74 DE. BASTIAN ON THE 



Cohu's journal in an important paper by Dr. Koch entitled " Die 

 Aetiologie der Miltzbrandkrankheit." The organism met with 

 in this disease is also a Bacillus, indistinguishable by the micro- 

 scope from that found in hay -infusions. When exposed to air at 

 a temperature of about 37° C. it also grows into filaments, which 

 speedily develop therein the highly refractive spore-like bodies, 

 and then become disintegrated. Koch found, moreover, that the 

 Bacilli themselves of splenic fever could only resist a compara- 

 tively short amount of desiccation, though he concluded from 

 his experiments that the spores could retain their vitality and 

 power of communicating the disease for years when imbedded in 

 the midst of certain dried matter. No sufficient details, how- 

 ever, are given in regard to this latter point ; and it cannot be 

 considered that Koch's evidence proves that Bacilli spores can 

 resist prolonged periods of desiccation, (1) because he found that 

 the splenic-fever matter, containing germs, was only potent when 

 pieces of spleen or blood in mass were dried, in the midst of wJiich 

 the germs may not have heen really desiccated at all; and (2) because 

 it has not yet been distinctly proved that it is the actual spores, 

 or only the spores and not certain chemical principles in the me- 

 dium, constituting soluble or ' particulate ' ferments, which com- 

 municate the disease. Any such chemical principles might preserve 

 their integrity in the midst of the colloid masses above mentioned 

 just as well as spores. 



This latter consideration is especially strengthened by recent 

 accessions to our knowledge. Thus we learn from Dr. Koch him- 

 self that though the hay-Bacillus is so similar to the Bacillus of 

 splenic fever as to be microscopically indistinguishable therefrom, 

 yet that the former organisms are quite powerless to excite splenic 

 fever when inserted beneath the skin of rabbits. And although 

 it may be said that morphological similarity does not necessarily 

 imply identity in the physiological or molecular actions of the 

 two organisms, yet it may fairly be insisted that, as regards these 

 two organisms in particular, there is evidence that in all outward 

 respects their course of life and properties are also similar. But even 

 greater need for caution in the same direction might be brought 

 home to us by the now admitted fact that the common septic 

 ferment excretes or helps to form a chemical principle *, existing, 

 according to Prof. Burden Sanderson, in the form of minute 



* Just as other allied organisms give rise to grains of blue or other pigment 

 in the jelly which envelops them. 



