of which is, that in chewing, the under jaw 

 only moves ; which, being placed as far out- 

 wards as possible, and moved inwardly again, 

 the pressure increases till the teeth are close ; 

 and the jaw being then moved crosswise, the 

 force gradually lessens, till the jaw is extended 

 as far as it can go; the friction, therefore, is 

 least powerful at eace side ; and the motion of 

 the jaw beginning from the outward edge, and 

 inoving obliquely inward, the outward edge of 

 the fore teeth suffers but little. The pressure 

 being chiefly on the inward edge, the teeth of 

 the upper jaw are much worn *, but in tlior.e of 

 the under, the outward edge sutfers rn^st, 

 while the inward edge remains sharp and un- 

 touched. With respect to the grinders, the 

 outw^ard edge of the under teeth and the in- 

 ward edge of the upper, are chiefly used, and 

 consequently are most worn. The counte- 

 nance of an old horse also looks heavy, as was 

 before observed, and they become hollow 

 above the eyes-, but this will frequently be the 

 case with young horses that are produced from 

 Old stallionfe. 



