58 The Philippine Journal of Science mis 



the mouth, at which instant the intrapulmonic pressure must 

 have already fallen to about normal, as Plate I, fig. 1, and Plate 

 II, fig. 2, seem to indicate. When the cork began to move, it 

 did so slowly, and its movement did not exhibit any indication 

 that extra forcible expiration occurred following the act of 

 vomiting.^ The absence of air current in the respiratory pas- 

 sages during the act of vomiting is shown most decisively if 

 emesis sets in when the cork is about in the middle portion of 

 the glass tube. 



The foregoing results point conclusively to the impossibility 

 of removing foreign bodies from the trachea by the use of apo- 

 morphine. It seems, moreover, that a foreign body in the re- 

 spiratory passages below the larynx may, in reality, be driven 

 farther in during the early stage of vomiting because of the 

 descent of the diaphragm and closure of the glottis, which in 

 turn give rise to the rarefaction of the air in the thoracic 

 cavity and a rushing of the air into the deeper portion of the 

 lungs. When tenacious mucous plugs are present in the bron- 

 chioles, this may be more than counterbalanced by the stimulat- 

 ing effect of apomorphine on the secretion " and peristalsis ^ of 

 the bronchioles, which may loosen and facilitate the expectora- 

 tion of the plugs after vomiting. 



SUMMARY AND CONCLUSIONS 



Transient stimulation followed by paralysis of the vomiting 

 center occurs when nonansesthetized dogs are asphyxiated by 

 shutting off the air from the trachea. 



Partial asphyxia, such as is produced by reducing the lumen of 

 the trachea to a circular opening of about 1.5 millimeters in 

 diameter, shortens the time required for the emetic action of 

 apomorphine. This is due, presumably, to the increased irri- 

 tability of the vomiting center to apomorphine. 



The intrapulmonic pressure is raised by the convulsive con- 

 traction of the abdominal wall which occurs during vomiting, 

 and the rise of pressure seems to begin before the passage of 

 vomitus through the oesophagus. 



The glottis remains closed during the act of vomiting, as 

 shown by the method above described. This conclusion is fur- 



' Of. starling, Schafer's Text-book of Physiology. Young J, Pentland, 

 Edingburg & London, (1898) 2, 325. 



'Henderson and Taylor, Journ. Pharmacol. & Expt. Therap. (1911-12), 

 2, 153. 



' Meyer and Gottlieb, Die Experimentalle Pharmakologie. Dritte Auf- 

 lage. Urban & Schwarzenberg, Berlin und Wien (1914), 329. 



