

PREVENTIVE MEDICINE 249 



unable to check the course of the disease even by intravenous injec- 

 tions of serum undertaken 24 hours before the appearance of 

 symptoms. The serum confers a passive immunity which lasts at 

 most for 3 or 4 weeks. Injections should, therefore, be continued 

 at fortnightly to three-weekly intervals until the wound has com- 

 pletely healed. 



ANTHRAX. 



Anthrax (splenic apoplexy, splenic fever) is an acute affection 

 caused by a specific organism, the Bacillus anthracis. Its con- 

 tagious character has been known since 1836, and the etiological 

 significance of the bacilli was first demonstrated by Davaine in 

 1865. The organism is facultative. During the greater part of 

 the year in temperate countries no multiplication can occur owing to 

 the temperature being too low. However, even when the temper- 

 ature is favourable it is doubtful if it multiplies to any extent. All 

 the mammalia, including man, are susceptible. Of domesticated 

 animals cattle are the most frequent victims followed by pigs, 

 horses and sheep in the order given. It is a curious fact that sheep, 

 although highly susceptible to experimental inoculation, are in 

 nature somewhat infrequently infected with anthrax. Though it 

 is possible that the disease is more common among sheep than is 

 usually supposed, it is probably rare. The dog is more resistant, 

 but nevertheless (in Great Britain at any rate) has not a great 

 immunity against anthrax. It is difficult to infect poultry. While 

 young cattle are certainly as susceptible as adults, if not more so, 

 MTadyean has remarked in 39 outbreaks described by him that 

 most cases occur in adults. 



Anthrax is universal in its occurrence. Its distribution in 

 the United Kingdom is peculiar, some districts, though carrying a 

 large cattle population, being comparatively free from it while 

 other districts show a high mortality return. The following table, 

 compiled from the official returns, shows the number of cattle 

 attacked, the cattle population and the number attacked per hundred 

 thousand head for the four divisions of the United Kingdom, the 

 latter calculated on the average for the three years shown : 



