CHAPTEK XXVIII. 



TUBERCULOSIS DISTRIBUTION AMONG MAN AND ANIMALS- 

 ROUTES OF INFECTION. 



THE term tuberculosis is derived from the Latin word tuberculum, 

 the diminutive of tuber, which means a knob, protuberance, or nodule. 

 It is a very widespread disease among man and some of the domestic 

 animals, particularly cattle and swine, and is characterized anatom- 

 ically by the formation of poorly vascularized or avascular nodules, 

 which have a tendency to become caseous. The disease in all of its 

 forms is due to a specific organism known as the tubercle bacillus of 

 Robert Koch. 



Historical Remarks. The pulmonary form of tuberculosis of man 

 is also termed consumption, or phthisis, i. e., a consuming or wasting 

 away, and has been known to mankind for thousands of years. A 

 vivid description of the disease is found in the works of Hippocrates, 

 but it would hardly have enabled the Father of Medicine to pass a 

 very creditable examination as to etiology and morbid anatomy. 

 Hippocrates 1 distinguished three forms of pulmonary tuberculosis 

 in man, and his description is so highly interesting that a few passages 

 from it will not be out of place. He says: "There are three kinds 

 of pulmonary consumption. The first kind is due to mucus. If the 

 head, filled with mucus, becomes diseased and heated the mucus in 

 the head becomes putrid because it cannot be removed properly. 

 After the mucus has become condensed and putrid, and after the 

 bloodvessels have become overfilled with it, a flow toward the lungs 

 is established, and as soon as the lungs contain this mucus they become 

 corroded because the latter is salty and turbid. The patient now 

 experiences a mild fever, with chills, the chest and the back are 

 painful, he is tortured by a violent cough, and he coughs up large 

 masses of a moist, salty sputum. This is what he experienced in 

 the beginning of the disease, and in its farther course the body wastes, 

 with the exception of the legs, which swell up, also the feet swell, and 

 """" Hthe nails become contracted. He becomes lean around the shoulders, 

 the larynx becomes filled with a kind of foam, and the breath whistles 

 like the air in a reed. During the disease the patient has great thirst; 

 he becomes very weak.f If he is in this conditioners a rule,\he perishes 

 Q miserably from the wasting away within a year. 



1 The quotations are taken from the German translation of Hippocrates' works, by Robert 

 Fuchs, Munich, 1897, vol. ii, chap, x, p. 494 et seq. 



