TUBERCULOSIS. 221 



There seems, in these cases, to be, first, a weakened con-/^ 

 dition and impaired power of resistance of the epithelial 

 cells lining the small bronchi, the smaller air passages and 

 the air vesicles making up the spongy tissue of the/ 

 lung. The bacilli in the air and dust then finding their way 

 to a surface already weakened and specially prepared as it 

 were for their reception, recommence their parasitic life, 

 multiply, and make their way further into the tissues, where 

 they set up the changes associated with tubercular disease. 

 It is evident from all this that much work still lies ready 

 to our hand in connection with the spread of tubercle, 

 and that if we could only persuade people to look upon 

 tubercle as an infectious disease similar in character to 

 scarlet fever, though not so rapidly developed, much 

 would have been done to prevent its spread, and a great 

 advance in preventive medicine would have been made. 

 Through the work of Koch, Cornet, and others, the Ger- 

 mans have come to look upon perfect cleanliness in the 

 treatment of phthisical patients as absolutely essential. 

 Pocket handkerchiefs and bed linen used by phthisical 

 patients are most carefully sterilized by means of bichloride 

 of mercury, hot air, steam, or other germicidal agents ; 

 patients are strongly enjoined not to expectorate except into 

 receptacles specially made for the purpose, receptacles that 

 can be carried about, can be most readily cleaned, and in 

 which expectorations can be easily disinfected. Of course, 

 the results of all this are not yet manifest, but it may be 

 confidently anticipated that within a comparatively short 

 time a considerable diminution in the number of phthisical 

 patients in Germany will have to be recorded ; not to be 

 compared, perhaps, with the diminution of cases of other 

 diseases, but still a very appreciable one. 



As a single example we may take the Grand Duchy of Baden, where 

 there was a diminution of deaths from tuberculosis from 3.08 per 1,000 

 inhabitants in 1882 to 2.80 per 1,000 in 1887, or no less than .28 per 

 1,000. Were this to be equalled in the British Isles, and the patients were 

 not carried off by other diseases, the saving to our community would be 

 nearly 10,000 lives per annum. 



We may here mention the various disinfectants used. By far the best is 

 heat, especially moist heat. Sunlight, or even ordinary daylight, will, ac- 

 cording to Koch, kill tubercle bacilli in from a few minutes to five or six days. 

 Koch has also proved that a number of ethereal oils, some of the so-called 

 aniline or tar dyes, mercury in the form of vapour and silver and gold com- 



