From, The Year Book of General Medicine, Volume 1, Year Book Publishers, 1908, page 90.

“A simple aseptic mouthpiece for the spirometer is described by Thomas A. Storrey.  This mouthpiece (A) is made of wood, beveled on one end to fit easily between the lips.  The other end is made to fit snugly in the bore of the rubber tubing (B) which leads to the spirometer.  These may be made anywhere.  The Narragansett Machine Company of Providence, R.I., has furnished me with tips at the rate of $3 per thousand. Each mouthpiece is used but once. It is then thrown away. At one-third of a cent each this is not extravagant.  With such tips in use the danger of spreading contagion from mouth-to-mouth in our anthropometric investigations would disappear.  (Fig. 9)”