192 



IXFECTIVE DISEASES. 



Within the Inst few ye:ii's a great change of opinicjn has taken 

 place. Bacterioldgists have in\e.stiga,te(l the Avhole .subject, sii that 

 at the present day "we knew" exactly tlie cause iif anthi'ax. 



Bacillus anthracis (Ilacteridle du diarhon, Bacillus of splenic 

 ferei\ W'ool-sortfrs Ji.sen-^e, <ir malignanl pustule). — Rods 5 to 20 /i 

 long and 1 to 1 '25 /x broad, and tin-eails ; spoi-e-fornia.tioii p)i'esent. 

 As a thoi'ougli knowledge of the life-history of thi.s bacillus is of the 

 gveat(.'st importance, the various steps to be followed in a pi-actical 

 study of it will lie successively treated in detail. Its morphological 



I'lti. il2. — B.vciLLrs AxTHRACIs, :■, 12U0. Bluud coriJUscle.s and IjacilU 

 unstained ; from an inocailated muuwe (Fkaxkei. and Pb'EIFFEu). 



and biological characteiistics have l>een vei'}' completel}' worked out, 

 and it sei'ves as an excellent subject foi- gaining an acquaintance 

 ^\ith most cif the methods employed in studying micro-organisms. 



A mouse inoculated with the bacillus or its spjoi'es will die in 

 fi'oni t\\'euty-foiu' to forty-eight houi's, oi- more i-arely in from 

 forty-eight to about sixty hours. 



Exaiiiiruition i(fter ]>eat]i. — The spleen is found to be considerably 

 enlarged, ami mav be remo\ed, and examined by making cover-glass 

 preparations, inoculations in nutrient media, and subsequently 

 sections. 



Corer-ijlass Preparations. — In cover-gl.a.ss preparations of the 

 blood of the spleen the bacilli are found in en(n-mous numbers. 

 Prepai-ations should also be made with blood from the heart and 

 with the exudation from the lungs and other organs ; it will be 



