I agree with opallady. That puzzle cost me a lot of time until I finally remembered the time period in which Addison lived. Then the word "physick" made more sense as the general term for what passed as a medicine or a remedy in that day. Addison and Newton were contemporaries, but it is not likely that the science that came to be known as physics was wide-spread common knowledge at that time; especially Addison's circle of poets, playwrights, and politicians.
"Great spirits have always encountered violent opposition from mediocre minds." ~ Albert Einstein