Regarding the epidemics of small-pox that raged in the Grand Duchy of Hesse in the course of the nineteenth century, Reissner and Neidhart^[289] have published an excellent book. Vaccination, at least once, was made compulsory in Hesse in the year 1807. According to the above-mentioned book, small-pox was prevalent in Hesse all the time; the average number of deaths per annum in the years 1863–8 was O·47 per 10,000 inhabitants. After the year 1868 the statistics read as follows:

The increased prevalence of the disease began in September; the following table indicates the number of deaths in the several months:

While small-pox made its appearance here and there in the first half of the year 1870, it did not acquire epidemic dimensions until after the outbreak of the war. In many places, to be sure, it was impossible to prove that the disease was directly connected with the war. Reissner and Neidhart mention numerous cases in which the disease was communicated by field-soldiers who were sent from France to Hessian reserve-lazarets (Pfungstadt, Lampertheim, Crumstadt, and others), by furloughed field-soldiers (Lauterbach, Lorsch, Eschollbrücken, and others), by fugitives from Paris at the beginning of the war (Giessen, Gross-Eichen), by French prisoners who had contracted the disease in camp or during transport, by teamsters returning home from France (Worms, Grossgerau), by military effects—such as carpets, clothing, tent-canvas (three places in the district of Grossgerau), and especially by people who had visited the prisons where the French soldiers were confined (Mayence, Darmstadt, &c.).

Not a single district in Hesse was spared during the epidemic of the years 1870–2. The district of Mayence suffered worst of all; then came Giessen, Offenbach, and Darmstadt, all districts in which moderately large cities were located. The following table indicates the number of deaths per 10,000 inhabitants in the various cities and districts:

In the city of Mayence about thirty cases of small-pox were reported in the year 1870 before the war broke out. ‘Shortly after the beginning of the war,’ say Reissner and Neidhart, ‘numerous prisoners were interned in Mayence, and among them cases of small-pox had not infrequently been observed beforehand. Notwithstanding the admonitions of the military physician, a barrack inside the city was set aside as a lazaret for them. At first in the near-by streets, but later on throughout the entire city, an epidemic now began to rage such as Mayence had never before experienced in the memory of man. It lasted throughout the entire year of 1871 and did not come to an end until the middle of the following year.’ The epidemic reached its climax in Mayence in January 1871, abated a little until March, started up again in April, and then slowly decreased in fury until it finally disappeared altogether. In the garrison at Mayence 190 men contracted the disease in the years 1870–2 and nine succumbed to it; of the prisoners of war 934 contracted the disease and seventeen per cent of them died. The pestilence was disseminated in all directions from Mayence, partly by people from the surrounding country who visited the city, and partly by other means. Thus, for example, the disease broke out with unusual severity in Bretzenheim, a village situated a mile or so away from the barracks where the prisoners were confined; the inhabitants of the village in many instances used the contents of the ditches in which the defecations of the prisoners were thrown to fertilize their fields, and they also bought straw and other waste products in the city.

In the city of Giessen no cases of small-pox occurred in the year 1870 prior to the outbreak of the war. The first cases observed there were in September, but the epidemic, which reached its climax in December, did not become very widespread. In Darmstadt 50 cases of small-pox were reported in the year 1870 prior to the outbreak of the war, and after the war began some 50–60 cases were observed before the end of the year. The epidemic, which became only moderately widespread, lasted throughout the entire year of 1871 and did not disappear until the middle of the year 1872.

In connexion with the Franco-German War an epidemic of small-pox raged throughout Germany, the extent and virulence of which exceeded that of any other epidemic that occurred in the entire course of the nineteenth century. Unfortunately, in the case of a number of small States, we have no statistics relating to the number of deaths caused by the disease. The figures which I was able to obtain I have compiled in the following table. In the case of Alsace and Lorraine, as well as of Oldenburg, the two Mecklenburgs, and the other small North German States, absolutely no figures are available; judging by their population and by the prevalence of small-pox in the States surrounding them, we may safely estimate the number of deaths caused by small-pox in them in the years 1871–2 at some 4,000.

