6 THE PRESIDENTIAL ADDRESS. 
micrococeus, but, as they showed no rise of temperature or any signs 
whatever of ill-health, they were put aside as being immune or refractory 
to the disease and nothing more was thought about them. 
In the spring of 1905, about six months after these experiments had 
been made, Dr. Zammit, a Maltese member of the Commission, who had 
kept one of two of these goats, happened for some reason or other to 
examine their blood, and found that it clumped or agglutinated the micro- 
coccus. This was strange, and seemed to show that, although the micro- 
coccus had not caused fever or any signs of illness in the goats, it must have 
lived and multiplied in the tissues of these animals in order to have brought 
about this change in the blood. 
This observation led to the re-examination of the immunity of the goat, 
when the extraordinary discovery was made that about 50 per cent. of the 
goats in the island were affected by this disease, and that 10 per cent. of 
them were actually excreting the micrococcus of Malta fever in their milk, 
Monkeys fed on milk from an affected goat, even for one day, almost 
invariably took the disease. 
Thus the weak link in the chain of causation had been found. The 
military authorities struck Maltese milk out of the dietary, and replaced 
it by an imported variety, and from that day to this there has scarcely 
been a case of Malta fever in the garrison. Malta, from being the most 
unhealthy of foreign stations, became a health resort, and was in fact 
used as a sanatorium during the late war. The disease had been blotted 
out at a single blow. 
This, then, is one way of preventing an infectious disease ; that is to 
say, by the discovery of the living germ, the study of its natural history, 
and so to a means of stopping it reaching its victim, man. This is the best 
way of prevention : shutting the stable door before the horse is stolen. 
Typhoid Fever. 
But there are other ways of preventing bacterial diseases. Let us take, 
for example, a method widely used in the prevention of typhoid fever. 
The fundamental and sound way of attacking this disease is by 
ordinary hygienic measures, especially a good water supply and good 
drainage. It is therefore one of the first duties of those in power to see that 
their people have, in addition to houses with plenty of light and air, a good 
water supply and a good drainage system, and money cannot be spent to 
better advantage than in the attainment of these three essentials to health. 
When typhoid fever is rife in a community it means that there is 
