This is the title page of the *Treatise of Algebra* by Christian Wolff (1679-1754). Wolff was a student of Leibniz and is most famous for his work in philosophy. His school of philosophy, in fact, was the most prominent in Germany prior to Kant. This book was originally written in Latin in 1713. It first appeared in English in 1739, though this copy is of the second edition of 1765.

On pages 140-141 of his book, Wolff presents a derivation of the formula for the sums of the integers as well as the sums of the squares and cubes of the integers, a derivation which is generalizable to higher powers as well.

On pages 142-143, Wolff generalizes his earlier results and shows how to derive formulas for the sums of higher powers of the integers.

Here, on page 144, Wolff completes the derivation with the complete formula for the sums of third and fourth powers.

On pages 202-203, Wolff discusses some elements of the theory of equations. Note that he mentions Descartes' rule of signs, without attribution to Descartes. In fact, he attributes it to Thomas Harriot and claims further that no one had yet proven it. The first published proof of the result was due to Jean Paul de Gua de Malves (1713 - 1785), who gave two proofs in 1741 in a paper in the *Memoires *of the Paris Academy.

Index to Mathematical Treasures