The Manometric Blood Gas Apparatus was a revision on the original, fairly simple volumetric glass apparatus designed by Dr. Van Slyke in around 1917. The instrument liberated and isolated "the desired gas contained in a known volume of solution, and recording in millimeters of mercury the pressure of that gas at a known fixed volume" allowing for a more accurate test and the ability to measure very small concentrations of gases. The instrument was key in the analysis of blood gas (blood oxygen concentration) and was used extensively in the treatment of diabetes, pneumonia, tuberculosis, and other blood related ailments.

Black and white plastic instrument; main body is white and stands vertically; an aluminum pole is attached to each side parallel to the main body, the poles are attached to the main body in two places; the front of the main body has a control panel and two dials in the center and clips for holding glassware on each side; the clips on the left side are combined with a rigid plastic support piece that extends parallel to the main body and is attached to the inside of the object; the black base is carved out in the front to accept and hold the glassware.