The above compilation leaves no doubt that the disease was borne into Germany from France. The contagion was conveyed into Germany by prisoners and field-soldiers, some of whom were infected beforehand and were sick when they got there, others of whom were still apparently healthy, and still others of whom had reached the convalescent stage of the disease, and less frequently by civil persons (teamsters and fugitives); but the prisoners were by far the most active influence in spreading the disease. The dissemination usually took place in the following manner; in the dépôts where the prisoners were confined, small-pox epidemics of varying severity broke out; from all sides the people streamed in to see the prisoners, and when they went away they conveyed the infection wherever they went, at first, of course, around in the immediate vicinity. This is most evident in the eastern provinces, where these dépôts soon came to be dangerous seats of small-pox infection; the near-by districts were very severely attacked as early as the year 1871, whereas the more remote districts did not begin to suffer severely until the year 1872.

The development of a small trade between the prisoners and civil inhabitants in articles belonging to dead soldiers, or in personal effects, also helped to spread the disease; moreover, certain unscrupulous sick-attendants, when they were instructed to destroy such articles, frequently disobeyed the order and secretly sold them, thereby giving an additional impetus to the dissemination of the disease.

The fact that a large part of the population was not vaccinated, and that the necessity of revaccination was not properly recognized (only soldiers were revaccinated), also helped to increase the severity of the pestilence. In all the South German States compulsory vaccination had existed for decades, but its strict enforcement was everywhere hindered by the activity of the anti-vaccinationists; Prussia and Saxony did not introduce compulsory vaccination until the year 1874. Revaccination among the civil inhabitants was rarely practised in either North or South Germany. These differences in the vaccination laws account for the fact that small-pox raged more severely in North Germany than in South Germany; this is also distinctly shown by the tables reproduced in the course of this chapter. The fact that the civil inhabitants in general were more thoroughly vaccinated also explains why the percentage of children that succumbed to small-pox was so much smaller in South Germany than in North Germany.

The number of deaths caused by small-pox in the epidemic of the years 1870–2 was greatly increased by the extremely virulent character of the disease. Of course one cannot estimate the number of deaths caused by small-pox among the civil inhabitants from the number of reported cases of the disease, since the reports sent in were always very incomplete. We know that the mortality of small-pox depends very much upon vaccination; vaccinated persons succumb far less frequently to the disease than unvaccinated persons. This fact explains why among the German field-soldiers, who were constantly subjected to hardships and privations of all kinds, only 5·75 per cent of the patients died, whereas of the French prisoners some 13·85 per cent died. The mortality among the civil inhabitants of Germany was also very high; this was chiefly due to the fact that severe forms of the disease, particularly hemorrhagic small-pox, were of frequent occurrence. As authority for this we can only refer to these reports of the hospitals; but since small children, amongst whom the mortality of small-pox is very high, are less represented in them, and, on the other hand, since mild cases among adults can more readily be withdrawn from hospital treatment, one cannot accept without qualification the experience of the hospitals. According to Wunderlich, of 681 patients treated in the Leipzig hospital between the year 1852 and July 1870, only 29 (4·2 per cent) died, whereas in the years 1870–1, of 1,727 patients treated, 253 (14·7 per cent) died. In Breslau, whereas in former epidemics an average of seven per cent of the patients died, in the epidemic of the years 1871–2 no less than 13·4 per cent died. Guttstadt also states that the mortality in the Berlin hospitals was fifteen per cent, whereas the number of deaths caused by the disease in former years was much smaller. We have seen above that 21·7 per cent of the patients taken to the Hôtel-Dieu in Lyons died. It is unnecessary to adduce further statistics; all contemporary observers agreed that the epidemic involved an extremely severe and virulent form of the disease, and that this same virulence characterized the disease wherever it made its appearance.

5. The Epidemics of Small-pox that raged in the European, and in a few of the non-European States in connexion with the Franco-German War of 1870–1

(a) Switzerland

Switzerland was exposed to great danger in consequence of the passage of General Bourbaki’s army, which consisted partly of very young soldiers who had suffered great hardships, including cold and hunger, and which contained large numbers of men who were suffering from small-pox. The little country was called upon to take in some 85,000 men; when the latter were examined on the frontier a large number of them were found to be infected with small-pox and were held at Verrière in France. But this did not prevent the disease from being conveyed across the border. Of the French prisoners confined there, 137, all told, succumbed to small-pox.

