Studies on Lung Volume 



151 



Third. The amount of actual loss in acuity of hearing was 

 not proportionate to the loudness of the tinnitus. After hearing 

 returned to normal the tinnitus continued for at least twenty- 

 four hours. 



Fourth. A tinnitus produced by a continued loud sound gives 

 rise to similar sensations of fullness in the ears and does not 

 bear any definite pitch relation to the frequency of the sound 

 causing the condition. The acuity of hearing was not impaired 

 after three and one half hours exposure. 



Fifth. Recovery of normal hearing after ingestion of quinine 

 occurs in 24 to 36 hours. 



Sixth. The toxic affect of quinine influence not only the 

 auditory sense, but the entire nervous apparatus is affected so 

 that definite readings with larger doses are not possible. 



Seventh. We present herewith a study in the application of 

 modern methods in the measurement of acuity of hearing. The 

 disadvantages shown in this accurate method practically rule out 

 the watch tick tick and the tuning for K tests in their application 

 to minimum audibility. 



70 (2030) 



Studies on lung volume. IV. Investigations on admixture of air 

 in the lungs with other air. 



By CHRISTEN LUNDSGAARD and KNUD SCHIERBECK. 



[From the Medical Clinic of the University of Copenhagen, Den- 

 mark.] 



Several methods of importance for the study of the physiology 

 and pathology of respiration and circulation require (1) that it 

 is possible to produce full admixture of air within the lungs with 

 other air and (2) that the exact conditions necessary for full 

 mixture can be ascertained in a given case. This and the follow- 

 ing paper is a short report of experiments dealing with questions. 



Technique. 3 liters of oxygen ( Allen-Pepys' method) or of 

 hydrogen plus oxygen (Davy-Durig's method) are introduced in 



