FOREIGN BODIES IN THE (ESOPHAGUS OF CATTLE. 
horns, and the head drawn up to a cross-beam, and extended as 
possible. In horses a twitch should be applied. The oesopha¬ 
geal sound is passed over the base of the tongue into the 
pharynx, and thence into the oesophagus. To avoid injury it 
must be introduced with caution. The only danger is that 
the instrument may pass into the larynx and trachea, but 
this accident is immediately evidenced by coughing and diffi¬ 
culty in breathing. Should it occur, the probang must be 
drawn back and the attempt repeated, until the instrument 
passes freely forward and can be felt at the left side of the neck 
in the oesophageal furrow—a proof that it has entered the 
oesophagus, down which it is slowly pushed until it reaches 
the foreign body, where further progress is resisted. Cautious 
attempts are made to push the obstacle onwards. The entry of 
the sound into the stomach.is attested by the cessation of re¬ 
sistance, as well as by the length of the instrument passed. 
In horses, foreign bodies like hay are sometimes so firmly 
impacted, that even this instrument cannot move them. 
(4) Extraction of foreign bodies by means of instru¬ 
ments. Amongst these is Meier’s wire snare. It consists of a 
piece of brass or copper wire, about -Jth of an inch in thick¬ 
ness, doubled and fastened by the ends to a handle, and woiks 
somewhat like the string snare, used for removing corks from 
the interior of bottles. It is introduced like the probang, the 
loop thrust behind the foreign body, which may sometimes 
be extracted by turning and pulling on the instrument. Lut 
this device succeeds only where 
the obstruction lies in the upper 
portion of the tube, and is of 
such a character that it can 
thus be snared and held. The 
methods already described are, 
however, usually more success- 
Fig. 75.— 
(Esophageal 
screw. 
ToA 6 ih ful ’ and the snai ' e is t,herefore 
screw. little used. 
The so-called oesophageal screw, for transfixing pieces of 
potato or turnip, is not of much service. The oesophageal 
forceps constructed by Delves and Hertwig are more useful 
(fi". 77). They are introduced closed, hut when the foieign 
body is felt, the jaws are opened by a screw, the instrument 
advanced, and the substance grasped and removed. These 
appliances have, however, only a narrow field of usefulness. 
Although their working is often interfered with by the 
