comparative lesions of brain wounds. 
361 
no time subsequent to the injury gave evidence of mental impair¬ 
ment. Daring a lapse of nearly forty years this lesson has passed 
almost unheeded, save as a cariosity. 
The two following cases occurred in the practice of the father 
and uncle of the writer, and were matters of individual observa¬ 
tion as a student; they are reproduced from notes that, along 
with the breech-pin in question, came into my hands on the death 
of the second physician, named Dr. Geo. B. Willson. 
2. “ June 4th, 1859. Dr. S. and myself were summoned to 
see !S. W. B. a cabinet maker, age 22, wounded in the head by a 
circular saw. Found him at the shop were the accident occurred, 
and sitting on a chest unsupported and unaided, and perfectly 
rational. He volunteered the information that after adjusting a 
belt beneath the table, in the act of returning he brought his head 
in violent contact with the rapidly moving saw—a disk sixteen 
inches in diameter, one-fourth inch in set of teeth, revolving at the 
rate of 3,800 per minute. It was an affair of a second only ; the 
impulse of the disk felled him to the floor, but he immediately 
recovered, backed out, rose, seated himself on the chest where we 
found him, and summoning a fellow workman dispatched him 
for surgical aid. 
“ Fifteen minutes may have elapsed between the receipt of 
the injury and our arrival. There had been considerable bleeding, 
judging from the clots of blood on his neck and the stains upon 
his clothing and the floor; but this had been controlled by a work¬ 
man’s apron tightly wrapped about the head. He denied any 
sense of pain save at the moment of coughing, which just began 
as he raised himself from the floor, and now was most persistent, 
dry and hacking. 
On removing the cloth from his head a wound seven inches in 
length, above three inches in depth and corresponding to the “ set ” 
of the saw, was revealed, extending immediately across the sag 
getal suture and dividing the longitudinal sinus, falx and branches 
of the middle meningeal artery; beginning at the superior tern 
poral ridge of the left parietal, it terminated on a level with the 
tip of the right ear. While coughing, each inspiration caused the 
brain to shrink from the skull, admitting air beneath the dura 
