Small Victories

In my previous post discussing "The elements of the new calculus for differences and sums," I suggested that Leibniz's equation for the tangent to a rectangular hyperbola should have been t = -x, rather than t = -y, as Child (p. 138) has it. This evening I picked up the book (C. I. Gerhardt, Die Entdeckung der höheren Analysis, 1855) in which the original Latin text appears as an appendix. And lo and behold there it was: "ergo t aequ. -x."