DICTIONARY OF THE VETERINARY ART. 265 



Opiates. (See Narcotic.) 



Opium. A narcotic vegetable poison. Mr. Coleman 

 "thought, from some experiments made at the veterinary 

 college, that opium has no apparent influence over the ner- 

 vous system of the horse, and that it does not alleviate pain." 

 Dr. White says, " I think that opium, as to its effect on the 

 horse, does not possess that soothing anodyne, and soporific 

 quality, for which it is justly distinguished in human medi- 

 cine." Opium always tends to depress the vital organs in 

 proportion to its quantity. 



Opodeldoc, or Soap Liniment. A solution of soap and 

 camphor in spirits of rosemary. 



Optic Nerve. The nerve on which sight depends. 



Orbit. The socket of the eye is thus named. 



Organic. A disease is said to be organic when any par- 

 ticular organ of the body is affected. 



Ossification. Ligaments and cartilages sometimes become 

 bony, especially those ligaments which unite the splent to the 

 cannon bones, and the lateral cartilages of the foot. 



Ovaries. Two appendages to the womb, or uterus, which 

 are cut out in the operation of spaying. 



Overreach. A horse is said to overreach, or overlash, 

 when he wounds the fore heel with the hind foot. 



Overwork. Many of the diseases of horses originate in 

 overwork. 



Pace. The peculiar manner of motion, or progression. 

 The natural paces of the horse are, the walk, trot, and gallop, 

 to which some add the amble. 



Palate. The upper part or roof of the mouth. 



Palliative. Medicines and operations by which diseases 

 appear to be relieved, but not cured. However desirable 

 palliatives may be in the diseases of the human body, they 

 are seldom satisfactory in the diseases and lameness of horses. 



Palpitation. Beating of the heart against the breast 

 bone, or ribs. 



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