CULTIVATION OF LEPROSY BACILLUS 307 



both, cultural characters and pathogenic effects, with the organism 

 obtained from the human disease. 



Nastin. — This substance has been pretty extensively used in the treat- 

 ment of leprosy and certain favourable effects have, been recorded. It is 

 a crystallisable neutral fat, composed of a high molecular fatty acid and 

 glycerin, and was extracted by Deycke and Reschad by means of ether 

 and alkaline alcohol from an acid-fast streptothrix obtained from a case of 

 leprosy (the relation of this organism to the "bacillus of leprosy " is still 

 doubtful). It is usually given as a mixture with benzoyl chloride and is 

 said to give a specific reaction on injection into lepers. Much considers that 

 "nastin"is a substance common to various acid-fast bacteria and capable 

 of stimulating the formation of anti-substances to these organisms. Wills 

 takes a somewhat similar view, holding that there are definite substances 

 of the fatty group common to acid-fast bacteria which are capable of 

 functioning as antigens. If this view is correct, the occurrence of a 

 reaction on the injection of a given acid-fast organism, or of its products, 

 into a leper will be devoid of specific significance as regards the relation 

 of that organism to the disease. 



It would also appear that the disease is not readily inoculable 

 in the human subject. In a well-known case described by Arning, 

 a criminal in the Sandwich Islands was inoculated m several 

 parts of the body with leprosy tissue. Two or three years later, 

 well-marked tubercular leprosy appeared, and led to a fatal result. 

 This experiment, however, is open to the objection that the 

 individual before inoculation had been exposed to infection in a 

 natural way, having been frequently in contact with lepers." In 

 other cases, inoculation experiments on healthy subjects and 

 inoculations in other parts of leprous individuals have given 

 negative results. It has been supposed by some that the failure 

 to obtain cultures and to reproduce the disease experimentally 

 may be partly due to the bacilli in the tissues being dead. The 

 varying results of inoculation of the human subject present, to 

 an extent, a parallel to the results of experiments on animals, as 

 given above. 



The facts stated with regard to cultivation and inoculation 

 experiments go to distinguish the leprosy bacillus all the more 

 strongly from other organisms. Some have supposed that leprosy 

 is a form of tubercle, or tubercle modified in some way, but for 

 this there appears to us to be no evidence. It should also be 

 mentioned that tubercle is a not uncommon complication in 

 leprous subjects, in which case it presents the ordinary characters. 

 It has been found that a considerable proportion of lepers react 

 to tuberculin like tubercular patients. This result has been 

 variously interpreted, some considering that tuberculosis is also 

 present in such cases, whilst others maintain that the reaction 

 may be given in the absence of tubercle. If, as is probable, the 



