Whitney was a pioneer in the field of the medical museum and originator of the method of quick diagnosis.

Later, he was much sought after by the courts for his exceptional anatomical knowledge, especially in determining if poison had any bearing on a case.

[citation needed] After receiving his M.D., Whitney spent three years studying anatomy abroad in Berlin,[3] Munich,[3] and Strasburg.

"During his tenure, Whitney saw the movement of diagnostic pathology from the realm of the surgeon to the hand of the specialist pathologist.

His rapid histological method for immediate pathological diagnosis was applied in the operating room, at the bedside, and at court.

[6] In 1879 Whitney was appointed curator of the Warren Anatomical Museum at the Harvard Medical School,[2] a capacity he filled for 42 years until his death.

[3][6] Under his curatorship, the Warren Museum passed from its original home in the old Harvard School building on North Grove Street in Boston to more adequate quarters on Boylston Street, and then to its present location in the front block of the Longwood Avenue building.

[3] Later he was part of a committee representing the principle departments of instructions and research work at the Medical School.

[3] He also served on the 1880 committee that supervised the planning and building of the old Harvard Medical School on Boylston Street, and again on the 1900 committee that considered the plans for a new group of buildings for the Medical School on Longwood Avenue.