(d) In America.-With the exception of Mr. Thompson, who died in January, 1906, from "bilateral pneumonia following influenza," and about whose medical history, qua Mediterranean fever, no evidence can be obtained, only 1 person-a woman at the quarantine station-took the milk in any quantity. She, however, drank the mixed milk from several goats for a considerable period, and in December, 1905, suffered from a typical attack of Mediterranean fever.

3. THE RESULTS.

In summarizing the result of this unpremeditated experiment several factors have to be considered. For instance, a certain unknown number of goats-more, however, than 2-were shown to be secreting infective milk after their arrival in America, some three months after leaving Malta, but there is no direct evidence as to the number whose milk contained M. melitensis during the voyage in summer weather from Malta to Antwerp. Arguing from analogy with average Maltese herds, at least 6 should have been secreting infective milk. The goats purchased by Mr. Thompson were, however, picked animals and heavy milkers, and as experience has shown that the goats yielding the most milk in any given herd are the most likely to be passing M. melitensis in their milk, the probability is that in this particular herd of 60 milch goats (1 having died the day after leaving Malta) the milk from considerably more than 6 was heavily infected— an inference which receives confirmation from the fact that the 3 officers and the steward who drank "mixed" milk each developed an attack of Meditterranean fever, the remaining officer and the cabin boy, with whom the milk disagreed and who consequently did not. drink it, remained well.

The members of the crew, on the other hand, each drank "whole " milk from a single goat, and apart from the possibilities of the milk being supplied on any particular occasion from an uninfected animal, a reference to Section I (3), shows clearly the possibilities of a man who obtains milk, even from an infected animal, avoiding the ingestion of infective milk.

Apart from such considerations, however, it suffices to state the net result as follows:

a

Of 23 men on board the steamship Joshua Nicholson who drank on one or more occasions presumably infected milk, no evidence whatever is available as to 12 and no relevant information as to Mr. Thompson; of the remaining 10, 1 suffered from hernia only, 1 was infected by M.melitensis at an unknown date, while 8 suffered

"That is disregarding the 2 men who boiled the milk before drinking it, and the officer and cabin boy who did not drink the milk.

from febrile attacks 5 (or 50 per cent of them) yielding conclusive evidence of infection by M. melitensis.

In Report No. 5 of the commission is an article by Major Horroks on Mediterranean fever in Gibraltar. The facts there detailed, taken with the curve showing the relation of the number of goats in

1884 85 86 87 88 89 90 91 92 93 94 95 96 97 198 199 1900'01 02 03 04 05

Gibraltar to the number of cases of Malta fever, is particularly interesting and suggestive. With the reduction in the number of goats in Gibraltar there was also a decrease in the number of cases of Malta fever, so that finally when the number of goats had decreased to about 200 in 1905, Malta fever has practically disappeared.

a

Mediterranean fever, often called "rock fever," has existed in Gibraltar for many years, although the cause of the fever was not known until the discovery of Bruce's specific organism from fatal cases of Malta fever. Physicians residing in Gibraltar knew of the existence of a fever characterized by long duration, low mortality, and liable to be followed by rheumatic sequela.

In a study of the cases of continued fever in Gibraltar from 1882 to 1905 it was shown by Horrocks that in the year 1884 there were 833 cases of continued fever of which 429 were probably Mediterranean. In 1885 there were 697 cases of continued fever including 341 cases of Malta fever. In 1886 there were only 331 cases of continued fever and of these 158 were enteric fever. The great increase in the number of cases of enteric fever was attributed partly to the arrival of an infected regiment in Gibraltar from Egypt and to serious sanitary defects in Gibraltar. In 1887 there was again a considerable falling off in the number of cases of Mediterranean fever and from that date, with slight oscillations, the curve of Mediterranean fever gradually declined until it reached 0 in 1904. The rapid disappearance of febrile diseases from Gibraltar, which commenced in 1885, forms a marked contrast with the state of things in Malta in corresponding years. It is plain that some important factor which disappeared from Gibraltar has continued to operate in Malta.

It has been shown that the M. melitensis is excreted in the urine of man and goats and that animals can be infected by dust contaminated with the urine of Malta fever patients; that the micrococcus is excreted in the milk of infected goats, and that the consumption of this milk causes Malta fever in monkeys. It is evident that both the sanitary conditions and the possible infection of goats in Gibraltar must be investigated if the cause of the continued fever is to be discovered.

That the improvement of the sanitary conditions played but a minor part in the marked decrease in the prevalence of Malta fever in Gibraltar is shown by the fact that the curve representing the presence of Malta fever among the military population rose steadily from 1874 to 1884, in spite of the improvement in the sanitary conditions in Gibraltar.

Twenty years ago goats were allowed to graze on certain portions of the rock and passes were granted to goat keepers for this privilege. In 1883 passes for 1,793 goats were granted. In 1886 the number of passes had been reduced to 1,512; by 1890 the passes had further declined to 590, and in 1892 to only 510. From 1894 to 1902 the number of goats appears to have changed very little; in 1904 the a Reports of the commission for the investigation of Mediterranean

passes were reduced to 210, and when Major Horrocks began an examination of the goats in 1905 he found only 254 distributed upon various portions of the rock. It might be urged that, though passes for grazing were withdrawn, the goats were still kept and housed in goat sheds. This, however, was not the case, as Major Horrocks ascertained that in the period from 1883 to 1903 about 1,100 goats had been sold, and those familiar with the goat trade stated that where passes for grazing could not be obtained the goats were not kept in any numbers.

In 1905, Major Horrocks took specimens of blood from 254 goats found on various portions of the rock and tested the serum for agglutination. Fourteen per cent of them gave a positive reaction with M. melitensis. It is extremely suggestive that the decrease in the Malta fever in the military population was coincident with the decrease in the number of goats in Gibraltar.

It appears probable that the rapid disappearance of Mediterranean fever from Gibraltar, which commenced in 1885, was intimately associated with the exodus of infected goats from the rock. Improved sanitary conditions, especially the disconnection of waste pipes and house drains from sewers, may have played a part in causing the decrease of fever, but as the same sanitary improvements have been carried out in Malta without any corresponding decline of Mediterranean fever, it is fair to assume that their effect was insignificant compared with that produced by the removal of the infected goats.