Humanity has but three great enemies: Fever, famine and war; of these by far the greatest, by far the most terrible, is fever. Gad, the seer of David, estimated aright the relative intensity of these afflictions when he made three days' pestilence the equivalent of three months' flight before the enemy, and of three (seven) years of famine. As far back as history will carry us, in ancient Greece, in ancient Rome, throughout the middle ages, down to our own day, the noisome pestilence, in whatsoever form it assumed, has been dreaded justly as the greatest of evils.
It is worthy of comment that three of the greatest benefits conferred on mankind—beside which it would be hard to name three of equal importance—have been in connection with the fevers: The introduction of cinchona, the discovery of vaccination and the announcement of the principle of asepsis. Too great a boon for