1886.] 



MICROSCOPICAL JOURNAL. 



199 



is that the centre of gravity remains prac- 

 tically unchanged at any inclination of the 

 body, from horizontal to perpendicular. 

 The arm of the microscope forms a seg- 

 ment of a circle, and by means of a slid- 

 ing adjustment of this arm, the instrument 

 can be fixed at any inclination, with per- 

 fect stability in all positions. 



After the exhibition of various interest- 

 ing objects under the microscope, the 

 lecturer of the evening, Dr. Arning, was 

 introduced. He stated that he was about 

 returning to Europe, after sojourning for 

 a number of years in the Hawaiian Islands 

 for the express purpose of studying that 

 mysterous disease, leprosy. After allud- 

 ing to the difficulties surrounding- re- 

 searches of this kind in a comparatively 

 uncivilized country, far from the great 

 scientific centres, he said that while his 

 investigations had revealed many impor- 

 tant and interesting facts, yet in some re- 

 spects his attempts had been baffled. A 

 long search for a possible source of dis- 

 semination of the germ of leprosy in food, 

 water, etc., was unsuccessful. The dis- 

 tinctive micro-organism of leprosy is a 

 minute , red-like fungus — Bacillus lepra". 

 Hansen, a Norwegian investigator, seems 

 to have been the first to discover this bacil- 

 lus. He found it abundantly in leprous tu- 

 bercles, and announced the fact in 1879. 

 Since that time Neisser, Koch, Unna, and 

 others have confirmed and extended 

 the observations of Hansen. These 

 bacilli are slender, non-motile rods, about 

 half as long as the diameter of a human 

 red corpuscle. In uncolored sections 

 they are nearly or quite invisible, even 

 under high amplifications, but where 

 appropriate staining processes are em- 

 ployed they can be rendered beautifully 

 distinct. In form and size they very 

 closely resemble the bacillus of consump- 

 tion (^Bacillus ti(bcrciilosis) — so closely 

 indeed, that the distinction by mere in- 

 spection is by no means easily made. 

 The color reaction is also remarkably 

 similar. The last-named organism, how- 

 ever, can be successfully 'cultivated,' 

 while all of Dr. Arning's attempts to ob- 

 tain a ' pure culture ' of Bacillus leprce 

 met with failure, although in his experi- 

 ments he employed every known culture 

 medium, and tried some not hitherto 

 used, such as the favorite native dish' 

 'poi.' Not even on excised tubercle 

 would the bacilli flourish. Finally, al- 

 most by accident, he obtained a compar- 

 atively pure growth of the desired organ- 

 ism. A small piece of excised tubercle 

 from the chin of a leper had been 



placed in a small glass vessel for macera- 

 tion. After an absence of nearly eight 

 months Dr. Arning examined the prepar- 

 ation (which had in the meantime been 

 kept supplied with water by his laboratory 

 assistant) and found a gray scum on the 

 surface of the water. The bottom of the 

 glass vessel was covered with a detritus, 

 consisting of micrococci, putrefactive bac- 

 teria and other fungi. The scum was 

 found to consist almost entirely of aggre- 

 gated masses (Zooglcea) of a bacillus, 

 which Dr. Arning feels justified in stating 

 was undoubtedly Bacillus leprcE, although 

 the rods were slightly shorter than usual. 

 Upon attempting to continue the culture 

 of a portion of this scum in water, an 

 attenuated growth, still comparatively 

 pure, was obtained. At this interesting 

 juncture Dr. Arning's experiments were 

 mterrupted by reason of his departure 

 for Europe, but he hopes to be able to 

 resume them before long. 



It has been a disputed point as to 

 whether or not the bacilli of leprosy grow 

 inside of cells. That they do so has 

 been denied by Unna, but some beautiful 

 double-stained preparations made by Dr. 

 Arning seem to demonstrate beyond all 

 possible doubt that such is at least a fre- 

 quent, even if not the invariable, method 

 of growth. Dr. Arning further stated 

 that in the anaesthetic red patches pecu- 

 liar to this disease no bacilli had been 

 found. Neither did they appear in the 

 sores due to the killing of the nerves 

 leading to those points, while in the 

 tuberculous patches large numbers of free 

 bacilli were always found. From these 

 and other indications he inclines to the 

 opinion that the disease is propagated by 

 the accumulation of bacilli in the large 

 nerve trunks. In the blood of leprous 

 patients these organisms are not found. 



In the internal organs of the victims of 

 this disease great changes are found. 

 Lepers are often booked as having died 

 of consumption. In many such cases 

 Dr. Arning is convinced that the break- 

 ing down of the lung structure is due to 

 the ravages not of Baccillus tuberculosis, 

 but of B. leprcp. In tuberculous con- 

 sumption, the bacilli are originally found 

 in the ' giant cells,' but in leprosy there 

 are no such cells. Another point of dif- 

 ference is that there is seldom or never 

 any hemorrhage of the lungs in leprous 

 patients. After alluding to the presence 

 and describing the appearance of the 

 bacilli in the spleen, kidneys, and other 

 organs of lepers. Dr. Arning stated that 

 in the present state of knowledge on the 



