28 INDEX. 



O/V of Amflower feeds, account of, Vol. T. p 234 — effiy on it, 235. 



— (Cajhr) recommended to Americans, Vol. 1. p. 239. 



— of benni-feed, account of, Vol. I. appendix p. 239 — equal to Florence 



oil, ib. 

 Oils, fiom whatever vegetables, if obtained by expreffion, agree in their 



general qualities, Vol. I. p. 238. 

 Ol.bombaf. [oil of cotton feedj how obtained, Vol. I. p. 235 medicinal in 



the cholic, ib. 

 OJivtr (Jindreiu) his theory of lightning and thunder as oppofed to Dr. 



Franklin's, Vol. II. p. 74 — his theory of water-fpouts. Vol. II, p. 



101. 



Opium, obfervations on. Vol IV. p. 388 — how and where obtained, 389 — 

 its component parts, 390, 394 — compared with that extrafted from 

 garden lettuce, and various experiments made on both, 392 to 410 — 

 mode of extrafting the latter, 411. 



Optics, a deception in, explained. Vol. If. p. 37. 



Oplical problem, by Francis Hopkinfon, Vol. II. p. 201 — and folved by 

 Mr. Rittcnhoufe, 202. 



Orloftheenr.h, its eccentricity and diftance from the fun. Vol. I. p. 103. 



0;vj- and minerals, variety of, in America, Vol. I. pref. p. xiii. 



Or?rt«.r of generation in plants alferted. Vol. III. p. 203. 



Orthogi\ipljy and orthoepy, how to fix them. Vol. HI. p. 262 — imperfeftion 

 of the former, 268 — farther obfervations on orthography, 271 — advan- 

 tages of a new one, 272. 



Orrery, defcription of a new one invented by Mr. Rittenhoufe, Vol. I. p. i. 



Otio (Dr.) his account of an oil drawn from lunflower feeds. Vol. I. p. 234. 



(Monf.) on the difcovery of America, Vol. It. p. 263. 



OverfJtiiig oi{}[i\^s, a preventive againft. Vol. II. p. 302. 



Oivls venerated by certain nations, Vol. IV. p. 206. 



Oxyds containing oxygen. Vol. IV. p. 458. 



Oxynen, or dephlogifticated air, abforbed in the phlogiftication of air, Vol. 

 IV. p. 1 — obfervations on it, ib. to p. n — in what oxyds contained. 

 Vol IV. p. 458 — combined with azote produces the nitric acid, 472. 



gns, or pure refpirable air, what proportion of it in the atmofphere. 



Vol. IV. p. 128, 417 — how to promote a fupply of it, ib. p. 141 — 

 mercury precipitated from it, 416 — a principal ingredient in marfh air, 

 427. 



O^/lerJL/l bids ({oS)\) in the Atlantic dates. Vol. IV. p. 439. 



-^hel/j of prodigious fize .and vaft quantities in the Mobile country. Vol. 



III. p. 218 — ufed in compounding Indian earthen ware, ib. 



Pag! (jfnhn) his defcription of a meteor feen in Virginia, Vol. II. p. 173 — 

 letter to him from Dr. Rittenhoufe, with remarks on that meteor, 175. 

 Paints (valuable) Vol. I. pref, p. xii. 



Vol. I. p. 256. 



Pais de Vaud, proportion of deaths there, Vol. III. p. 41. 



Papavtr 



