250 TUBKKCULUSIS. 



one to every ten men, and these had, been selected, heal- 

 thy men. In 1874 this high death rate from consump- 

 tion had been reduced in the army to less than 10 to 

 1,000, and in 1883 it was 6 to 1,000. At the present time 

 it is still further reduced. Up to 1882. when Koch's 

 great discovery and positive demonstration of the bacil- 

 lus tuberculosis as the "causa vera" of consumption, there 

 had been no end of learned and elaborate theories as to 

 the origin and nature of tubercle. 



All these surmises are now of interest mainly as mat- 

 ters of history. Scrofula and phthisis have also been 

 shown to be due to one and the same cause, and lupus 

 is recognized as a tubercular disease of the skin. Besides 

 Koch there were many observers on the lookout for spe- 

 cific organisms, especially Chauvau, Baumgarten and 

 Zeigler. I have said that lupus and scrofula are believed 

 to be identical with tuberculosis, and there is another im- 

 portant disease which very closely resembles it, and that is 

 leprosy. In their pathology, in their course and distri- 

 bution, and in many other features these diseases show 

 the closest relationship. A micro-organism is closely 

 associated with each disease, and the bacillus of leprosy 

 is so similar in appearance and in its reception of stain- 

 ing fluids that the most accomplished bacteriologists can 

 find little or no difference in appearance between it and 

 the bacillus of tubercle. Differences in action, however, 

 exist, for the bacilli of lepra exist in much larger pro- 

 portion than those of tubercle in diseased tissues. Lep- 

 rosy has never been produced by inoculation and pure 

 cultivations of lepra bacillus cannot be obtained. It is 

 probable that leprosy was even more prevalent during 

 the middle ages than phthisis is even now. Daring the 

 reign of Louis YIII it is known that in France alone there 

 were no less than 2,000 leper hospitals endowed by his 

 will, and that throughout France, England, Germany 

 and Italy there was no less than 19,000 of these asylums. 



188 



