Existing comment:
Zeiss microscope:
Maj. Walter Reed and Typhoid Board member, Lt. James Carroll, used this microscope. Between 1898 and 1899, Dr. Carroll used a microscope to diagnose patients with typhoid, concluding that Army doctors identified only half of the cases correctly. By collecting detailed case histories of soldiers from over 100 regiments, the board disproved several theories of how typhoid was transmitted and established that an infected person directly or indirectly spread the disease to others in his unit. |