COMMUNICABLE DISEASES. 205 



Irrational diet, drink and food fads, sooner or later leave their pernicious 

 effects upon the system and predispose to certain diseases. Overeating 

 is as objectionable as starvation. Lack of adequate physical exercise has 

 its evil effects as does also over-exerdon. Trained or professional athletes 



/S i> / / 





Fig. 78. Fig. 79. 



Fig. 78. — Bacillus mallei, the cause of glanders in horses. This disease can be trans- 

 mitted to man where it causes symptoms of a suppurative infection of the lymphatic glands. 

 Mallein, which is used in testing horses for glanders, consists of the filtrate (Berkefeld 

 filter) of dead cultures (glycerin bouillon) of the bacillus. A positive maUeiu reaction 

 consists in a rise in temperature and local swelling. The dose is i c.c. 



Fig. 79. — Bacillus tetani, an anaerobic spore-bearing bacillus, the cause of tetanus or 

 lockjaw. This bacillus is found in soils and may infect abrasions, cuts and wounds. 

 Treatment with tetanic antitoxin is successful if begun before the symptoms develop. The 

 best time to administer the antitoxin is at the time the injury is received. 





y^ 



Fig. 80.— a spore-bearing bacillus stained with methyl blue leaving the spores unstained. 

 Fortunately most of the bacilli pathogenic to man do not bear spores. 



are not long lived, many are hopelessly afficted with enlarged and weakened 

 heart and arteries (aneurism). Pernicious habits of all kinds indicate 

 weakness and further develop the weakness, which in turn predisposes to 

 certain diseases and render the individual less resistant to the ravages of 

 disease. A good ancestry and inheritance, good wholesome food, comfort- 



