226 NATURE STUDY REVIEW [8 :6— Sept., 1912 



1. Some Studies of Breathing. 

 (A) The Nature Study Approach. 



1. Apparatus. — A home-made spirometer can be prepared 

 from a gallon bottle. The bottle can be easily graduated as fol- 

 lows. By calculation, or otherwise determine and mark the level 

 to which an ordinary water glass must be filled to contain ten 

 cubic inches of water. Now, knock the bottom out of the gallon 

 bottle, stopper the mouth, and hold the bottle in a vertical posi- 

 tion, bottom upward. With the measure provided, pour ten cubic 

 inches of water into the bottle and with a glass cutter or new 

 three-cornered file make a scratch on the ouside of the bottle at 

 the water level. Pour in another ten cubic inches of water and 

 mark the new level as before, and so proceed till the bottle is 

 completely graduated in ten-cubic-inch intervals. For this study 

 there will also be needed a tub or other large vessel of water and 

 a rubber tube of about a half inch internal diameter and two feet 

 long. The rubber tube should be provided with a short glass tube 

 to fit into one end and serve as a mouth piece for the experiments. 



2. Procedure.— ChWdvQn like to "test their lungs." After 

 filling the bottle with water by immersing it in the larger vessel 

 of water, hold it with its open end under the water level and 

 insert the rubber tube in the open end of the bottle. Now let the 

 pupils in turn fill the lungs quite completely while either sitting or 

 standing erect, take the mouth piece of the rubber tube between the 

 lips, and exhale all the breath they can from the lungs, delivering 

 it into the bottle. Just before the pupil quits exhaling see that 

 the water on the inside of the bottle is level with that on the out- 

 side and when the exhalation is complete take the reading of 

 the pupil's vital capacity from the volume marks on the bottle. 



Rinse the glass mouthpiece, after each using, in a glass of 

 fresh water, put a little hydrogen peroxide (which should be in 

 every school room anyway) on the mouthpiece, and rinse again. 

 This procedure is not only hygienic, but it will act suggestively 

 to impress the need of care in such matters. 



Repeat the experiments, this time requiring each pupil to 

 sit "on the small of his back" on a chair, as pupils are often in- 

 clined to do while studying books. Compare these results with 

 the former results. 



With upper grade pupils the following additional sets of 

 measurements can profitably be taken: (1) After taking in an 

 ordinary breath, exhale into the bottle all that can possibly be ex- 

 haled ; (2) after exhaling an ordinary breath, again exhale into 



