PLAGUE IN INDIA. 313 



bii}' nine years ago was a surprise ; but the greatest surprise of all, in 

 a historical sense, has been the endemic settlement of the infection in 

 J he plains. This is, indeed, a real novelty of the present situation to 

 epidemiologists, as well as a very serious practical matter ; but for the 

 rest plague is a very ancient disease, and, I take leave to say, very 

 well known in its type and in its habits to those who are competent in 

 such matters. There is just as little mystery about plague and just 

 as much as there is about cholera, or yellow fever, or typhus, or en- 

 teric, and there is actually less mystery about it than about those 

 everyday domestic incidents, measles and scarlatina. What, then, 

 is the meaning of the claptrap about "our ignorance of plague?" 

 So far as I can understand it has arisen from the fashion which the 

 public and the newspapers have adopted of thinking bacterially about 

 diseases. Bacteriologists, when asked to explain plague, are found 

 to be not so lucid as usual. They are at fault in the pursuit of the 

 bacillus outside the body. It runs to earth and gets lost in a crowed 

 of other bacteria in the soil, or disguises itself as a saprophytic mold, 

 or perishes outright in the struggle for existence, although there is 

 no doubt about the infection remaining in the ground all the same. 

 Hence, perhaps, the impression that more bacteriology is necessary 

 before an3'thing practical can be done. 



RECENT SCIENTIFIC DEVELGPINIENTS. 



As plague is not found to be contagious from person to person 

 except in its pneumonic variety, everyone sees that the interest must 

 center in the infection outside the body. In that connection research 

 in India has added only two novelties to the older body of doctrine, 

 both of them of the minor kind. Xo one can deny, although some 

 would if they could, that the regular way of receiving the infection of 

 plague is by the breath ; but inasmuch as rats in a laboratory can be 

 made to take plague, or something like it, by inserting a culture of 

 bacilli at a puncture of the skin, so it is sought to prove that there 

 ma}^ be something corresponding in human ex})erience. One theory 

 started in India is that the infection may enter through wouuds 

 of the feet, as the people of that country so often uncover their feet 

 ceremonially and so many of them go barefoot for want of shoes. 

 This theory is of course inapi^licable to European plague, for exam- 

 ple, the great plague of London in 1605. But there is another theory 

 devised to give moral support to the inoculation experiment on rats, 

 Avhich implicates the rat himself; it is that the fleas which infest 

 the rat may introduce infection through flea bites on the human skin. 

 The Austrian plague connnission, which was the first in the field at 

 Bombay in 1897, had already considered whether mosquitoes might 

 sM 1905 24 



