Unilateral Removal of the Otic Labyrinth. 133 



pressure. A small-sized rubber bag is then attached to the hori- 

 zontal portion of the tracheal cannula. The bag is thoroughly 

 exhausted. The cocks of the pleural cannulae are now opened. 

 At the end of an expiration, the upright portion of the tracheal 

 cannula is quickly clamped, the air pressure is turned on and the 

 bag opened. A mercury valve is provided so that the desired 

 pressure cannot be exceeded. The lungs collapse. Their contents 

 are forced into the trachea and rubber bag. A portion of the air 

 remains in the bronchi and trachea. The sample therefore ap- 

 proximates the total air. 



It has been found that when no precaution is observed to 

 maintain the body temperature, very uniform percentages of 

 carbon dioxid may be obtained. Five experiments have been 

 made thus far. In each experiment the carbon dioxid exhibited 

 uniformity, either immediately or after a preliminary period of 

 fluctuation. The periods of constancy ranged from one and a 

 half to three and a half hours. In three experiments in each of 

 which 8 determinations were made, the maximum deviation from 

 the average was ± 3.0-3.5 per cent.; in one experiment, in which 

 7 determinations were made, the maximum deviation from the 

 average was ± 2.4 per cent.; in another experiment, in which 5 

 determinations were made, the maximum minus deviation was 

 0.5 per cent, and the maximum plus deviation 1.4 per cent. 



80 (1258) 



On the compensation of the ocular and equilibrium disturbances 

 which follow unilateral removal of the otic labyrinth. 



By A. L. Prince (by invitation). 



[From the Physiological Laboratory, Yale Medical School.] 



It has been shown 1 that the disturbances of function which 

 follow unilateral destruction of the otic labyrinth are of short 

 duration in higher mammals, the torsion of the head being the 

 only persistent symptom. In very young animals, the conditions 



1 Wilson and Pike, Phil. Trans. Royal Society, London, 1912, Series B, CCIII, 

 p. 127. 



