Maryland Archaeological Conservation Laboratory

Curator's Choice 2017

Under the Microscope: A Nineteenth-Century Flea Glass

February 2017
By Patricia Samford, MAC Lab Director

Handled flea glass dating to the second quarter of the nineteenth century."The eye of a human being is a microscope, which makes the world seem bigger than it really is."  Khalil Gibran (1883-1931) 

Nineteenth-century physicians often found that they needed more than just the naked eye to assist them with offering quality health care to their patients.  Using magnifying devices, like this rudimentary microscope known as a flea glass (Figure 1), allowed them to gain a better view of wounds or for routine examinations of ears, eyes and throats.

Invented in the 1500s, flea glasses were used primarily for studying insects and other small life forms (hence the name), rather than for medical purposes. A small, convex lens held nearest to the eye and a larger, flat lens at the opposite end of a short metal tube allowed for magnification ranges of 6x to 10x. 

Figure 2.  Flea glass or simple microscope from the Federal Reserve site.  Top and side views. Photo by Nichole  Doub, Maryland Archaeological Conservation Lab.The lenses and iron fittings of a flea glass or similar simple microscope were recovered from a circa 1850 to 1870 privy excavated at the Federal Reserve site (18BC27) in Baltimore (Figure 2).  This Figure 3.   Simple microscope mounted on a stand.  Similar instruments were illustrated as early as 1685 in Oculus Artificialis by Johann Zahn.magnifying instrument may have been mounted on a stand, similar to the instrument shown in Figure 3 (Bradbury 1968). A medical use for this scientific instrument was assumed because the privy fill also contained a number of other artifacts relating to medical care—a mortar and pestle, a salve jar, a pill tile, a leech jar, a number of medicine bottles and a possible stethoscope. 

Documentary records indicate that the privy was located near the Southern Dispensary, a branch of the Baltimore General Dispensary.  A dispensary supplied free medicine and health care for citizens who could not otherwise afford medical services. The Southern Dispensary, funded by charitable donations and a small appropriation from the city, was incorporated in 1847 and remained in operation until at least 1889 (Woods 1847; Register 1890).  The dispensary offered both clinic and in-home health care (Polk 1888). 

With large populations living in close proximity, it was critical for cities to provide medical services. At various times during the eighteenth and nineteenth centuries, infectious diseases, including tuberculosis, cholera, yellow fever and smallpox, struck Baltimore (Mdmedicine 2017).  Clinics, like the Southern Dispensary, played key roles in treating infected individuals and preventing widespread epidemics.

Bradbury, S.
1968 The Microscope Past and Present. Pergamon International Popular Science Series. Pergamon Press, Ltd., Oxford.
2017 Epidemics in Maryland. Website accessed January 13, 2017.
Polk, R. L.
1888 The Medical Directory and Register for Baltimore, Washington, Maryland and District of Columbia . R. L. Polk & Co., Baltimore.
1890 Annual Reports of the Register of the City and the Commissioners of Finance. John Cox, Printer, Baltimore.
Woods, John W.
1847 The Act of Incorporation and By-laws, of the Southern Dispensary of Baltimore: Together with a List of Officers for 1847. Baltimore
Zahn, Johann
1685 Oculus Artificialis Teledioptricus Sive Telescopium. W�rzburg, Germany.

Human Trafficking GET HELP

National Human Trafficking Hotline - 24/7 Confidential

1-888-373-7888 233733 More Information on human trafficking in Maryland

Customer Service Promise

The State of Maryland pledges to provide constituents, businesses, customers, and stakeholders with friendly and courteous, timely and responsive, accurate and consistent, accessible and convenient, and truthful and transparent services.

Take Our Survey

Help Stop Fraud in State Government

The Maryland General Assembly’s Office of Legislative Audits operates a toll-free fraud hotline to receive allegations of fraud and/or abuse of State government resources. Information reported to the hotline in the past has helped to eliminate certain fraudulent activities and protect State resources.

More Information