He was also (as was pointed out in section 10-5) one of the early student of mathematical probability; his book in this field, the Ars conjeclandi, was posthumously published in 1713. There are several things in mathematics which now bear Jakob Bernoulli’s name; among these are the Bernoulli distribution and Bernoulli theorem of statistics and probability theory, the Bernoulli equation, the Bernoulli numbers and Bernoulli polynomials of number-theory interest, and the lemniscate of Bernoulli encountered in any first course in the calculus. In Jakob Bernoulli’s solution to the problem of the isochrones curve, which was published in the Acta eruditorum in 1690, we meet for the first time the word integral in a calculus sense. Leibniz had called the integral calculus calculus summatorius; in 1696 Leibniz and Johann Bernoulli agreed to call it calculus integralis. Jakob Bernoulli was struck by the way the equiangular spiral reproduces itself under a variety of transformations and asked, in imitation of Archimedes, that such a spiral be engraved on his tombstone, along with the inscription ‘’Eadem mutate resurgo’’ (‘’I shall arise the same, though changed’’)