Unfortunately no mortality statistics giving the cause of death were compiled in Switzerland until the year 1876, so that we have no figures indicating the prevalence of small-pox. The western cantons were most exposed to the infection. In Berne, which at that time had a population of 506,511, no less than 2,637 persons, excluding the French prisoners interned there, contracted the disease between October 1870 and September 1872; in the year 1871 there were 9·6 deaths per 10,000 inhabitants.^[293] In the city of Basel, which was attacked as early as November 1870, the epidemic reached its climax in February; the number of deaths there was as follows:^[294]

The Canton of Basel (Land) was attacked somewhat less severely; in the year 1871 only 59 persons (10·9 per 10,000 inhabitants) succumbed there to small-pox. In the Canton of Solothurn, which was infected from Olten, a railway junction, 13·9 persons per 10,000 inhabitants died in the year 1871. In the Canton of Waadt small-pox broke out, according to Vogt, in the district of Vivis in November 1870, and 200 persons contracted the disease in the course of that month. In the two small-pox hospitals at Lausanne, 351 patients were treated between November 20, 1870, and the end of 1871, and 62 of them died.

The small-pox epidemic spread very rapidly from the West throughout all the rest of Switzerland, partly in consequence of the distribution of the French prisoners among the other cantons, and partly in consequence of inland intercourse. Of the French prisoners interned in the Canton of Zurich 180, according to A. Brunner,^[295] contracted the disease and 31 died of it. The patients were sheltered in the small-pox camp at Winterthur, whence the infection spread to many places. In February 1871 there was a rapid increase in the number of cases; the epidemic reached its climax in March and April, and then steadily abated until June. The statistics for the Canton of Zurich, which had a population of 285,915, were as follows:

In the Canton of Thurgau, according to Vogt, there were 9·2 deaths per 10,000 inhabitants in the year 1871, in the Canton of Schaffhausen 4·0, and in the Canton of St. Gall 3·3. During the small-pox epidemic that raged in the Canton of Schwyz in the year 1871 the communities of Gersau and Küssnacht were severely attacked; throughout the entire canton 56 persons (11·7 per 10,000 inhabitants) succumbed to the disease. The Cantons of Glarus, Unterwalden, Zug, and Graubünden were also rather severely attacked. In the Canton of Tessin, whither the disease, which first appeared in Locarno, had been conveyed by travellers from Paris, and where 62 cases of it and 6 deaths had been reported up to June, a new epidemic broke out in Personico, resulting in 15 deaths; in the year 1871 there were 11 deaths reported throughout the entire canton. In the Canton of Willis small-pox broke out only sporadically.

(b) Belgium

In numerous places throughout Belgium small-pox had appeared in the first part of the year 1870 in the form of widespread epidemics, a fact which we can readily explain when we consider the country’s proximity to France, which was everywhere infected with the disease. Thus, according to Larondelle, a severe epidemic of small-pox broke out in February 1870, in the city of Verviers, which at that time had some 33,000 inhabitants, and lasted until January 1871; in the year 1870 no less than 428 deaths were reported there, and 185 of them occurred in the month of December alone. When the war began French fugitives kept bringing the disease into the country, especially after the battle of Sedan, when more than 10,000 French soldiers were interned on Belgian soil, some in Beverloo and others in the citadel of Antwerp. From these places the epidemic spread throughout all Belgium. In Brussels, for example, no cases of small-pox were reported in July 1870, in August there were two cases, in September two, in October twenty-two, in November sixty-nine, and in December 101. In all Belgium the number of deaths caused by small-pox was:^[296]

(c) Netherlands

In the Netherlands an epidemic of small-pox had raged in the year 1866; in the following year it had rapidly abated, and in the year 1869 had caused only fifty deaths in the three provinces of North Holland, Utrecht, and Limburg combined. In the year 1870 the number of deaths increased considerably, and in the following year reached an appalling height.^[297] The following table indicates the annual mortality of the disease:

Thus both Belgium and the Netherlands had a very high small-pox mortality in the year 1871; as elsewhere, the cause is traceable to repeated transplantations of the disease, and to the fact that vaccination was insufficiently practised.

In the years 1872–4 Austria suffered severely from small-pox; the total number of deaths per annum caused by the disease is indicated by the following table:^[298]

Although small-pox was usually conveyed into Austria from the East and South (Italy), nevertheless the connexion between the epidemic in Austria of the years 1872–4, and the great German epidemic is too obvious to be overlooked. This is clearly shown by the successive appearances of the disease in the various crown-lands, the number of deaths per 10,000 inhabitants in which is indicated by the following table:

These relative percentages were based upon a mean population computed from two censuses, one taken in 1869 and the other in 1880.

