Mead proves that the plague is contagious from Thucydides,
Lacretius, Aristotle, Galen, and common experience (p. 10 - 20)
; and he refutes (Preface, p. 2 - 13) the contrary opinion of
the French physicians who visited Marseilles in the year 1720.
Yet these were the recent and enlightened spectators of a plague
which, in a few months, swept away 50,000 inhabitants (sur le
Peste de Marseille, Paris, 1786) of a city that, in the present
hour of prosperity and trade contains no more then 90,000 souls
(Necker, sur les Finances, tom. i. p. 231.).