288 MICROBES, FERMENTS, AND MOULDS. 
These words were written more than thirty years 
ago, and it. may be asked whether the immense pro- 
gress which science has made since that date has not 
somewhat modified the author’s opinions. Jousset 
de Bellesme is scarcely entitled to take these words 
and paraphrase them as follows:—“The microbe, 
where it really exists, is only a secondary phe- 
nomenon, and it would not be too much to say that 
no fresh element has intervened, either in small-pox, 
scarlatina, or tubercular disease; in such cases there 
is only an exaggeration and reproduction of normal 
elements, which, influenced by wholly obscure con- 
ditions, are evolved in an altogether unusual manner.” 
The definition given by Jousset de Bellesme is not 
that of contagious diseases, but of ‘those which are 
combined under the generic name of cancer. If he 
means to compare these diseases with cancer, such a 
comparison is impossible. It is well known that 
cancer is not contagious, and this fact alone places a 
gulf between these two kinds of disease. Cancer is 
not only not contagious nor is it conveyed by inocula- 
tion, but it is only hereditary in about a tithe of 
cases. Tuberculosis is, on the other hand, a con- 
tagious disease, because it is produced by microbes, 
and it may be set down as hereditary in nine cases 
out of ten. 
Jousset de Bellesme’s theory, therefore, explains 
nothing, and leaves the question absolutely untouched, 
since it throws no light on contagion and virulence, 
