INFECTION. 105 



The discovery of tliese two observers gradually drew the at- 

 tention of scientists to the study of this disease, and it may be truly 

 asserted that no single disease has enjoyed so much observation in 

 modem or ancient days. 



By means of a succession of experiments Brauell came to the 

 knowledge that the peculiar staff-like bodies appeared from one, two, 

 or three, and in some cases eight to ten hours before the death of the 

 diseased organism, and when the course of the disease was very acute, 

 but a few moments before its fatal termination, while they were not 

 to be seen in the blood of convalesents, lie credited these objects 

 with a ])rognostic and diagnostic value, but denied to them any etio- 

 logical importance, as the disease could be produced with blood which 

 did not contain them, a fact which will find its explanation later on. 



These peculiar bodies were not looked upon in the same light 

 by different observers, some considering them as coagaluted fibrin 

 (Briickmiiller, "Zootomie- Pathologique"), fragments of broken- 

 down tissues, blood-crystals, while Delafond looked upon them as 

 a species of leptothrix. In 1S60 the last-named author adopted the 

 views of Brauell. 



In 1803 Davaine declared these bodies to be bacteria, and, in 

 order to distinguish them from the motory bacteria of putrefaction, 

 gave them the name of hacterklicn. As the blood without them 

 was not infectious, he declared them to be the specific cause of this 

 disease. The bacteridii\} are destroyed by putrefaction, but may be 

 preserved for a long time in a desiccated condition. 



After this time, there followed a period of the greatest diver- 

 gence in the views of different observers as to the true nature and 

 place of these objects : all sorts of things — blood-crystals, the bac- 

 teria of putrefaction, the cent-like rolls of the blood-cells, etc. — 

 were declared to be the same as the bacteridiiB. Davaine's work, 

 more than that of any other author, gradually led to the production 

 of order out of this chaos. 



He found the bacteria to be present in the majority of cases of 

 anthrax, an<l that they frequently appeared before the outbreak of 

 the symptoms of diseases ; when they disappeared, by putrefaction 

 or otherwise, the infectiousness of the blood ceased. The number 

 of bacilli in a single drop of blood was estimated by Davaine at 

 eight to ten millions ; and he claimed that a drop of blooil diluted 

 to a million times its volume by water was still competent to pro- 

 duce infection. 



The modern workers in this field of mycology are sufficiently 

 known through our general study of the bacteria. 



