He suffered from an acute throat infection in the mid-1880s and had a brain tumor, which led to a stroke and paralysis.

Smoking and frequent exposure to toxic photography chemicals likely contributed to the development of his tumor.

He also took extensive photographs of areas in New York State, including on Long Island and along the Hudson River.

Through his inventions he was able to photograph the human vocal organs, thus contributing to the perfection of this type of medical photography.

Independently wealthy and the Deputy Water Purveyor for the City of Brooklyn, Brainerd was an advanced amateur photographer adept at exploring new techniques.