HISTORICAL. 275 



malaise, bronchial irritation, a sense of oppression across 

 the chest, etc, and a rapidly fatal termination, with very 

 aggravated symptoms centred in the thorax, usually follows. 

 Thirdly, an infection may probably take place through the 

 intestinal tract, which is now the first part to give rise to 

 symptoms. In all these forms of the affection in the human 

 subject, the bacilli are in their distribution much more 

 restricted to the local lesions than is the case in the ox, 

 their growth and spread being attended by inflammatory 

 oedema and often by haemorrhages. 



Historical Summary. Historical researches leave little 

 doubt that from the earliest times anthrax has occurred 

 among cattle. For a long time its pathology was not under- 

 stood, and it went by many names. During the early part 

 of the present century much attention was paid to it, and, 

 with a view to finding out its nature and means of spread, 

 various conditions attaching to its occurrence, such as those 

 of soil and weather, were exhaustively studied. Pollender 

 in 1849 pointed out that the blood of anthrax animals con- 

 tained numerous rod-shaped bodies which he conjectured 

 had some causal connection with the disease. In 1863 

 Davaine announced that they were bacteria, and originated 

 for them the name bacillus ant hr ads. He stated that 

 unless blood used in inoculation experiments on animals 

 contained them, death did not ensue. Though this con- 

 clusion was disputed, still by the work of Davaine and 

 others the causal relationship of the bacilli to the disease 

 had been nearly established when the work of Koch 

 appeared in 1876. This constituted that observer's first 

 contribution to bacteriology, and did much to clear up the 

 whole subject. Koch confirmed Davaine's view that the 

 bodies were bacteria. He observed in the blood of anthrax 

 animals the appearance of division, and from this deduced 

 that multiplication took place in the tissues. He observed 

 them under the microscope dividing outside the body, and 

 noticed spore formation taking place. He also isolated 

 the bacilli in pure culture outside the body, and by inocu- 

 lating animals with them, produced the disease artificially. 



