CHANGES IN THE BLOOD. 107 



In such a case the greater part of the injected fluid is found 

 in the subcutaneous cellular tissue of the back in much the same 

 condition as before it was injected. It contains bacteria of the 

 most diverse forms, irregularly mixed together, and as numerous 

 as when examined before injection. No inflammation can be 

 observed in the neighbourhood of the place of injection. The 

 internal organs are also unaltered. If blood from the right 

 auricle be introduced into another mouse, no effect is produced. 

 Bacteria cannot be found in any of the internal organs, nor in 

 the blood of the heart. 



Koch therefore concludes that an infective disease has not 

 been produced as the result of the inoculation, but that the 

 death of the animal is due to a soluble poison — Sepsin — which 

 has been shown by the researches of Bergmann, Panum, and 

 others to exist in putrid blood. This supposition is confirmed 

 by the fact that when less fluid is injected the symptoms of 

 poisoning which follow are less marked, and are quite absent 

 when one or at most two drops have bieen injected. After the 

 use of such small quantities mice often remain quite well, but 

 a third of them, on an average, becoUie ill after the lapse of about 

 twenty-four hours. The less amount of putrid fluid injected, 

 the fewer mice become affected, but less than one drop is some- 

 times sufficient ; thus, of twelve inoculated with one-twentieth 

 to one-tenth of a drop each, only one was successfully infected. 



The first symptoms of the success of the inoculation with this 

 minute quantity is an increased secretion from the conjunctiva. 

 The eyes appear dull, and a whitish mucus collects between 

 the lids, and finally glues them together. At the same time 

 lassitude sets in, the animal moves little and languidly; as a 

 rule it sits quite still, with its back much bent and its extre- 

 mities closely drawn up. It then ceases to eat ; its respirations 

 become slower ; weakness gradually increases, and death comes 

 on almost imperceptibly. Convulsions never precede it (they 

 always do so in anthrax). After death the animal still remains 

 in the sitting posture with its back strongly bent; whilst a 

 mouse which dies from anthrax is always lying on its back or 

 side, with its stiffened limbs fully extended. Thus, by the 

 position of the body after death, a fatal result produced by the 

 inoculation of putrefying blood is at once distinguished from 

 that occasioned by inoculation with the material of anthrax. 



