GREAT EPIDEMICS—ASIATIC CHOLERA. 299 
treat, if there be occasion, such forerunners of the pesti- 
lence. 
We find that there is as yet no specific against cholera. 
Can therapeutics indulge the hope of hereafter discovering 
one? We have no reason to doubt it. An heroic remedy 
for intermittent fevers has been discovered, quinine, though 
we have no knowledge whatever of the first cause of that 
disease, nor the least notion of what the miasma of marshes 
is. Perhaps in the same way we shall learn how to destroy 
the miasma of cholera before penetrating its inner nature. 
Meanwhile, it is allowable to rely on this, that the cholera, 
subject in that respect to that mysterious law which goy- 
erns the secular evolution of epidemics, will lose its inten- 
sity in proportion to its remoteness from its origin. Those 
morbid germs, those forms of virus, seem not to be gifted 
with the power of indefinite reproduction. They exhaust 
themselves by their own activity. The death they sow at 
last overtakes themselves some day. Is it the influence of 
civilization which thus sets a limit to their deadly work, or 
is that end assigned to their career the fulfillment of a 
fixed decree? In any case the cholera must die some day. 
Till then the best way of working for its annihilation is to 
pursue the study of it scientifically. 
We must see, therefore, what science and its teachings 
suggest for the future in the nature of labors that may 
serve to elucidate the serious problem of the character of 
cholera, and of infectious diseases generally. Researches 
in physics and chemistry grow daily easier, so simple are 
their phenomena, so sure their formulas, their theories so 
interdependent, and their processes so exact. The share 
given in them to discovery and origination becomes ever 
smaller; that taken by measurement and calculation grows 
constantly in proportion. The masters have enounced the 
grand laws and fundamental methods; the scholars do lit- 
tle else than determine special cases. This is less true of 
