216 BIOLOGICAL PROBLEMS 



Repeated experiments of the same nature gave iden- 

 tical results, and it seemed therefore that we had laid 

 our hands upon the vital factor in the success of salt- 

 pack treatment, namely, the fostering of a particular 

 anaerobic bacillus in the wound. All the same, it was 

 still uncertain what part the salt played in the matter, 

 and how far its lymphagogic action was responsible 

 for the results; also whether the repacking process 

 had itself an influence. This was determined by 

 eliminating salt altogether in certain test cases, and 

 substituting inert packs in the first instance, employ- 

 ing either sphagnum moss or simply plain white 

 gauze. The results were identical in the process of 

 recovery with the normal salt-bag treatment. Now 

 we are in a position to say that the lymphagogic ex- 

 planation of salt treatment is at least unnecessary, for 

 identical results can be obtained with a perfectly inert 

 dressing, provided that our proteolytic bacillus be 

 present. The bacillus alone appears to be the cura- 

 tive agent, and this in spite of its association as an 

 anaerobe in the same class with several of the most 

 virulent of organisms, e.g. Bacillus tetani and B. per- 

 fringens ; and the just fear that has ever attended infec- 

 tion with any anaerobic bacteria. However, the whole 

 classification and segregation of anaerobes is still so 

 chaotic that it is easy to believe that very deep dis- 

 tinctions may underlie superficial similarities, as is 

 apparently the case here. 



There does not appear to be any obligatory relation- 

 ship between the Reading bacillus and the salt, nor 

 has it any special predilection for a medium of high 

 tonicity. Its limit of toleration of salt in vitro is 

 closely similar to that of most pyogenetic organisms 

 about 5 per cent. In any case it has been shown by 

 investigators of salt packing that the outflow of serum 

 produced is so large that the salt is rapidly leached 



