[ 459 ] 
7i. Extraft of a regifter of the barometer, thermometer, and rain, at Lyndon in 
Rutland, by Mr. Barker, p. 281. 
Refraftion. Law of, explained, p. 58. 
Relazionc di un a nuova pioggia, feritta dal Conte de Gioeni abitante della 3 s reggione 
dell’ Etna, p. 1. 
Rovcley -rag-Jlonc . See Mineral Subjiances. Where found, p. 329. Its more obvious 
properties, p. 33a. Experiments on, ibid. Conclufions from thofe experiments, 
p. 332. Might probably be ufed advantageoufly as a flux for calcareous iron ores, 
Saline Subjiances. Continuation of the experiments and obfervations on the fpecifle 
gravity and attra&ive powers of various faline fubflanccs, by Mr. Kirwan, p. 179. 
Some miftakes in Mr. Kirwan’s laft paper rectified, ibid. Tables conftru£fed in con- 
fequence thereof, p. 182. et feq. The quantity of pure acids taken up at the 
point of faturation, by mineral alkali, examined, p. 1 S 8 - Ditto by the volatile 
alkali, according to the experiments of Dr. Pricftley, p. 191. Ditto by calcareous 
earth, p. 192. Ditto by magneua or muriatic earth, p. 193. Ditto by earth of 
allum or argillaceous earth, p. 194. Ditto by phlogifton, p. 195. Of the quan- 
tity of phlogillon in nitrous air, p. 21 1. Of the quantity ot ditto in fixed air, p. 
213. Nature and origin of fixed air examined, ibid. Various opinions concerning, 
and experiments made on, diflerent kinds of air, p. 2 1 3 — 229. Mr. Kirwan s account 
thereof approved by Dr. Pricftley, p. 230. Of the quantity of phlogifton in vitriolic 
air, p. 231. Method of purfuing that inquiry, ibid. Of the quantity of phlo- 
gifton in fulphur, p. 233. Of the quantity of ditto in marine acid air, p. 233. 
Table, (hewing the folubility or infolubility of, in alcohol, by Dr. Withering, 
P- 33 6 * 
Six, Mr. James. See Thermometer. 
Slag, or vitrified cinder. How produced, p. 31. 
Smeaton, John. See Collifion of llodies. 
Smelting honfes. The large furnaces ufed there prefent a molt ftriking refemblance of 
the eruption of a volcano, p. 5 f . 
Specific fire . See P blogifion. 
Specific gravity. See Saline Subjiances. 
Stones. Showers of, thought by the ancients to have been miraculous rains, uncovered 
to be volcanic, ii. Their being mixed with water accounted for, p. tv. 
Sulphur. See Inflammable Air, Saline Subjiances , Method of eftimating the quantity 
of fixed air produced during it combuftion, p. 233. All the attempts hitherto made 
to determine its conilituent parts evidently defective, p. 234. Its fpecifi- gravity 
when weighed in water by Mr. Kirwan, and in oil by Mr. Petit, p. 235. 
O 0 0 2 
Tables 
