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THE CAUTERY AND THE SETON. 
1. Before we proceed to the application of the cautery, the 
horse should always be prepared by some days’ restricted regi- 
men, especially if he is of an irritable temper. When practicable, 
the operation should be performed in the morning, and while the 
horse is fasting. If the animal must be fired in the day-time, 
he should not have been permitted to eat during some hours pre- 
ceding the operation. 
2. Some veterinary surgeons assert that there is no necessity 
to cut the hair from the surface to which the iron is about to be 
applied ; others, and we are among the number, cut the hair as 
closely as possible, for the cautery may be then more accurately 
and effectually employed. 
3. It is always advisable, before the operation is begun, to ex- 
amine most carefully the limb that is to be operated upon, to 
consider the state in which it actually is, and to be perfectly as- 
sured of the parts that most require the fire, and on which it 
ought to be, in a manner, concentrated. 
4. Four irons will ordinarily suffice, if the operation proceeds 
in the usual manner. They should not be of a white heat ; the 
temperature marked by an obscure cherry-red heat will usually 
be preferable. The best combustible for heating the irons is dry 
charcoal : coal covers the cautery with a thick vitreous matter, 
and roughens the edge. 
5. Every thing being ready, the animal must be cast. An 
assistant places the irons in the fire, and as they become suffi- 
ciently hot, detaches the scales either with a file, or by rubbing 
the iron on a stone, and sends them to the operator by another 
assistant, who carries them as quickly as he can, offering the 
handle to the operator, and then waiting for the signal to get 
another ready. Every time that the operator receives a newly 
heated iron, he examines the sharp edge of it, and assures him- 
self that it is sufficiently thick and smooth. 
6. The lines ought to be lightly traced at first with an iron 
moderately heated, and with a view to destroy any remains of 
the hair, and not so deep as that they cannot be rectified, if they 
were not accurately drawn at first. The temperature of the se- 
cond iron should be a little higher. As the colour of the instru- 
ment becomes dull, the operator calls for another, and he passes 
that also over the part, line by line, until the skin is sufficiently 
burned, and the cautery has been applied with equal severity over 
every part. 
7. The operator should not use too heavy an iron, nor ought 
he to press on it; but every thing should be done with a light 
hand: the instrument, however, should move slowly, and pass 
and repass many times over each line, in order to transmit the 
