SS THE HORSE. 



Dust, or gravel, or insects shall have entered the eye, and annoy the 

 horse. This peculiar muscle suddenly acts. The eye is forcibly drawn 

 back, and presses upon the fatty matter. That may be displaced, but can- 

 not be squeezed into less compass. It is forced violently towards the inner 

 corner of the eye, and it drives before it tlio haw ; and the haw having like- 

 wise some fat about the point of it, and being placed between the eye and 

 an exceedingly smooth and polished bone, and being pressed upon by the 

 eye as it is violently drawn back, shoots out with the rapidity of lightning, 

 and, guided by the eyelids, projects over the eye, and thus carries olf the 

 offending matter. 



In what way shall we draw the haw back again without muscular action 1 

 Another principle is called into play, of which we have already spoken, 

 and of which we shall have much to say, elasticity. It is that principle by 

 which a body yields to a certain force impressed upon it, and returns to its 

 former state as soon as that force is removed. It is that by which the liga- 

 ment of the neck (p. 68), while it supports the head, enables the horse to 

 graze, — by which tlie heart expands after closing on and propelling forward 

 llie blood in its ventricles — by which the artery contracts on the blood thai 

 has distended ft, and by which many of the most important functions of life 

 are influenced or governed. This muscle ceases to act. The eye resumes 

 its natural situation in the orbit. There is room for the fatty matter to return 

 to its place, and it immediately returns by the elasticity of the membrane 

 by which it is covered ; and it draws after it this cartilage with which it 

 is connected, and the return is as rapid as the projection. 



The old farriers strangely misunderstood the nature and design of the 

 haw, and many of the present day do not seem to be much better informed. 

 When from sympathy with other parts of the eye labouring under inflam 

 mation, and becoming itself inflamed, and increased in bulk, and the neigh 

 bouring parts likewise thickened, it was either forced out of its place, or 

 voluntarily protruded to defend the eye fmn the action of light, and could 

 not return, they mistook it for some injurious excrescence or tumour, and 

 proceeded to cut it out. The ^'■haw in the eyes,'' is a disease well known 

 to the majority of grooms, and this sad remedy for it is deemed the on'v 

 cure. It is a barbarous practice, and if they were compelled to walk half 

 a dozen miles in a thick dust, and without being permitted to wipe or to 

 cleanse the eye, they would feel the torture to which they doom this noble 

 animal, when afterwards employed in their service. A little patience having 

 been exercised, and a few cooling applications made to the eye while the 

 inflammation lasted, and, afterwards, some mild astringent ones, and other 

 proper ineans employed, the tumour would have disappeared, the haw 

 would have returned to its place, and the animal would iiave discharged the 

 duties required of him, without inconvenience to himself, instead of the 

 agony to which an unguarded and unprotected eye must frequently expose 

 him. 



The loss of blood occasioned by the cutting out of the haw may fre- 

 quently relieve the inflammation of the eye ; and the evident amendment 

 which follows, induces these wise men to believe that they have performed 

 an excellent operation ; but the same loss of blood, by scarification of the 

 overloaded vessels of the conjunctiva, would be equally beneficial, and the 

 animal would not be deprived of an instrument of admirable use to him. 



The eye is of a globular figure, yet not a perfect globe. It is rather 

 composed of parts of two globes. The half of the one, f, smaller and 

 transparent in front, and of the other, p, larger, and the coat of it opaque 

 behind. We shall most conveniently begin with the coats of the eye. 



