202 DIGESTION. 



In July, 1865, a note was presented to the French Academy 

 of Sciences, giving the results of experiments by Dr. Krisha- 

 ber on the mechanism of deglutition as studied by auto-laryn- 

 goscopy, followed by a note on the same subject by M. H. 

 Guinier. 1 Dr. Krishaber, as the result of his observations, 

 gives the following conclusions : 



" 1st. In the act of deglutition the alimentary bolus passes 

 in one of the pharyngeal grooves, over one of the sides of the 

 epiglottis tilted by the elevation of the larynx ; the bolus 

 thus arrives at the oesophagus at the moment when, by the 

 contraction of the constrictor muscles, the pharynx is short- 

 ened and brought in front of the mass. 



" 2d. The deglutition of liquids is effected in the same 

 manner ; these passing, however, quite frequently upon the 

 epiglottis itself, which happens very rarely with solid ali- 

 ments. 



" 3d. A quantity extremely small, it is true of liquid 

 engages itself during normal deglutition around the border 

 of the epiglottis, and moistens the mucous membrane of the 

 larynx and even of the vocal cords. 



"4th. In gargling, the larynx being widely opened, a 

 larger quantity finds its way into the vocal organ. 



" 5th. An alimentary bolus may be easily tolerated in 

 the respiratory passages ; that is to say, in the larynx, as far 

 as the vocal cords, and even in the interior of the trachea. 



" 6th. The sensibility of the trachea to the impression of 

 foreign bodies is infinitely less than that of the larynx. 



" Tth. Hard and cold bodies, as, for example, a sound, are 

 not tolerated in the respiratory passages ; while any soft body, 

 which can adhere to the mucous membrane and has a tem- 

 perature like that of the parts touched, is easily tolerated in 

 the respiratory passages and kept in the trachea many 

 minutes without producing the slightest cough." 



These observations confirm the views of Longet and 

 others concerning the passage of alimentary substances 



1 Gazette Medicate de Paris, 15 juillet, 1865, p. 435. 



