Issues to 1887 are available as pdfs and can be searched for words in the title and abstract, as well as author name, but not the full text.
It's amazing how the attentions of the scientific community have changed. The BBC article features items from the first few years, including "a woman who swallowed a bullet, which was expelled from her body in a very surprising way."
Another early item highlighted is on "a grisly boating accident during a thunder storm in Oxford", one of 57 items in this collection found searching on the keyword lightning describing the impacts, including on humans, and methods of protecting buildings.
Later issues of Phil Trans, after it was separated into two parts, are also online.
All these articles were written by people, who may be some people's ancestors - perhaps yours. Maybe you'll find something interesting on a topic or place in your family history.
Links are from http://rstl.royalsocietypublishing.org/