We see how the epidemic gradually penetrated into Austria, and how Triest at a very early date became a second focus of the dissemination. In the year 1870 the small-pox mortality was generally low in Austria. The small epidemic in Bukowina in the year 1871 had no causal connexion with the Franco-German War; it was an epidemic such as had often broken out in former years in the countries of eastern Austria, and such as still break out occasionally nowadays. On the other hand, a considerable increase in the number of deaths caused by small-pox is observed in the year 1871 in Lower Austria and Salzburg, and to a certain extent in East Austria, Moravia, Silesia, and Bohemia; in Lower Austria, Salzburg, and Silesia the epidemic reached its climax in the year 1872, whereas in Upper Austria, Bohemia, and Moravia this climax did not come until the year 1873. The same is true of Vorarlberg, while the crown-lands of Styria, Carinthia, Carniola, and Tyrol were most severely attacked by the disease in 1874. In Triest and Istria the climax of the epidemic was reached in 1872, in Görz and Gradiska in 1873. In Galicia, which had always had a high small-pox mortality, the epidemic did not begin until the year 1872; it reached its climax in the following year. In Bukowina the climax did not come until the year 1874.

‘To follow the progress of the disease according to political districts,’ says Daimer, ‘is instructive for the reason that, as was clearly shown at that time, it always spread slowly—a fact which was also repeatedly observed in the case of other epidemics; thus, there was always time enough to adopt appropriate measures aiming to check its progress.’ There is a very marked difference between the epidemic of small-pox in East Austria and the one in Germany; the latter attacked all Germany within a short time, since the war had developed there a very extensive intercourse. And even in Germany it was observed that the disease was a long time in reaching those regions that were less affected by this intercourse.

Vienna was attacked with great severity by small-pox; so also was Prague, though to a lesser extent. The following table indicates the number of deaths caused by the disease per 10,000 inhabitants:

But in these cities the epidemic did not come to an end; epidemic outbreaks of small-pox continued to occur in Vienna until 1885, in Prague until 1893, and in a number of years (for example, 1877, 1880, 1883, 1884, and 1888) the disease underwent some very important exacerbations.

(e) Italy

Small-pox is supposed to have been conveyed into Italy by the volunteers who had fought under Garibaldi; they became infected with the disease in the Department of Côte d’Or, where it had raged extensively, and then brought it back with them when they returned home. In Milan 200–300 cases per annum were usually reported prior to the year 1870. In the summer of that year the number of cases greatly increased, terminating in the following year in a severe epidemic which reached its climax in September and October. According to Felice del Agua,^[299] there were 1,287 cases and 152 deaths in the year 1870, and 4,467 cases and 866 deaths in the year 1871. In Rome small-pox made its appearance in October 1871, causing 335 deaths between October 10 and December 31, 1871, and 727 deaths in the entire year of 1872. In the case of a large number of individual places we have reports regarding epidemics of small-pox, but I was unable to find a comprehensive account of the epidemic that raged at that time in Italy.

(f) Great Britain and Ireland

Owing to the constant intercourse between England and France it was inevitable that small-pox should very soon be conveyed into England; the persons who conveyed it were probably French refugees. As on the continent, so also in England, small-pox was always prevalent; in the years 1869 and 1870, however, it was not very widespread, and it did not begin to gain much headway until the autumn of 1870. The number of deaths caused by small-pox in England was:

In the first nine months of the year 1870 there was no increase in the small-pox mortality, but in the last three months, and from January 1871 on, the increase was very marked. The number of deaths caused by the disease was:

These figures do not agree with the figures for the years 1870–1 given in the previous table, and the reason for this is not explained in the report. The places where the disease first entered England were London, Liverpool, and the mining districts of Durham and South Wales (Monmouth). The compiler of the reports regarding the movement of the population in England in the year 1871 says:^[300] ‘Nearly all the smaller outbreaks may be more or less directly traced to one of these centres; Brighton, for instance, doubtless suffered from its intimate communication with London. There is distinct evidence in many cases of the introduction of the disease into sea-side towns by sailors, and considering its fatal prevalence in Holland, Belgium, and many parts of France, it is not a matter for great surprise that Southampton, Great Grimsby, and one or two other ports suffered from the epidemic. It is indeed very probable that the epidemic in London was due to the large arrivals of French refugees during the latter part of the previous autumn. That the epidemic may to a great extent be traced to our foreign communications is beyond doubt, and it is to be regretted that the steady decline of deaths from small-pox in the six years 1864–9 had induced a certain apathy in the matter of vaccination, and thus left a large portion of the population unprotected from the disease. In times of severe epidemics large numbers of the vaccinated in some way or other also suffer for the neglect which has left so many unvaccinated.’

