238 PHILOSOPHICAL TKANSACTIONS. [aNNO 1728. 



half white ; which, though it is not of much use in this operation, is very much 

 so in couching needles; we being thus able to judge of their position, when we 

 do not see them. 



Fig. 6 represents an instrument to keep open the eye-lids, g is a bit of iron ; 

 which, as it is moved backward or forward, the instrument opens or closes. 



Of several Stones found in the Kidneys of a Person, opened by Mr. John Dobyns, 

 Surgeon and Lithotomist to St. Barlholomeius Hospital and F. R. S. N° 402, 

 p. 452. 



Mr, Laurence, a gentleman about 40 years of age, had for near 20 years a 

 complaint in his kidneys ; making bloody urine on any extraordinary motion, 

 but free from the great pain, and all other symptoms usually attending nephri- 

 tic cases. However, on opening the kidneys after his death, there was in each 

 a stone of an extraordinary size and figure, besides 100 smaller. 



Fig. 7, pi- 5, shows one of them denudated, as taken from the pelvis of the 

 right kidney : a is tliat part which had branched into the ureter, and totally 

 obstructed its channel ; bbb the eminent parts of it ; cc that part which filled 

 the capacity of the pelvis. 



Fig. 8 represents the stone taken from the left kidney : a is that part which 

 had protruded itself into the upper part of the ureter, but did not totally plug 

 it up, by which means the urine had a passage; bbbb the eminent parts, which 

 branched into the fistulas meinbranaceae ; cccc the body of the stone, which lay 

 in the pelvis of this kidney. 



On the Aurora Borealis seen Oct. IQ, N. s. 1726. By several Persons. 

 N° 402, p. 453. 



Mons. Gaudin, in a letter from the Observatory at Paris, dated Oct. 20, 

 N. s. 1726, writes, that he saw it first at half past 7 in the evening, forming 

 at that time a luminous arch, with another somewhat darker under it, which 

 extended itself almost from sun-set to moon rise, and was raised above the 

 horizon about 25 degrees ; from whence shot out from time to time luminous 

 streams about 10 degrees above it. At half past 8, the number of these streams 

 vastly increased, covering all the heaven, excepting the height of 20 degrees 

 opposite to it : but towards the zenith there remained a circular space which 

 was never covered by them, though there wanted not a constant succession. 

 These appearances continued very strong till half after 10; when they began 

 to decline, and entirely disappeared about 2 in the morning. 



Mons. Maraldi, in a letter dated at Thiers, Oct. 20, 1726, n. s. two leagues 



