194 DICTIONARY OF THE VETERINARY ART. 



the animal advances in years, these teeth wear down, the 

 enamel disappears, and they assume a black or brown appear- 

 ance. When three years old, a change takes place in the 

 structure of the horns ; after which period these appendages, 

 like the permanent teeth, preserve the same character. Af- 

 ter the third year, the horns continue to grow as long as the 

 animal lives, and the age is indicated by the rings, or prom- 

 inences, which are easily distinguished on the horn, and by 

 which the age of the creature may be nearly ascertained, by 

 adding three years to the number of rings. 



Airing, in the management of horses, implies exercising 

 them in the open air. (See Exercise, part first.) 



Albumen. That part of the white of an egg which 

 coagulates into a solid mass when boiled ; it abounds in the 

 bones, muscles, cartilage, hoof, hair, &c. 



Alcohol. Rectified spirit. This is extensively used in 

 medicine for making tinctures. With an equal quantity of 

 water it is termed New England rum. Alcohol is a powerful 

 irritant and caustic poison, to whatever part of the horse it is 

 applied. If applied externally, it causes swelling, pain, and 

 irritation ; if given internally, it absorbs from the living parts 

 the serous or watery portion, and condenses the fibrous struc- 

 ture. Alcohol diluted in any form, acts on the horse as a 

 diuretic, causing the kidneys to secrete a large amount of 

 urine, in consequence of which they became overworked, and 

 finally diseased. It is used as a diffusible stimulant. The 

 best substitute is warm ginger tea. 



Aliment. That which nourishes the system. (See Feed- 

 ing, part first.) 



Alkalies. There are different sorts : soda, potash, and 

 ammonia, are alkalies. 



Aloes. Obtained from the aloe plant. The aloes now in 

 use as a cathartic for horses, cattle, and sheep are the Bar- 

 badoes. Pure Barbadoes aloes are of a dark brown color, 

 present a rough appearance when broken, and have a dis- 

 agreeable smell. 



Alteratives. A class of medicines that act gradually and 



