Notes on Nursing: What it is and What it is Not is the first of its kind. It is a text in which a nurse defines the nursing role and theory of practice to promote patient well-being. Nightingale's environmental theory, which still persists in nursing education today, calls for "utilizing the environment of the patient to assist him in his recovery." This includes cleanliness and sanitation of the hospital as well as public health measures to promote access to an unpolluted environment.

Nightingale sees district nursing, or "home healthcare" as it is called in the U.S., as a mechanism for caring for local low-income individuals experiencing illness. With help from William Rathbone, Nightingale begins a training school for nurses interested in district nursing.