[ «93 3 
Salt-water, Some relief obtained by it in the cure of a violent eruption on the face, 
neck, and breatt, p. 34. 
Sand. A progreflive induration of mattes of, at the bottom of the ocean, p. 37. 
Selenite. Comparifon of the Montmartre platter ftone, with feveral felenitical fub- 
fiances, p. 16. 
Sheep. Dubious whether there are any Free-martins among, p. 287. 
Shirl frequently, though erroneoufly, called bafaltes, p. 24. Contains neatly as much 
earth of allum as the Cornifii porcellane clay, ibid. Sal catharticus amarus obtained 
from pumice fione and fhirl, ibid. 
Silver. Experiments on the ore called argentum vitreum, p. $32. Concluftve expe- 
riment to ttaew that vitreous filver ore is a compound of filver and fulphur,— and 
that, when pure, it contains between ninety-two and ninety-three grains of filver 
in one hundred, p. 536. 
Sitodium incifum & Macrocarpon f or bread-fruit, defcribed, p. 462. Lift of authors who have 
given an account of it, p. 462. The plants and feeds of, how preferved in a voyage 
from Ceylan to Europe, p. 463. Generic defcription of it, p. 464. Specific defcription 
of the Sitodium incifum, p. 470. Obfervations on the Macrocarpon, p. 471. Va- 
rious ufes of its parts, p.471. Defcription of the various diihes made of thefe 
fruits by the Dutch, p. 476. 
Slate, Irifh, replete with allum, p. 23. 
Spar . Change of cryftal into felenitical, p. 12. The felenitical, orgypfeous fpars, confilt 
of acid of vitriol, calcareous earth, and fome clayey matter, p. 14. Some among 
thefe enumerated, which were not before taken for felenitical fpars, ibid. No ful- 
phur in femitranfparent Auvergne fpar, p. 13. Experiments on thefe compared 
with the common Montmartre fione, p. 16. Calcareous earth in the gypfum, 
fhewn to contain more acid of vitriol than that in the felenitical fpars, p. 17. 
Change of clay into Feld-fpar, and different gradations of the change, p. 22. Allum 
made cff feld-fpar, p. 23. And of the Labradore fione, ibid. Account of fub- 
fiances which have a fparry appearance, and how to diftinguifh them from 
fpars, p. 27. Phofphoric fpar, cryfiallized, forms perfect cubes, p. 28. One ex* 
ception only to this rule, ibid. Of a fet of fpars whofe properties were not hitherto 
known, and experiments made on one oT them, p. 29. Probable that the green 
and yellow glimmers from johngeorgenttadt may be of this kind, p. 30. 
Stars, Account of an occultation of 1 c* cancri, by the moon, p, 163. Account of 
occultations of feveral, p. 178. 
Stone. Confolidated by cementing cryftalline particles, p. 8. A formation of it to 
this very day, in certain places, more perfect than is imagined, p. 38. Portland- 
fione confiderably hardened by being wafhed with water impregnated with rutty iron, 
p. 44. Stones and marbles continually forming in the earth, and the confolidation 
of them effected by means of water and vapour, and the induration of many of 
Vol. LXIX. 4 X theft 
