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particularly deferving the attention of the Society, as it 
may be of fervice in many cafes different from this. 
Tab. XIII. A 13 C is a double fcrevv, the turns of 
whichare in contrary directions ; thefe fcrews are moved 
by the handle A, in fuch a manner that, when each 
of them, B C, isfcrewed into its correfpondent worm 
D E, one motion of the handle A brings the two 
worms D E nearer together j and a contrary motion 
fets them at a greater diftance. 
I invented this inflrument about fifteen years ago, 
to comprefs the wounds of thofe, who had been cut 
for the ftone, fo as to prevent the paffage of the 
urine, and thereby haflen the clofing of the incifion. 
To apply it properly in thefe cafes, I paffed a collar 
faffened to the neck of the patient, through the ring 
F, in the upper fcrew worm, and the bandage which 
fupported the dreflings, through the ring G, in the 
lower fcrew worm ; and I have frequently experi- 
enced the fuccefs of this manoeuvre. 
In the year 17 < 77 , I made ufe of it to preferve an 
arm, fraCtured near the fhoul-der-joint, in its natural 
flate of extenlion, by fattening the two flat rings F G, 
in the two pieces of wood FI Ij placing FI under 
the arm-pit, and I upon the fore-arm againft the 
bend of the elbow ; and keeping the fore-arm bent 
by the fling K L. 
I alfo applied this inflrument in the prefent cafe ; 
and in order to aflifl in giving the proper direction, 
and necefiary lolidity to the part, I fupported the 
arm with a vambrace, or half-canal, made of one 
very thin piece of wood, which furrounded two 
thirds of the circumference of the limb. The whole 
was 
