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own Eustachian tube, by which he was able to open and close it 
at pleasure. When the tube is thus opened, he described the 
noises made in singing, breathing, &c., as being much intensified, 
and during loud singing quite unbearable. In order to complete 
the reasoning logically, the sensations heard in the ordinary ear 
with a closed Eustachian tube were compared with those heard 
in the other ear when the tube was kept patent by means of a 
catheter adapted to the purpose; and in the latter case the 
modification of hearing was exactly the same as when the tube 
was voluntarily opened. The second part of the paper was 
devoted to examining the mechanism of the tube. During the - 
opening of the tube the following points were observed. The 
soft palate was unchanged in position and form, and hung 
flaccid ; this was important, showing that the tensor and levator 
palati did not participate in the action; the tongue was not 
raised, but the only observable change was the approximation 
of the posterior pillars of the fauces. The reason of this is as 
follows: The Kustachian tube presents at its inner margin a 
bluff mass of cartilage which ordinarily occludes the tube; to 
this is attached the tendon of the salpingo-pharyngeus ; below 
the latter muscle is attached to the palato-pharyngeus, which 
above arches over to meet its fellow of the other side. At rest 
the direction of the salpingo-pharyngeus is such as to press the 
mass of cartilage into the tube, but when the palato-pharyngei 
contract, the insertions of the salpingo-pharyngei are carried 
inward and a new direction given to these muscles, such that 
when they contract they tend to draw the lobe of cartilage out 
of the lumen. As the posterior pillars of the pharynx are chiefly 
made up of the palato-pharyngei, this explains their approxima- 
tion when an etiort is made to open the tube. The clicking 
sound heard at the commencement of the act of swallowing was 
pointed out to be due to the separation of the walls of the 
Eustachian tube. 
