Vocal Cords in Quiet Respiration in Man, fyc. 409 



sake of completeness only, as it will be seen from the table that they 

 give no direct measurements for quiet respiration, which in the 

 present investigation alone is of importance. Moreover, the passages 

 in their works in which the statements in question occnr may be 

 differently interpreted.* Secondly, only Luschka and Von Bruns 

 give numbers comparing the different positions as seen daring life 

 and after death. Thirdly, it does not appear, from the statements of 

 any of the authors quoted, whether their numbers are outcomes of 

 direct measurements or of mere estimates, and even if the former, upon 

 how many measurements their statements are based. Finally, and 

 this is no doubt the most important objection against drawing definite 

 conclusions from the above table, it is not stated in the writings of 

 any of the authors quoted whether the numbers given by them, 

 be they the outcomes of direct measurements or not, refer to the 

 actual width of the glottis or to the apparent one, as seen in the 

 graduated mirror. 



I will, therefore, draw no inferences whatsoever from this table, 

 and only direct attention to the facts that, with all these shortcomings, 

 (1) the minimum of the numbers given for the position of rest by 

 Luschka and Yon Bruns is larger than the maximum of the width 

 after death, as given by all the observers who have expressed this in 

 numbers (Luschka, Von Bruns, Frankel, Merkel, and Hnschke) ; and 

 that (2), even if we were to take into consideration the rhythmical 

 excursions as given by Solis Cohen and Mackenzie, their minima 

 would just correspond to the stated maxima of the width of the 

 glottis in the dead body. 



As I felt, however, that the evidence on this point, for the reasons 

 above given, was by no means conclusive, I began this investigation 

 by making a large number of direct measurements of the width of 

 the glottis in adults during quiet respiration and after death. The 

 number of my observations on living persons amounts to fifty, that 

 on dead bodies to twenty-five.f I need not say that in every instance 

 the measurements were made with great care, strictly in accordance 

 with the rules enumerated in a foregoing paragraph, and that in 

 every case of observation of the living subject the graduated mirror 

 was repeatedly introduced, and the average taken from the numbers 

 gained. It may, however, here be stated that in one and the same 

 person, unless his attention be called to his mode of breathing or 



* Solis Cohen says, " The space across will vary ordinarily from three to six lines, 

 but when widely dilated by a deep inspiration it may be from six to ten lines, 

 leaving a space large enougn often to admit a good sized finger." Mackenzie says, 

 " On inspiration they (tb^ vocal cords) appear almost to touch each other at their 

 anterior insertion, but to be separated from i to i an inch posteriorly." 



t For some time I examined the larynges of all adults of whom a post-mortem 

 examination was made in St. Thomas's Hospital. 



VOL. XLYIII. 2 F 



