$20.00 – $85.00
Blood Pressure Manometer
2 patents – construction improvement for less breakage and better accuracy, second has a mercury reservoir and glass measuring tube.
First USA patent on the stethoscope – for a concealed noiseless spring that eliminated vibrations.
2 patents – 1 for the design of chair, 1 for the cup holder for spittoon.
Mortar and Pestle
Felix Hoffman's patent on his refinement of the formulation that Charles Frederic Gerhardt tried but gave up on.
Bausch and Lomb Microscope
First Bausch & Lomb microscope. Both witnessed the patent document. Print includes these signatures.
Phoropter (for eye testing)
Invented by Henry DeZeng, who also trademarked the word Phoropter – a word that is now used for visual testers.
Ophthalmoscope (for examining eyes)
2 patents – 1 one for a new and improved version, 1 for a battery dry handle.