MALIGNANT SOKE THKOAT. 559 



obstructions of the air-passages above the trachea, and it is 

 important, therefore, to describe it. 



The instruments needed are scissors, scalpel, and forceps, 

 needle and thread, and a tracheotomy tube. 



The selection of the tracheotomy tube is of great import- 

 ance. Those hitherto used in Scotland have had the great 

 defect of being very clumsy, difficult to hold in position, 

 unless by tying on the neck, small in bore, and long. The 

 length of these tin tubes has led, to my knowledge, to seri- 

 ous injury to the mucous membrane of the trachea, so that, 

 after having removed the tube several times in order to clean 

 it, it was found almost impossible to return it again. 



In operating, the horse or ox is kept standing, and the 

 hair clipped over the seat of the operation; an incision is 

 made in the middle line of the neck about two inches in 

 length, fairly exposing two rings of the trachea. The needle 

 is then forced through the ligament connecting the two 

 rings, and with the scalpel a semicircular piece is excised 

 from each of these. A self-fixing tracheotomy tube is intro- 

 duced, and the lip screwed in so as to prevent displacement. 

 Two or three spare lips are adapted to one instrument, inas- 

 much as the tissues are swollen immediately after the opera 

 tion, and afterwards regain their normal size. The trache- 

 otomy tube requires to be removed as often as necessary to 

 clean the parts. It is found that, in some cases, the laryn- 

 geal disease is so extensive as to prevent the permanent 

 removal of the tube, but an animal can live in perfect comfort- 

 with the tube permanently in, and prove useful for various 

 kinds of work. 



Whenever suffocation is threatened, the practitioner must 

 not hesitate in performing tracheotomy. 



