CAUTERIZATION—FIRING, 81 
The Paguelin cautery (fig. 39) is based upon the property that 
platinum possesses, when once brought to a given temperature, of 
becoming incandescent in contact 
with a mixture of air and hydro- 
carbon vapors; and of remaining 
in this condition as long as the 
contact may last. The cauteriz- 
ing part is screwed on a rod, and, 
according to needs, may be a point, 
a needle or a knife. The lighting 
is simple. The cauterizing part 
is heated with the alcoholic 
lamp; after a few minutes the 
bellows is called into play. The 
platinum reddens at once. The 
ordinary Paquelin is rather weak 
for large animals. Often, if the 
animal reacts much, the point 
bends, or becomes loose, or the 
rods more or less deranged. 
The Zoocaulery (fig. 40) is more 
solid and better adapted to our 
uses. Its construction rests upon 
the power of the platinum to 
remain incandescent under the 
action of the hydrocarbonaceous 
vapors, and upon its: remarkable 
conductibility. The reservoir (A) 
contains a sponge moist with a 
small quantity of mineral essence; 
at one extremity is fitted a 
Richardson bellows ; on the other 
is screwed a peculiar branch, car- 
rying acautery in point or in line, 
whose base is perforated with lat- 
eral holes, which permit it to actas 
a siphon. A tube inside carries 
the vapors of the essence to the 
point of platinum; a screw (H) 
allows the essence to burn in the 
siphon, or prevents its reaching Fig, 38—Bourguet’s cautery, 
the siphon by the central tube. 
To make the instrument work, a small quantity of essence is. 
poured upon the sponge, that which is in excess having been ex- 
pelled, the cautery is screwed on the reservoir, and the bellows 
