■iOO SANITARY CONDITIONS 



anesthesia, paralysis of the muscles and trophic disturbances. In the early 

 stages the patient complains of pains along the nerves, and patches occur on the 

 skin of considerable size, the margins of which show a congestion. Later 

 these patches become pale in the center but the margins remain pigmented. 

 After a time remarkable trophic changes appear in the skin, muscle and bones. 

 The skin becomes atrophied like parchment and skin eruptions as hullce, 

 etc., as in pemphigus, often appear. Great distortion of the extremities may 

 occur with necrosis and separation of parts. The lesions in the nerves are of a 

 chronic inflammatory nature but with less granulation tissue t4ian in the case 

 of tubercular leprosy. This is probably due to the fact that fewer bacilli are 

 found in the anesthetic type. (Plate LXXI.) 



Bacillus of Leprosy. 



The bacillus of leprosy was observed first in leprous tissues by Hanson 

 in 1871, and further researches were made by Neisser in 1879. This bacillus 

 has not with certainty been grown artificially, although recently Dr. L. Alvarez 

 believes he has gotten slight growths on blood serum. The leprous bacilli are 

 practically the same size as the tubercle bacilli and resemble them both 

 in appearance and staining reactions. They take up the basic aniline stains 

 rather more readily than the latter, but in order to stain them deeply a powerful 

 stain such as carbol-fuchsin is necessary. They resist discolorization, but less 

 so than the tubercle bacilli, as it requires but about 5 per cent sulphuric 

 acid solution to remove the carbol-fuchsin. The best method of staining them is 

 to use the Ziehl-Neelson carbol-fuchsin stain, and then Gabbet's methylene 

 blue solution with only one-half the strength of sulphuric acid in this 

 solution as is used in staining the tubercle bacilli. Dr. Alvarez never suc- 

 ceeded in finding decolorized bacilli in old tubercles or ulcerations. They 

 were found only in recent eruptions or nodules and are probably the young 

 or active bacilli, while the bacilli which hold the stam are probably old and 

 inert. He states that this discovery may serve to explain the many failures 

 in producing evidences of culture on artificial media 



Dr. Arning who conducted numerous experiments relative to the resisting 

 power of the leper bacillus in tissues showed that it resisted the extreme con- 

 ditions of temperature and moisture conducive to the development of ]mtre- 

 faclion, even when put aside for a considerable length of time."" 



^ Report on Leprosy in the Hawaiian Islands, Nov. 29, 1898. Letter from 

 the Surgeon-General of the Marine Hospital Service, etc. Senate Doc. No. 269, 

 57th Cong., 1st session, pp. 106-107. Reprinted from Public Health Reports, Decem- 

 ber .30, 1898. 



