BY ETHEL C. PlNKERTON^ 



869 



A more extensive series of figures lias been oljtained in the first 

 set of experiments, in which glass-wool was placed in the brass 

 tube. The results, arranged according to the depth of the expira- 

 tion, which varied from IJOO c.c. to 1025 c.c, are recorded in Table 

 iii. 



Table iii. 



The figures show that the expired air, which is collected at a 

 distance of 200 cm. from the moutiipiece, contains more oxygen 

 and less carbon dioxide than that leaving the lungs at the end of 

 expiration. In two exi)eriments, viz., Nos. 7 and 22, there appears 

 to be no evidence of any change in composition in the portion of 

 expired alveolar air examined. In experiment 2, the difference 

 amounts to 0-o6% oxygen, and to 0-22% carbon dioxide, the 



