  In spite of its title, the book mostly treats probability theory: the law of
large numbers (regarded as a principle); formal definition of a random variable
and law of distribution; the misnamed Cauchy distribution; functions now named
after Dirac; difference between objective and subjective probabilities;
approximation of the Bernoulli theorem for rare events (but not yet the Poisson
distribution); investigation of the significance of empirical discrepancies.
Following Laplace, he actually attributed probability to applied mathematics.
  Poisson calculated the optimal number of jurors and of their majority for
conviction/exoneration of the accused and in general studied the conditions
enabling to minimize miscarriage of justice. He replaced guilty and innocent by
convictable or not.
