II. THE CHRONIC INFLAMMATORY DISEASES. 



CHAPTER I. 

 TUBERCULOSIS. 



TUBERCULOSIS is one of the most dreadful and, un- 

 fortunately, most common diseases of mankind. It affects 

 alike the young and the old, the rich and the poor, the 

 male and the female, the enlightened and the savage. 

 Nor do its ravages cease with human beings, for it is 

 common among animals, occurring with great frequency 

 among cattle, less frequently among goats and hogs, and 

 sometimes, though rarely, among sheep, horses, dogs, 

 and cats. 



Wild animals under natural conditions seem to escape 

 the disease, but when caged and kept in zoological gar- 

 dens even the most resistant of them lions, tigers, etc. 

 are said at times to succumb to it, while it is the most 

 common cause of death among captive monkeys. 



The disease is not even limited to mammals, but occurs 

 in a somewhat modified form in birds, and, it is said, 

 even at times affects reptiles. 



It is not a disease of modern times, but one which has 

 persisted through centuries ; and though, before the ad- 

 vent of the microscope, not always clearly separated 

 from cancer, it has not only left unmistakable signs of 

 its existence in the early literature of medicine, but has 

 also imprinted itself upon the statute-books of some 

 countries, as Naples, where its ravages were great and 

 the means taken for its prevention radical. 



While the great men of the early days of pathology 

 clearly saw that the time must come when the parasitic 



169 



