THE BIT, SNAFFLE, AND CURB. 139 



Field regarding the use of biniodide of mercury, 

 ' it must be used sparingly.' 



The ordinary bit, snaffle and curb, or bit and 

 bridoon, as it is called, consists of a steel mouth- 

 piece, with what is termed a port in the centre of 

 it ; in other words, it rises up in the centre in an 

 arch. This arch or port is made high or low, 

 according as the bit is more or less severe. The 

 higher the port, the more severe its action, and 

 vice verm. The mouthpiece is made with a shank 

 or cheek at either end of it, and the two are welded 

 together. At the upper end of the shanks are 

 round eyes, to which the headstall is sewn on. The 

 lower ends are furnished with loose rings for the 

 reins. Two swinging hooks are attached (one on 

 either side) to the upper eyes, for the purpose of 

 fastening on the curb-chain, which passes round 

 under the jaw. The action of the bit is therefore 

 a double one — viz., that of the port upwards, and 

 that against the curb-chain downwards, the mouth- 

 piece forming a powerful lever against the lower 

 jaw, which is forced upwards by the curb-chain. 

 This double action may be very much increased by 

 the use of longer shanks on the bit, by a tighter 

 curb-chain, and by, as I have already remarked, a 

 higher port. 



I cannot recommend the use of anything ex- 