The number of deaths caused by small-pox in London was:

In the first quarter of the year 1871 some 2,400 persons succumbed to small-pox in London, in the second quarter 3,241, in the third quarter 1,255, and in the fourth quarter 980. The epidemic broke out in the East End of London in the fortieth week of the year 1870, i.e. in the first part of October; the number of deaths caused by it there was 40, and by the end of the year this number had increased to 110.

Of the English counties, those along the north-east coast were most severely attacked; for example, Durham and Northumberland, where the number of deaths caused by the disease was 45·0 and 29·8, respectively, per 10,000 inhabitants. In the cities of Sunderland and Newcastle-on-Tyne, located in these counties, the number of deaths per 10,000 inhabitants in the year 1871 was 86·0 and 54·1 respectively. There was a very large number of deaths in London (24·2 per 10,000 inhabitants), and the counties bordering on London (Middlesex and Essex) also suffered severely (9·3 and 8·0 respectively); next in order come the counties of Monmouthshire and Lancashire with 14·8 and 11·9 respectively. The high mortality in Lancashire was due only to the city of Lancaster, where there were no less than 38·8 deaths per 10,000 inhabitants; in the rest of the county the number of deaths per 10,000 inhabitants was only 6·3.

In Scotland and Ireland the number of deaths caused by small-pox was:

Small-pox spread very slowly to Scotland and Ireland; whereas in England the maximum number of persons died in the year 1871, in Scotland and Ireland the maximum number of deaths occurred in the year 1872. Both countries, moreover, were less severely attacked than England.

(g) Denmark, Norway, Sweden, Finland, and Russia

Small-pox was a long time in spreading to the Scandinavian countries. In Denmark an epidemic had raged in the year 1869, but did not become very widespread until the year 1872. In Copenhagen it began in the year 1871 and reached its climax in February 1872; between January and April 1,220 cases of the disease and 86 deaths were reported there. Regarding Norway we have no statistical information. In Sweden small-pox raged in the years 1865–9, abated a little in the years 1871–2, and started up again with considerable severity in the year 1873. Stockholm was severely attacked; in the year 1873 there were 13·0 deaths per 10,000 inhabitants, and in the following year 79·2. In Finland, where an epidemic had raged in the year 1868, the number of deaths caused by the disease began to increase in the year 1872, and in the two following years the epidemic acquired enormous dimensions. The number of deaths per 10,000 inhabitants was:

L. Colin reports that the pestilence spread to Russia in the year 1872, when it attacked St. Petersburg very severely. More detailed information I was unable to find.

(h) Non-European Countries

Constant emigration to America caused the disease to make its appearance there, and it gradually spread over the entire continent. The following table indicates the number of deaths caused by it in the states of Michigan and Massachusetts:^[296]

In New York 109 persons succumbed to small-pox in the year 1869, 293 in 1870, and 805 in 1871.

The disease was also conveyed to the West Indies and to Chile. Lersch,^[302] moreover, reports that severe epidemics of small-pox occurred in the Sandwich Islands and in Borneo, and that 500,000 persons succumbed to it in the years 1873–5 in British India. But inasmuch as small-pox frequently breaks out there in the form of large epidemics, it cannot be assumed that the epidemic in Europe exerted any influence upon this outbreak.

