Microscopes for Health and Medicine

c. 1850 – c. 1950

Richard Paselk, Curator

"Trichinosis" microscope

Designed in Germany in the late 19th century, the "Trichinosis Microscope" was sold as aid for the control of trichinosis, a muscle wasting disease caused by worms encysted in muscle, and common in pork. Its rugged design, simplicity and quality also made it a good microscope for home or student for making low and medium power observations. The specimen on display was purchased at a garage sale in Eureka, California in 1982, but the seller claimed no knowledge of its prior history. Was it used for local public health purposes to monitor pork? Was it brought by a German immigrant? Or perhaps it was bought by a student or a collector? The stories of many instruments will remain mysteries.

Microscopes are used to provide a magnified view of small objects or small portions of objects. In effect they bring objects very close to the observers eye and thus fill the field of view with the object. The magnification of this particular instrument is varied by changing the button lens objectives—the lowest powers are obtained by using the single “1” objective, while a combination of the three lens gives the highest power (see image below). The fine focus is accomplished by a tilting stage mechanism. One of many experiments in fine focusing during the nineteenth century, the tilting stage has the advantage of low cost, but the disadvantage that over most of its range the specimen will be tilted and thus not all in focus at the same time.

Description

Standing 10 1/2” tall with the bottom of the rack flush with the limb. The base, stage and limb are a single piece of “bronzed” cast iron (green with gold highlights), while the focusing rack and fittings are bright brass, and the tube and draw-tube are nickel plated brass. The stage has a vulcanite top plate which is attached to the base assembly by a hinge on one side, the other side being spring loaded with a single screw to give a tilting fine focus. A six hole disk diaphragm is below the stage and there is a plane and concave double faced mirror in a brass cell mounted on a swinging arm. The hinge and edge of the diaphragm can be seen in this view of the microscope. The three piece button objective is stamped 1,2 &3 on the individual segments, as seen in the image below. The society eyepiece is stamped with a 2. The microscope and individual lenses are shown in the photograph below.Various parts of the microscope have a ‘7’ stamped on them.

© R. Paselk 2013, Last modified 31 December 2020