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Mr. G. F. Dowdeswell. Action of Heat [June 15, 



No. 3, diluted and prepared as above mentioned, but unheated, while 

 guinea-pig No. 5 received in similar manner - 3 cub. centim. of the 

 same fluid superheated and cooled. The following day, twenty-five 

 hours after injection, No. 4 was prostrate, in a state of collapse, and 

 the next morning was found dead with the same symptoms and micro- 

 organisms as in previous cases, while No. 5 was quite unaffected, 

 feeding heartily and with temperature unaltered. This animal 

 remained healthy and unaffected for some days, and subsequently 

 died from an accidental cause. On examination no symptoms what- 

 ever were found, either of septicheemia or peritonitis; there was no 

 exudation of any sort and the blood was free from organisms. The 

 following day the exudation fluid of No. 4 was diluted and rendered 

 alkaline in the same manner as in the previous experiments, enclosed 

 in tubes and superheated as before; of this l'O cub. centim. was 

 injected into the subcutaneous tissue of guinea-pig No. 6, which, not- 

 withstanding the large quantity it received, remained totally un- 

 affected and was ultimately killed. 



Some cultivation experiments were then made in different nutrient 

 Huids, both with the sterilised and the unsterilised exudation serum, 

 the result was that in all cases excepting one, in which there was 

 reason to believe that the result was due to accidental contamination, 

 no development of organisms occurred with the sterilised fluid, which 

 it invariably did with the unsterilised. 



In the septichsemia of Pasteur, the characteristic organism is a 

 Bacillus, somewhat similar morphologically to the B. antliracis, and 

 one of the forms of the hay Bacillus, B. siibtilis of Cohn, the ubiquitous 

 organism which developes so readily and constantly in most organic 

 infusions, from atmospheric or other contamination, and until the 

 specific morphological characters of these organisms are better 

 discriminated than they are at present, that is probably until there is 

 a further substantial advance in our optical appliances, it is scarcely 

 safe to draw any conclusion from their occurrence in cultivations, 

 unless these are numerous and repeated, with rigorous control 

 experiments. 



In this case, i.e., Pasteur's septichaemia, or the malignant oedema 

 of Koch, in the guinea-pig, I have invariably found both in this, as in 

 other series of experiments, that in animals examined immediately 

 upon death there are none of the specific organisms (the Bacillus 

 described, — which is so large that it can scarcely be overlooked) to be 

 found in the blood, or in any of the organs of the infected animal, 

 and that the blood is not infective. After death, however, they 

 speedily invade the organs of the animal, the kidneys and the spleen 

 being apparently the first attacked; hence the necessity in all these 

 cases of examining the subject immediately after death. 



