31 
Diagnosis—purulent collection of the sinuses not due to diseased 
condition of the teeth which had been carefully examined and probably 
sequeloe of the catarrhal influenza with which she suffered 3 years ago. 
Prognosis—favorable. 
Prepared by 24 hours diet, she was on the morning of the 23d, 
brought forward for the operation of trephining to be performed 
standing up; but she defended herself so much that it was found nec¬ 
essary to throw her. First an incision about 2K inches long was made 
parallel to the maxillary spine, and another brought upon it obliquely 
from the inner angle of the eye; the skin, muscle and periosteum care¬ 
fully dissected and pushed upwards, the facial portion of the zygomatic 
bone was trephined and the sinus open. A thick congested membrane 
made its appearance which being excised, allowed the pus to escape. 
So as to clean the cavity an injection of carbolized water was made, 
and at the bottom of the sinus a bony surface, enamel in appearance 
was felt. Being loose in the sinus, removing it was tried, but its 
enormous size would not allow it to pass through the opening of the 
bone, which had to be enlarged with bone forceps; after much difficul¬ 
ty it was brought out. Pus then was discovered underneath which 
was also washed out, and then another bony tumour of the same kind— 
this second was followed by a third; both being removed, at last the 
cavity was found perfectly empty and clean. Being thoroughly 
washed, the wounds were brought together by stitches—a tent of oakum 
left at the commissure of the two incisions—compresses of cold water 
applied and the mare taken to her stall. 
A large number of small broken pieces were found and saved for 
further examination. The three large pieces were each surrounded by 
a large and thick, highly vascular membrane which was quite adherent 
to the outer surface of the three lumps, and also to the mucous of the 
sinus; they were irregular in shape, but quite smooth on their outer 
surface. Their appearance is white with a slight yellowish hue—a 
small piece, thinned on a grinding stone, and placed under the micro¬ 
scope shows very plainly the bone-cells, a mass of earthy substance and 
what I fancied masses of exagonal lozenges analoo-ous to those of 
enamel nature; also the striated appearance of the dentine. 
March 24th. The parts which had begun to swell in the afternoon 
after the operation, were quite sore and swollen; on removing the oak¬ 
um, very offensive, dark colored matter escaped. The wounds were 
well washed and treated by carbolic injections three times a day; cold 
water compresses. 
25th. Discharges through the nose slight; swelling smaller; very 
offensive odor of necrosed bone. 
26th. Swelling increased; some stitches give way. 
