He had mastered both integral and differential calculus by the age of 15.

他在15岁时就已了微积分。

He improved chemistry by improving its language, just as Newton, a century before, had improved physics by systematizing and ordering its language-in the process, as you may recall, developing the differential and integral calculus.

他通过改进化学语来改进化学，就像一个世纪前通过系统化和整理其语来改进物理学一样——您可能还记得，在这个过程中，发展了微积分和积分。