John Jacob Abel the position of chair of the department until he retired at the age of 75 in 1932. Ever since his early years in Europe, Abel showed great interest in isolating pure form of internal gland hormones. The first work that led to his international reputation as a pharmacologist and biochemist was the isolation of epinephrine from adrenal medulla. However, he was only able to isolate a monobenzoyl derivative of epinephrine. While he was improving his processes on decomposing the benzoyl derivative to obtain salts of epinephrine using saponification, a Japanese chemist J. Takamine, who had visited his lab, was able
Jacob Bernoulli exactly the same time, no matter what the starting point. It had been studied by Huygens in 1687 and Leibniz in 1689. After finding the differential equation, Bernoulli then solved it by what we now call separation of variables. Jacob Bernoulli's paper of 1690 is important for the history of calculus, since the term integral appears for the first time with its integration meaning. In 1696 Bernoulli solved the equation, now called the Bernoulli differential equation, Jacob Bernoulli also discovered a general method to determine evolutes of a curve as the envelope of its circles of curvature. He also investigated