120 THE LAND-MARKS OF 



tubing, and bellows specially constructed for the 

 purpose of avoiding clogging with mucus — were 

 all connected and ready for use before the per- 

 formance of the operation of tracheotomy was ever 

 attempted. This was a necessary precaution, 

 inasmuch as valuable time would have been lost, 

 had the connexions between the different parts 

 of the apparatus lieen always made after the 

 trachea had been opened. Care was taken to 

 see that the channels, through which the respira- 

 tion was to be carried on artificially were clean 

 and patent. To the canula was also attached 

 a supplementary side tube, provided with a 

 stop-cock, to admit of the escape of respired air, 

 whenever it was found it was not being rapidly 

 enough discharged by the side of the tube, 

 through the mouth. The elastic recoil of the 

 lungs and atmospheric pressure were generally 

 sufficient to accomplish the act of expiration. 

 Whenever these were deemed inadequate to 

 empty the lungs, the opening of this stop- 

 cock, and compression of the chest with the 

 hands, were employed to secure efficient expira- 

 tion, whilst the pumping in of air was in no way 

 interrupted for a single instant. As regards the 

 effects of artificial respiration on animals bitten 



