[' - 9-3 } 
See Tab. I. Fig. 5. 
A. Reprefents the Tube whichl held in my Right- 
hand, and excited with my Left, having on a Glove, 
which I find more convenient for me in rubbing 
it. I fhould obferve, that my Method then was to 
rub it fmartly for about half a fcore times up and 
down ; and then giving it one brisk Stroke, beginning 
at the End from me, upon difeharging my Hand quick 
from the Tube, the Corrufcations of Light appear’d 
as mark’d «, and / 3 , both in Size and Form: Some 
Allowance may be thought rcafonable to be made 
for one’s Judgment in fuch a Cafe, the Motion be-' 
ing fo very fudden, and the Phtenomenon fo foon 
difappearing. But I intend to repeat the Experiment 
whenever the Temperature of the Air fhall be favour- 
able, which I don’t find it to be this Morning. I for- 
got to mention, that, during this Trial, I found the 
Effluvia troublefome to my Eyes to a great Degree, 
occafioning a very|fenfible fmarting Pain,which did not 
gooff for fome time 5 tho’ I never defignedly brought 
the Tube near my Face. This was the firft time of 
ufing this Tube. 
XV. An Obfervation of a FraSlure of the Os 
Humeri by • the Power of the Mufcles only ; 
by the late Claudius Amyand, Ffq\ Ser- 
jeant Surgeon to His Majefly. 
Read March j.g g ‘1 H E outward Caufes of Fra&urcs not 
‘744 5- Jj^ bjeing fufficient to break or tear 
afundcr the broken Pieces of a fra&ur’d Knee-pan, 
in 
