288 BACTERIA 



But personal hygiene and the prevention of the transmission 

 of the disease depend very largely indeed upon the mass of 

 the population. Hence we hail with satisfaction the recent 

 endeavours to educate public opinion. In order to make 

 this matter very simple indeed, we have placed in a footnote 

 a series of statements embodying some of the chief facts 

 which every individual in our crowded communities should 

 know. 1 



1 i. Tuberculosis is a disease mainly affecting the lungs (consumption, decline, 

 phthisis) of young adults and the bowels of infants (tabes mesentericd). It may 

 affect any part of the body, and its manifestations are very various. It also 

 affects animals, particularly cattle, by whom it may be transmitted to man. 



2. Its direct cause is a microscopic vegetable cell, known as the Bacilhis 

 tuberculosis, discovered by Koch in 1882. This fungus requires to be magni- 

 fied some hundreds of times before it can even be seen. When it gains entrance 

 to the weakened body it sets up the disease, which is an infectious disease, 

 though different in degree to the infectiousness of, say, measles. 



3. Trade influence and occupation, in some cases, undoubtedly predispose 

 the individual to tubercle. Cramped attitudes, exposure to dampness or cold, 

 ill ventilation, and exposure to inhalation of dust of various kinds, all act in 

 this way. In support of the evil effect of each of these four conditions much 

 evidence could be produced. 



4. Overcrowding has a definite influence in propagating tubercular diseases. 

 The agricultural counties without big towns, like Worcestershire, Hereford- 

 shire, Buckinghamshire, and Rutland, are the counties having the lowest mor- 

 tality from tuberculosis ; whilst the crowded populations in Northumberland, 

 South Wales, Lancashire, London, and the West Riding suffer most. Speaking 

 more particularly, the overcrowded areas of London, such as St. Giles', 

 Strand, Holborn, and Central London generally, show very high tubercular 

 death-rates. 



5. Tuberculosis is not increasing. During the last thirty years it has shown, 

 with few exceptions, a steady decline in all parts of England. " Consumption " 

 is most fatal in comparatively young people (fifteen to forty-five years), whilst 

 " tabes " and other forms of tubercle are fatal chiefly to young children. These 

 forms have not declined so much as the lung form. The mortality in con- 

 sumption of males has since 1866 been in excess of that of females. The age 

 of maximum fatality from consumption is later than in the past, which is 

 probably due to improved hygiene and treatment. 



6. This decline has been due, not to any special repressive measures for few 

 or none have been carried out but to a general and extensive social improve- 

 ment in the life of the people, to an increase of knowledge respecting tubercu- 



