Early trichinoscopes were manufactured by two German companies, H. Haupner and Paul Waechter. They were introduced in the third quarter of the 19th century and produced well into the 20th century. The one pictured above was made in 1920 and saw use in New Jersey. The scope is designed to be carried in the field by the inspector.
The trichinoscope is a specialized microscope for finding Trichinella in pork. Sanitarians and meat inspectors would verify that only worm-free pork was used in lightly cooked sausage. More recently, the trichinoscope is used to ensure the safety of wild-game meat, specifically that which is served at game dinners.
A thin slice of raw meat is compressed between two glass plates known as compressoria. The specimen is examined at 40x and 100x for the nematode Trichinella spiralis. Dyes were not needed to see the cyst in larger versions of the field instrument.
A more recent version of a trichinoscope kit is pictured to the left in its original wrapping. The compact kit contains everything necessary to conduct the examination of the raw meat, including a hand-held, low power scope and a dye container. These kits were manufactured post-war by PZO in Warszawa, Poland, and issued to meat inspectors and veterinarians.