198 THE ]\rUSCLES, NERVES, AND BLOOD-VESSELS. 



througli them, and increases in loudness, as tlirough the windings of a 

 French horn. 



The extension of the nostril at the lower part of these cavities is an 

 important part of the face, and intimately connected with breeding, courage, 

 and speed. The horse can breathe only throtigh the nose. All the air 

 which goes to and returns from the lungs must pass through the nostrils. 

 In the common act of breathing, these are sufficiently large ; but when the 

 animal is put on his speed, and the respiration is quickened, these passages 

 must dilate, or he will be much distressed. The expanded nostril is a 

 striking feature in the blood-horse, especially when he has been excited and 

 not over-blown. The sporting man will not forget the sudden effect which 

 is given to the countenance of the hunter, when his ears become erect, and 

 his nostrils dilate as he first listens to the cry of the hounds, and snorts, 

 and scents them afar off. The painful and spasmed stretching of this part, 

 in the poor over-driven post-horse, will show how necessaiy it is that the 

 passage to the lungs should be free and open. The nostrils should not only 

 be large, but the membranous substance which covers the entrance into the 

 nose should be thin and elastic, that it may more readily yield when the 

 necessity of the animal requires a greater supply of air, and afterwards 

 return to its natural dimensions. Therefore, nature, which adapts the 

 animal to his situation and use, has given to the cart-horse, that is seldom 

 blown, a confined nostril, and surrounded by much cellular substance, 

 and a thick skin ; and to the horse of more breeding, whose use consists 

 in his speed and his continuance, a wider nostril, and one much more 

 flexible. 



The inhabitants of some countries were accustomed to sHt the nostrils 

 of their horses that they might be less distressed in the severe and long- 

 continued ejtertion of their speed. The Icelanders do so to the present 

 day. There is no necessity for this, for nature has made ample provision 

 for all the ordinary and even extraordinary exertion we can require fi-om 

 the horse. 



Some very powerful muscles proceed from different parts of the face to 

 the neighbourhood of the nostrils, in order to draw them back and dilate 

 them. Four of these are given in the next cut, which is introduced to com- 

 plete our present subject, and which will be often refen^ed to in the course 

 of our work ; I. m, o, and p, are muscles employed for this purpose. 



There are also four distinct cartilages, attached to the nostrils, which, 

 by their elasticity, bring back the nostrils to their former dimensions, as 

 soon as the muscles cease to act. The bones of the nose (p, p. 145) are 

 also sharpened off to a point, to give -wider range for the action of the 

 muscles ; while the cartilages are so contrived, as not only to discharge 

 the office we have mentioned, but to protect this projection of bone from 

 injury. 



There are two circumstances, which, more than any others, ^vill enable 

 not only the veterinary surgeon, but the o^vner of a horse also, accurately to 

 judge of the character and degree of many diseases, and to which very few 

 persons pay sufficient attention ; these are the pulse, of which we shall pre- 

 sently speak, and the colour of the membrane of the nose. It is the custom 

 of most veterinary surgeons and horse-men to lift the upper eyelid, and to 

 form their opinion by the colour which its lining presents. If it is very red, 

 there is considerable fever; if it is of a pale pinkish hue, there is little 

 danger. The nose, however, is more easily got at ; — the surface presented 

 to the view is more extensive ; — its sympathy with almost all the important 

 organs is greater ; — and the changes produced by disease are more striking 

 and more conclusive. Let the reader first make himself well acquainted 

 with the uniform pale pink appearance of that portion of the membrane 



