INDEX. 51 7 
Small-pox , the dreadful ravages of that diftemper, in 
Warrington, p. 439. 
Smcak, a conductor of eledricity, p. 392 — 397. 
Snails , an account of the revivifcence of fome that had 
been many years in a continued Hate of torpidity, 
p. 432, &c. 
Solar fpots difcovered by Galileo, p. 2. Diligently ob- 
ferved by Scheiner and Hevelius, p. 3. Nothing of 
moment derived from their obfervations, except the 
rotation of the Sun upon its axis, and the inclination 
of that axis to the plane of the ecliptic, ibid. A fpoc 
of extraordinary fize, feen Nov. 1769, p. 6. Alte- 
rations of its figure, p. 7. Probably a vaft excava- 
tion in the luminous matter of the Sun, p. 8. Its 
various appearances accounted for, ibid. Its return, 
p. 9. Its nucleus confiderably beneath the level of 
the Sun’s fpherical furface, p. 10. Means ufed to efti- 
mate its depth, ibid. The like alterations obferved 
in other fpots, p. 12. Diftance within the limb at 
which the contraction of the umbra ufually takes place, 
ibid. Changes effcded in fome fpots by the neighbour- 
hood of others, p. 13. Queries and conjedures con- 
cerning the fpots, p. 20. Time of the appearance 
fhorter than the time of the occultation, p. 26. Mr. 
Marfhall’s obfervations of the fpots, p. 194. Mr. 
Wooiafton’s ditto, p. 337. 
Sen or Sun-plant of Hindolian, its culture and ufes, p. 100. 
Spark , eledric, experiments on colour of, when drawn 
'through wood, p. 419. 
Spica virginis , occultation of, by the Mcon, obferved at 
Pekin, p. 42. 
Sproule y enfign George, his obfervations of the immer- 
fions and emerfions of Jupiter’s fatellites, p. 180. 
Steblin , M. de, his defeription of a mafs of raw or native 
iron, found in Siberia, p. 462. 
Stomachy its formation and ufes in different animals, 
p. 312, 313. That of the Gillaroo trout defended, 
p. 1 2 1. Singularities in its ftrudure, p. 123. 
St ones 
