DISCOVERY OF THE CAUSE 223 



to 1905 the average yearly incidence was 37 "G per 

 thousand. In the year 1905 as many as 403 officers 

 and men were invaUded home, and in previous years 

 the numbers were also uniformly high. The average 

 stay of the soldiers and sailors in hospital in JNIalta 

 was 90 days, and say a further 120 days' stay in 

 hospital when invalided home ; therefore on an average 

 624 soldiers and sailors were in hospital 120 days 

 each, making up a total of 74,880 days of illness." 

 Bruce adds, " What the amount of personal suffering 

 and loss to the State this sickness and invaliding 

 entailed it is impossible to estimate, but the mere 

 pecuniary loss must have been very considerable." 



Discovery of the Virus. — This was found by Bruce 

 to be a micrococcus — the Micrococcus melitensis. Its 

 presence is demonstrable in all persons suffering from 

 the fever. 



Discovery of the Source of Infection. — Suspicion 

 fastened upon the goats, which were very plentiful 

 and were the source of the milk supply. Examina- 

 tion of these animals revealed the fact that 50 per 

 cent, of them contained the parasite, although appearing 

 to be perfectly healthy, and in 10 per cent, of them 

 the milk contained the micrococcus. Here then was 

 a magnificent example of so-called " healthy carriers " 

 of the disease, in this case in the animal. 



As happened in the case of other infectious pro- 

 cesses in man, so here an accidental infection in man 

 gave the final proof. In 1905 a steamer sailing to 

 the States shipped Q5 goats from IMalta ; their milk 

 was consumed by the captain and many of the crew, 



