THE CAUTERY AND THE SETON. 
293 
The common cautery iron ( cautere cultel Zaire) is somewhat in 
tlie form of a little axe, or a rude semicircle. Its back is about 
five lines in width, and its edge more or less sharp or rounded, 
according to the purpose for which it is wanted. It is employed 
almost exclusively in the transcurrent or superficial firing; or it 
is used to destroy certain osseous or fungous or cancerous tu- 
mours, and which could not be conveniently effected by a simple 
cutting instrument, on account of the immense haemorrhage which 
would ensue. 
The conical cautery is in the form of a truncated cone, about 
an inch and a quarter in length, and its base three quarters 
of an inch in diameter. It is almost exclusively employed in the 
application of the fire by puncture. It is also proper in all those 
cauterizations, whether superficial or deep, in which it is desir- 
able to make a large opening into any tumour or abscess. 
The button , or olive or ovoid cauteries are only modifications 
of the preceding. The button or knob iron is the roundest and 
shortest ; the olive is longer, somewhat enlarged at the middle, 
more obtuse at its point, and narrower at its base ; the ovoid dif- 
fers from the others only in its bulk, and is of the shape of a 
little egg, cut across at its centre. These cauteries vary much 
in their size, according to that of the part to which they are to 
be applied. The form of the olive cautery enables it to be intro- 
duced within certain cavities, such as encysted tumours, for the 
purpose of cauterizing their interior surface. 
The cylindrical cautery has its cauterizing extremity in the form 
of a cylinder, the length and the size of which vary according to 
the size of the cavity into which it designed to be introduced. 
It may either be straight and rectilinear or curved at its extre- 
mity, or proceed from the shank in any angle that may be re- 
quired. It is often used in veterinary surgery in order to carry 
the fire to a very great depth, as in long and straight sinuses, 
the walls of which it may be necessary to stimulate or destroy. 
Th o funnel cautery ( cautere d entonnoir ) is only another name 
for the cylindrical one, when it is introduced into the diseased part 
by means of a pipe or funnel. 
The nummulary cautery ( nummulaire ), so called from its re- 
semblance to the plant nummularia , or moneywort , a species of 
Lysimachia or loose-strife , consists of an oval or round plate of 
variable size, and slightly convex on its free surface. It is de- 
signed to cauterize exposed surfaces that are level, and of a certain 
extent ; it also consumes fungous granulations, and burns large 
carious surfaces that are not very deep. It serves also for the 
cauterization by approach . 
The octagonal cautery differs only from the preceding in its 
VOL. x. q q 
