POLL-EVIL. 157 



the food passed over it, than it rises again by its own elasticity, and leaves the upper 

 part of the v.indpipe once more open for the purpose of breathing. The voice of ani 

 mals is produced by the passage of air through this aperture, communicating certain 

 vibrations to certain folds of the membrane covering the part, and these vibrations 

 being afterwards modified in their passage through tlie cavities of ihe nose. In order 

 to understand the diseases of these parts, the anatomy of the neck generally must be 

 considered. 



CHAPTER V. 



THE ANATOMY AND DISEASES OF THE NECK AND 

 NEIGHBOURING PARTS. 



The neck of the horse, and of every animal belonging to the class mammalia, except 

 one species, is composed of seven bones called vertebrae., moveable or turning upon 

 each other (see cut, p. 'o^). They are connected together by strong ligaments, and 

 form so many distinct joints, in order to give sufficiently extensive motion to this 

 important part of the body. The bone nearest to the skull is called the atlas (see cut, 

 p. 68, and g, p. 72), because, in the human being, it supports the head. In the horse 

 the head is suspended from it. It is a mere ring-shaped bone, with broad projections 

 sideways; but without the sharp and irregular processes which are found on all the 

 others. The pack-wax, or ligament, by which the head is principally supported 

 (/' P* '^"^)' ^"^ which is strongly connected Avith all the other bones, passes over this 

 without touching it, by which means the head is much more easily and extensively 

 moved. The junction of the atlas with the head is the seat of a very serious and 

 troublesome ulcer, termed 



POLL-EVIL. 



From the horse rubbing and sometimes striking his poll against the lower edge of 

 the manger, or hanging back in the stall and bruising the part with the halter — or 

 from the frequent and painful stretching of the ligaments and muscles by unnecessary 

 tight reining, and, occasionally, from a violent blow on the poll, carelessly or wan- 

 tonly inflicted, inflammation ensues, and a swelling appears, hot, tender, and painful. 

 It used to be a disease of frequent occurrence, but it is now, from better treatment of 

 the animal, of comparatively rare occurrence. 



It has just been stated, that the ligament of the neck passes over the atlas, or first 

 bone, without being attached to it, and the seat of inflammation is between the liga- 

 ment and the bone beneath ; and being thus deeply situated, it is serious in its nature 

 nnd difficult of treatment. 



The first thing to be attempted is to abate the inflammation by bleeding, physic, 

 and the application of cold lotions to the part. In a very early period of the case a 

 blister might have considerable effijct. Strong purgatives should also be employed. 

 By these means the tumour will sometimes be dispersed. This system, however, 

 must not be pursued too far. If the swelling increases, and the heat and tenderness 

 likewise increase, matter will form in the tumour; and then our object should be to 

 hasten its formation by warm fomentations, poultices, or stimulating embrocations. 

 As soon as the matter is formed, which may be known by the softness of the tumour, 

 and before it has time to spread around and eat into the neighbouring parts, it should 

 be evacuated. Now comes the whole art of treating poll-evil ; ihe opening into the 

 tumour must be si> con/rived that all the matter shall run nut, and continue afterwards to 

 run out as quickly as it is formed, and not collect at the bottom of the ulcer, irritatino 

 and corroding it. This can be elTected by a setnn alone. The needle should enter 

 at the top of the tumour, penetrate through its bottom, and be brought out at the side 

 of the neck, a little below the abscess. Without anything more than this, except 



