294 
THE CAUTERY AND THE SETON. 
assuming this form, and having its surface less extensive. It is 
used for the same purposes. 
The circular , annular, or docking (Jjrule- queue) iron, is used to 
arrest the haemorrhage after amputation of the tail. It is in the 
form of a ring. The hollow receives the portion of the bone 
which projects after the amputation, while the iron, at a red or 
white heat, rests on the surrounding muscle. 
The temperature of the iron depends on the object which is to 
be accomplished. In general, these instruments irritate more and 
destroy less the parts to which they are applied in proportion to 
the less intensity of the heat ; and they irritate less and destroy 
more in proportion as the heat is increased. Thus the cautery 
iron at a grey heat is a violent irritant, and causes intense pain ; 
while the application of the same at a white heat is far less 
painful. The first does not disorganize the parts, or does not 
destroy them long ; the second destroys the organization of the 
tissue, and with it every vital property the moment it is employed. 
This should, more than it generally does, guide the veterinarian, 
and teach him to proportion the temperature of his cautery to 
the effect that he means to produce. 
The mode of applying the cautery may be divided into the 
objective, the superficial, and the deep. 
The objective cautery , or the cautery by gradual approach, is 
the one least employed. It consists in gradually approaching 
the diseased part with the heated iron, without actually touching 
it. Under its influence the tissues become reddened, and some- 
what engorged by means of the flow of blood to them. A true arti- 
ficial inflammation is excited, the symptoms of which gradually 
subside, leaving a greater development of vital energy in the part. 
Sometimes one cauterization does not suffice, and the parts re- 
lapse into their natural state of debility. It is then necessary to 
repeat the employment of the cautery, until some permanent 
effect is produced on the circulation and function of the part, and 
an evident sanitary process is set up. This mode of cauterization 
is applicable to certain atonic ulcers. It is used with some appa- 
rent success, when repeated four or five times in some cases of in- 
termittent ophthalmia. It is also useful in phymatosis (tubercular 
disease), and other analogous chronic complaints. The recorded 
cases of the benefit derived from the objective cautery are not as 
yet very numerous, but they will be gradually multiplied. The 
objective cautery, by means of the rays of the sun concentrated 
in their passage through a lens, has no pretension superior to the 
common cautery. That accomplished by burning charcoal, 
brought by means of the forceps within a certain distance of the 
ulcer or part to be operated on, has this serious inconvenience, 
