BACILLUS OF LEPROSY. 211 



found enclosed in the leucocytes in the intestines, lungs, and 

 in the sputum. 



The leprous nodule or tubercle differs from the genuine tuber- 

 cle in that it is vascular and contains much fibrous tissue. 

 The bacillus is enclosed within large cells, which have been 

 called lepra-cells. They resemble a tubercular giant cell in 

 size, but are not always multinucleated. The ulceration 

 appears to be due rather to the poor vitality of the tissue 

 than to any action of the bacillus. In the anaesthetic form 

 of leprosy the nodules are located on the peripheral nerves, 

 and the formation of fibrous tissue is responsible for the sub- 

 sequent anesthesia. The various skin lesions occurring in 

 this form are always the result of injury. Burns are very 

 common because of the anaesthesia. 



Arning inoculated a condemned criminal, who was perfectly 

 healthy, with leprous material, and in five years the disease 

 was fully developed. Other attempts to infect healthy indi- 

 viduals have failed. It is believed that leprosy is contagious 

 in the same sense that tuberculosis is contagious ; and, there- 

 fore, that contact is probably not so much a source of infec- 

 tion as was formerly supposed. 



Baumgarten is of the opinion that it is also inherited, and 

 cases have been reported in which that assumption seems to 

 be the only explanation for the occurrence of the disease. 

 Opposed to this view is the fact that leprosy is never known 

 to occur in infants. 



Individual susceptibility is an important factor. Persons 

 who have been in contact with lepers for years have not con- 

 tracted the disease. Sexual intercourse appears to be a very 

 common method of infection in leprosy. 



Diagnosis: Preparations made from the serum obtained 

 from a leprous nodule are stained in the same manner as for 

 tubercle bacilli. The lepra bacillus is always found in great 

 numbers, which serves to differentiate it from the tubercle 

 bacillus. The nasal mucus always contains lepra bacilli. The 

 serum of a leprous patient will agglutinate the bacilli in dilu- 

 tions of 1 : 60. Leprous patients usually die from exhaustion 

 or some intercurrent affection, especially inhalation pneumonia. 



Distribution: Although leprosy is commonly believed to be 



