800 FRAGMENTS OF SCIENCE 



Now the very first step toward the extirpation of these 

 contagia is the knowledge of their nature; and the knowl- 

 edge brought to ns by Dr. Koch will render as certain the 

 stamping out of splenic fever as the stoppage of the plague 

 of pShrine by the researches of Pasteur.* One small item 

 of statistics will show what this implies. In the single 

 district of Novgorod in Kussia, between the years 1867 

 and 1870, over fifty-six thousand cases of death by splenic 

 fever, among horses, cows, and sheep were recorded. Nor 

 did its ravages confine themselves to the animal world, for 

 during the time and in the district referred to, five hun- 

 dred and twenty-eight human beings perished in the ago- 

 nies of the same disease. 



A description of the fever will help you to come to a 

 right decision on the point which I wish to submit to 

 your consideration. "An animal," says Dr. Burdon San- 

 derson, "which perhaps for the previous day has declined 

 food and sho\m §igns of general disturbance, begins to 

 shudder and to have twitches of the muscles of the back, 

 and soon after becomes weak and listless. In the mean- 

 time the respiration becomes frequent and often difficult, 

 and the temperature rises three or four degrees above the 

 normal; but soon convulsions, affecting chiefly the muscles 

 of the back and loins, usher in the final collapse of which 



their blood Bacillus anfhracis ceases to act as a ferment. Pasteur announced 

 more than six years ago the propagation of the vibrios of the silkworm disease 

 called flacherie, both by fission and by spores. He also made some remarkable 

 experiments on the permanence of the contagium in the form of spores. See 

 "iStudes sur la Maladie des Vers a Sole," pp. 168 and 256. 



^ Surmising that the immunity enjoyed by birds might arise from the heat 

 of their blood, which destroyed the bacillus, Pasteur lowered their temperature 

 artificially, inoculated them, and killed them. He also raised the temperature 

 of guinea-pigs after inoculation, and saved them. It is needless to dwell for a 

 moment on the importance of this experiment. 



