170 PHYSIOLOGY OF THE BACTERIA. 
been sick for two or three days and have pre- 
sented in their blood very slender and active rods. 
In the period of invasion the nasal mucus already 
contains small bacteriform elements. 
Diphtheria. — All the labors undertaken since 
Tigri, by Trendelenburg, (Ertel, Letzerich, Tom- 
masi, and Hueter, from a parasitic point of view, 
have attributed diphtheria to the presence of a 
Micrococcus. There is however a single exception, 
Eberth of Zurich, in a work published in 1872, 
regards a Bacterium as the agent of the diph- 
adeno contagion. 
According to new researches, which appeared in 
1873, the pus of pyeemia, or of purulent perito- 
nitis, inoculated, produces diphtheria because of the 
presence in it of bacteria. 
Laboulbéne had already pointed out the presence 
of Bacterium, accompanied by Vibrios and Mi- 
crococcus in pseudo-membranous affections. Some 
researches made in collaboration with Robin had 
given the same result, but these savants did not 
admit a relation of cause to effect between the 
micro-organisms observed and diphtheria. <Ac- 
cording to Duchamp, as shown by experiments 
cited in his inaugural thesis (1875), there are in 
false membranes Bacteria, Vibrios, and granu- 
lations. 
Taken alone, these micro-organisms appear to 
possess a very injurious action, but their mocula- 
tion does not produce diphtheria. The demonstra- 
tion of a causal relation between the Micrococcus 
