chimney-heated bedrooms of private houses may be found the explanation of those exceptional cases in which one or more members of a family escape during a visitation of measles. Sir W. Jenner not long since referred to an example of this kind. Other observers have recorded like examples; and, indeed, most people have known children escape when their infection has been regarded as a certainty-e.g., when a child with measles has been put to sleep with one who has not had them. These seeming aberrations from the laws of propagation are sometimes set down to the insusceptibility of the exempt; but as they may, more rationally perhaps, be ascribed to non-reception of the poison by the unaffected, it is possible that the absence of straw from bedrooms may help to account for them. Whatever doubt or obscurity may cling to these and other cases in the past, existing and future outbreaks in England will enable the inquirer to clear up. I leave it, therefore, to others to elicit the truth (for themselves) in this matter, merely observing that the question raised involves questions of far larger and higher importance than the mere suppression of measles—although this of itself would be no small boon to some nations."

These suggestions fell flat and have remained a dead letter (owing partly, perhaps, to the hastily formed conclusion of the schools that the observations of Dr. Salisbury had been upset by the experiments made in America); but they are resubmitted. For I cannot but think it most unfortunate that etiologists should have failed to detect the true nature of what was jumped at by the contagionist as absolute disproof of the "straw mildew theory," and should have allowed themselves to be so readily turned away from the most original and most pregnant, though

not as yet productive, of all the discoveries in relation to infective disease.

Little need be added to my former suggestions. Though thrown out over eleven years ago, they indicate sources of negative evidence touching the origin of measles that are unexplored, and are still open to those who may be moved to look into the question raised. There is no difficulty or complexity about it. If the straw bedding of a community governs the occurrence of measles in the community, the number of instances of exemption of individuals or classes will be in proportion to the number of instances in which straw bedding is not used, or, being used, is placed under conditions which prohibit the growth of the "straw fungi." And I reiterate that the inquirer who shall set himself, in the true spirit of inquiry, to investigate this matter for himself, will find that whilst at least 75 per cent. of the occurrences of measles can at once be seen plainly to be associated with the presence of straw bedding, all cases of exemption may be traced to an absence of straw from the bedding, or to inefficient contamination (with the "straw fungi") of the air breathed by the exempt. Let him take, for example, a case like the following:

EXEMPTION Of a Workhouse.

...

"Walborough.-. . . . Mr. Armstrong gives a curious and instructive instance of the exemption of the workhouse children, averaging eighty to one hundred in number, from infectious diseases prevalent in the town: Although the house is situated in the town, and scarlatina, measles, and whooping-cough have been frequently present among the children living in the adjoining street-the infection has never been carried over the workhouse walls. People sometimes allege, as an excuse for neglect and carelessness in carrying out sanitary precautions, that these complaints "come in the air," and that it makes no difference whether children are kept away from infected houses or not. The infective matter of these diseases is undoubtedly diffused in the atmosphere, but it is very doubtful if it ever travels even a very moderate distance in the open air, without losing its in

fective power. This instance and others well known in regard to fever and small-pox hospitals, tend to show that active infection is not wafted for unlimited miles across the country, but is confined to the immediate precincts of the sick. These poor workhouse children are not particularly isolated, and the elder ones are frequently marched through the street; but they have a school and playground to themselves, have not many outside friends to visit them, and are consequently less liable to catch infectious disease than their richer neighbours. In a sanitary point of view workhouses and prisons are becoming the most healthy places of residence, and most free from epidemic diseases.'"-Lancet, May 7, 1881, p. 758.

As an instance of class exemption this Walborough case is not perhaps beneath the attention of the etiologist and epidemiologist-though more recent cases of a similar kind could no doubt be found. Without knowing anything of this workhouse at the times of its exemption from measles, or since, I take it to be an inferential certainty that the children in its dormitories were not exposed to the effects of "straw fungi," or from some cause were not submitted to efficient air-contamination. And I apprehend that that cause would be disclosed to inquirers who could shake off such traditional views as incline them to look to the height of the workhouse walls for an explanation of the non-infection of its inmates, rather than to the conditions closely surrounding them within the walls of the workhouse. I conclude that any one who should search keenly would soon find that these workhouse children have been exempt when the other children in the town have been infected, simply because their bedding has precluded the "straw fungi" which have been growing on the bedding of the children outside the walls of the workhouse. And I unhesitatingly leave the soundness or otherwise of this conclusion to be determined by the conditions as regards the bedding which actually obtained in this case, or in any similar case, past or future, that can or may be produced.

If it can be shown that any institution in which numbers of

young children have been kept on straw bedding has been entirely free from measles during epidemics of the disease in the immediate neighbourhood, the conclusion is unsoundalways supposing, of course, that the conditions under which the straw in the bedding have been placed have not been analogous to those under which the straw in the paillasses of the Victorian lunatics have been placed; or, in other words, that the conditions were not prohibitory to efficient air-contamination with the straw fungi. The absence of straw and the non-occurrence of measles is merely negative evidence that the non-occurrence is a consequence of the absence of straw; but the presence of damp mildewed straw in positions where efficient air-contamination is here assumed to result, and the non-occurrence of measles in those exposed to the contamination for what is assumed to be the requisite time efficiently to infect, would be positive evidence that the straw fungi are not concerned in the causation of the disease. There is abundance of the former kind of evidence; but, after diligent search for many years, I have not been able to discover a single instance in which individuals or classes have remained exempt from measles during epidemics, when they have been exposed to the effects of the straw fungi equally with their infected fellows. Every phenomenon of exemption has admitted of being connected with an absence or an insufficiency of this specific poison. With this clue I have never yet failed to find that instances of special immunity, or of what have been taken to have been such, were merely examples of exemption from the absence of the straw fungi or because of an insufficient dose of them.

Another excellent illustration of the point was given in a communication addressed by Mr. Edwin Chadwick, C.B., to the Association of Public Sanitary Inspectors,1 from which I take the following:

"In the district half-time schools, with air clear from putrid, stagnant sewage in and out of the premises; with clean clothes and clean bed linen; with only one child sleeping in each bed; with equal warmth and good ventilation; and with much manual 1 Morning Post, September 20, 1887.