The title page of Leonard Euler’s *Integral Calculus*, vol. 1 (1768). The complete work in three volumes appeared in the interval 1768 – 1770. This was the first complete textbook published on the integral calculus. The entire *Integral Calculus* is available at the Euler Archive.

Euler’s discussion on page 121 of volume 1 of his *Integral Calculus* concerning the integration of logarithmic and exponential functions. Note that Euler used *lx* to represent what we write as ln(*x*)*.*

An excerpt, pp. 182–183, from volume 2 of Euler’s *Integral Calculus*, demonstrating a series solution for a differential equation.