‘INDEX. 515 
To exhibit the gradual rarefa&ions of the air at all 
heights above the earth’s fnrface, in any given tempera- 
ture, by a feries of powers, p. 273. 
Any two different temperatures being affigned to find the 
height above the earth’s furface, where the air’s denfity 
is the fame in the one as in the other, p. 283. 
where the preffure is fame, p. 288. 
Platina , refult of an elecftrica! experiment on, p. 416. 
Purcell, Profeffor John, his defcription of a double uterus 
and vagina, p. 474, 475. Similar inflances mentioned 
by other anatomifts, p. 479. 
Pyrites , various fpeeimens of, defcribed, p. 489. 
Q, 
Quadrupeds , grar.ivorous and carnivorous, different for- 
mation of their ftomachs, p. 314. 
Quebec , eclipfes of Jupiter’s fatellires obferved there, p. 176. 
Quinarius, a.vQry ancient one defcribed, p. 319. 
Quickfilver, the quantity of its expanfion by heat, p. 
238, 239. Difference between Boerhaave and De Luc 
reconciled, p. 242. 
R. 
Rain, quantity of, at Manchefler and other places, p. 64. 
Repulfion , none between water and air, p. 452. A natural 
one between the particles of oil, 453. 
Rivers , few of any confideration in the country of La- 
brador, p. 37 5. 
Piemans borrowed their monogrammatic way of writing 
from the Etrufcans, p. 322. 
Ranayne , Mr. his opinion upon points and knobs, p. 144. 
Royton, flare of population, duration of life, &c. p. 61. 
Comparative furvey of Royton and Eaftham, p. 62, 63. 
Uuu 2 Salts, 
