INDEX. 
! Thermometer fundamental interval of, what, p. 22 r. De- 
grees what, ibid. Bird’s Fahrenheit, p. 224. Com- 
parifoh of its fcale with M. De Luc’s, p. 225. A 
common fcale defirable, p. 228. Tables for the com- 
parifon of thermometers, p. 295. Peculiar fcales ap- 
plied to the thermometers accompanying two portable 
barometers made for the Society, p. 259. 
Thunder-houfe , experiments with it, p. 135. 
Torpedos, contrary to a received opinion, frequent the 
fhores of England, p. 464. Confiderably larger than 
thofe found in the Mediterranean, p. 465. Caught 
on the ccaft of Ireland, p. 470. Their electrical 
power, p. 471. Directions where to find, and how 
belt to preferve them alive, p. 471, 472. x 
Towns, large, injurious to population, p. 59. 
y. 
% 
Vacuum, what fort of a vacuum the phenomena of 
Nature argue, and the Newtonian philofophy demands, 
p. 271. 
Vagina and uterus, double, defcribed, p. 475 — 48c. 
Vapour of hot water, a conductor of electricity, p. 
390—396. 
Varelaz , Don Jofepb, his obfervation of the difpa- 
rition of Saturn’s ring, p. 112. 
Variation of the compafs. Vide Compafs. 
, Vegetation probably the caufe of fpnng and fummer being 
remarkably more healthy than the reft of the year, 
p. 74. 
Venus , tranfit of, oblerved at Pekin, p. 34 — 36. In the 
Sun’s parallel, oblerved at Pekin, p. 42. 
Vinegar , thrown into the air, during a ftorm, dills ir, 
according to Pliny, p. 447. 
Vitriol , native green, fpecimens of defcribed, p. 488, 
489. Why this fait and others affume a fibrous ap- 
pearance, p. 488. 
Vomits , 