6. The Age of the Small-pox Patients. The Connexion between the Epidemic and the War. The German Imperial Vaccination Law

Thus far very little attention has been called to the fact that the age of the persons who succumbed to small-pox varied greatly in the different countries. This depends upon how well vaccinated the population of the country or countries was. Formerly, when nobody was ever vaccinated, the first year of life and the following years were by far the most seriously threatened; after the first few years the mortality of small-pox gradually decreased as the age of the patients increased. This also applies to-day to those countries in which vaccination is neglected. On the other hand, in those countries in which children are vaccinated in the first year of their lives, the infant mortality is low, although the same children lose their immunity to the disease when they grow older. To illuminate these facts let us adduce a few figures. In estimating the number of deaths, however, we cannot use the number of the living as a relative basis to work on, since the prevalence of small-pox varied greatly in the different countries; consequently we must take the total number of deaths and estimate the mortality on the basis of age from that alone. But in doing this we can compare with one another only entire countries in which the various ages are all about equally represented; if we were to take smaller units, for example, city and country, or agrarian and industrial districts, and use them for a basis of comparison, more detailed computations would be necessary. Of the four states included in the table below, Bavaria and Hesse introduced compulsory vaccination (the law required everybody to be vaccinated at least once) in the year 1807; Saxony and the Netherlands, on the other hand, did not have compulsory vaccination. Of every 100 persons who died of small-pox the following table indicates the relative proportion on the basis of age:

This table clearly shows that vaccination protects a person against contracting small-pox for a number of years, or at least against succumbing to it, but that this immunity lasts only for a certain length of time and should be prolonged by revaccination—a fact which the Prussian military authorities recognized and took into practical consideration for many decades prior to the year 1870.

Many have contended that the epidemic of small-pox which ravaged a large part of Europe, from the year 1870 on, was not a consequence of the Franco-German War, but an independent outcome of unknown conditions that were particularly favourable to the dissemination of the disease. The main argument used to uphold this contention is that epidemics of small-pox had occurred in all the states in the years before the war, without having gained such irresistible headway, and that the disease had broken out in the form of epidemics in many parts of Germany and the neighbouring countries even in the first half of the year 1870. But to refute this argument it can be clearly shown through Guttstadt’s instructive compilation of data that the German epidemic was in countless instances, in the case of Prussia as well as in that of other states in the German Confederation, brought about by the transplantation of the disease from France. Whenever small-pox broke out anywhere in times of peace, it was possible to keep the disease localized, through isolation of patients and the vaccination of the inhabitants of all regions in which fugitives from pestilence took refuge. In the year 1870, on the other hand, the contagion of small-pox was spread throughout all Germany in a few months; the increased intercourse caused by the war, together with the habit the Germans had of visiting the prisons where the French soldiers were confined, also helped to spread the disease in all directions.

For Germany this disastrous epidemic, which throughout the German Empire, including the Imperial Provinces, carried away upwards of 170,000 persons, had just one good result—it led to the passing of a law in the year 1874 which rendered vaccination compulsory. ‘Besides taking thousands of human lives the epidemic also caused considerable economic loss; the care of the sick and the measures adopted to prevent the disease from spreading necessitated large expenditures of money, while large numbers of working-men contracted the disease and were thus incapacitated for a long time; furthermore, the disease left unnumerable sickly people, who had to be further supported, and at the same time the fear of infection interfered with commercial intercourse. Those who managed to escape infection, or to recover from an attack of the disease, naturally wished to run no more risks in the future, or to expose the welfare of their families to danger or destruction.’^[303]

In consequence of all this grave suffering, the representatives of the people petitioned the Imperial Government to provide as soon as possible for a uniform legislative regulation, making universal vaccination compulsory. The desire expressed in this petition was soon fulfilled by the submission of a bill on February 5, 1874; the bill was passed by the Reichstag on March 14, and received the signature of the Kaiser on April 8, 1874. This law required all persons to be vaccinated in the first year of their lives, and to be revaccinated in their twelfth year; it applied generally to all Germany.

The beneficial result of the passing of this law was clearly demonstrated in the course of the following decades. Notwithstanding the fact that Germany is almost entirely surrounded by states in which epidemics of small-pox, in consequence of insufficient vaccination, are of frequent occurrence, since the passing of the Imperial Vaccination Law the disease has not once made its appearance on German soil in the form of a widespread epidemic. Despite the fact that small-pox is frequently conveyed into the country, especially by foreign working-men, the efforts to keep it confined within narrow limits have always been successful. The measures which are so effective in the case of other diseases—isolation of the patients and of suspected persons living in the vicinity, disinfection of the room and effects which have been used by patients—in an insufficiently vaccinated community do not have the desired rapid success, since the contagion of small-pox clings with extraordinary tenacity to clothes and articles of general use. This fact has been abundantly proved in the epidemics of small-pox that have occurred in Europe in the course of the last few decades.