90 REVIEW. 



•withoufc the fibres enlarging, and lost their infective powers. 

 That this death was due to the absence of oxygen was shown by 

 placing a drop of blood infected by the Bacilli under the micro- 

 scope ; examined by the microspectroscope, it gave the hands of 

 oxyhfemoglobin ; the fibres in this drop increased four or five 

 times in length in three hours ; but then the oxygen was clearly 

 nsed up, as the presence of the absorption-band of reduced 

 hseinoglobin showed. From this moment the growth of the 

 basillar fibres ceased, although true putrefaction had not set in. 

 One of the first signs of death is the opalescence of the fluid and 

 the falling to pieces of the fibres, as is well illustrated in Bol- 

 linger's article in Ziemssen's ' Handbiich der Spec. Pathol, und 

 Tberap.,' p. 465. In connection with the discussion which is 

 going on as to the " plasticity^' of the Bacteria, I should add 

 that Koch says that he has never observed any passing of the 

 fibres into micrococci, or the hke; but why they should do this 

 when dying I can hardly see, and wonder that any one can 

 expect it, especially as we know — thanks to Koch — the mor- 

 phology of the alternation of generation in this species of the 

 ScMzophyta ; and, further, I imagine that no one who has 

 any clear ideas as to what forms are would imagine that a 

 species, a form, or what you please to call it, will or can, 

 under our eyes, pass into a form of totally diff'erent physio- 

 logical and, unfortunately, we must add, pathological, capabili- 

 ties. If, however, air be allowed to enter the results are alto- 

 gether different ; the fiibres increase greatly in length, and often 

 spores appear after forty-eight hours. The spores and fibres 

 soon sink to the bottom of the glass; a watchglass was used. 

 The other Bacteria, which the air had brought in, disappear, the 

 eharacteristic smell appears, and the supernatant fluid becomes 

 quite clear. Dilution of the fluid with a moderate amount of 

 distilled or of spring water makes no evident difference, but a 

 large quantity {e. g. twenty times as much) kills the Bacilli. 

 Dampness, then, such as that to which either a body killed by 

 splenic fever is exposed when buried to some depth, or left in 

 fields, stables, or skinning yards, or the excreta of some sick 

 animal are exposed, does no harm to the Bacilli, while it hinders 

 the evaporation of the nutritious fluids in which the Bacillus has 

 done its harmful work. Further, it is certain, from repeated ex- 

 periments, that mice injected with a fluid rich in Bacilli avthracis 

 die after twenty-four hours, while a fluid which contains but few 

 spores is quite as successful in tliree or four days. Let only 

 spores be formed, and specimens of dried Bacilli will be as fatal 

 four years after, as ever they were; but the fibres will not 

 retain their activity for more than five weeks. To these facts, 

 thus rapidly recapitulated, let it be added that neither Koch nor 



