770 THE EXTERIOR OF THE HORSE. 



The artificial cavity is then generally colored black by the applica- 

 tion of nitrate of silver, so as to give to it the appearance of what in 

 the adult tooth is called the bean, the mark. 



But if we take the precaution to wipe the abundant saliva from the 

 dental tables w^hen the horse is offered for sale, it will be easy to detect 

 this imitation. The following are its characteristics (Plate XXXIV.) : 



1st. If, after having separated one lip from the other, it is seen 

 that the incisors of the two jaws do not exactly correspond, it is evi- 

 dent that their surface of friction has been rasped without shortening 

 the molars in the same proportion. 



2d. If, after having seized the tongue in order to separate the in- 

 ferior jaw from the superior, cavities are observed upon the dental 

 tables, it is necessary to ascertain if their presence is in relation with 

 the form of the table ; finally, it must be determined whether they are 

 natural or artificial. We must be certain as to the latter point. 



a. When the cavity is natural, it is surrounded by a border of 

 enamel which is in relief above the dental table. This relief results 

 from the fact that the two substances which essentially compose the 

 tooth (the enamel and the dentine) do not offer the same resistance to 

 wear. 



6. On the contrary, when the cavity is aiiijicial, its periphery is not 

 surrounded by enamel, and the line which surrounds its opening or 

 entrance is not in relief upon the table. Thus it can be very easily 

 recognized by sight as well as by touch. 



§ 3. Rasping of the Corner of the Superior Jaw, 



We know that often at the age of six years the superior corners 

 present a well-defined notch on their table, due to the fact that the whole 

 of their table is not worn against that of the inferior. Many persons 

 recognize the notch, and horse-dealers especially are well aware that if 

 this notch be removed while the teeth are still fresh, the horse will 

 seem younger than he really is. They remove it with the rasp. This 

 trick, which is not very often practised, and of which we have seen 

 some examples, is of no great importance ; such manipulation may be 

 easily discovered by finding the marks of the rasp upon the tables of 

 the superior corners. 



