Category Archives: 1920s

Dethloff’s Spirograph, 1926

From “Methods in pulmonary physiology”, by Bertels H, Bucherl E, Hertz CW, Rodewald G, Schwab M.  Translated by Workman JM. Hafner Publishing Co., 1963, page 24.

“In Dethloff’s apparatus, the difference in volume of expiratory gases before and after absorption of CO2 is used to measure CO2 output.  To this end two gas meters are placed in the circuit, one proximal and one distal to the CO2 absorber.  The difference in reading between the two gas meters provides a continuous measure of CO2 output.”

Spirometer, Long Life, Spirometer Company of California, 1921

From “Youth obtaind and retaind” by George Starr White, Phillips Printing Company, 1921, Page 34.  The spirometer was developed by Charles E. Ramage

“This littl instrument is “a western product” devized by a westerner seeking for helth, which he found, and is manufactured by the Spiro-Meter Co. (Inc.) of Pomona, California.  These peopl ar wel named “helth promoters.”  Probably their littl “lung watcher” is doing more to interest peopl in the development of their breathing than any other instrument.  This littl instrument is only the size of a watch and can be carrid like a watch attacht to a chain or cord like a watch. One can set the hand bu the stem setter, and many times a day watch just how much air he can expel from his lungs. Then as I hav said before, the reflex causes a greater amount of air to be drawn back into the lungs.”

{FYI, the misspellings appear to be deliberate as this is how the author spelled words throughout the book.}