C 5 2 3 3 
Mural Quadrant , defcrlption of that inventdd by Mr. Flamfteed 1689, p. $. Improve* 
meats in, by Mr. Graham, p. 10. 
Mufcles, the laws that govern the mufcles have the fame influence on the retina of the 
eye, p. 324. 
N. 
Nab, John M c , Experiments at Henley-Houfe, HudfonVBay, relating to freezing 
mixtures, p. 241. 
Naples* ill built, and in great danger from (hocks of earthquakes, p. 266. 
Nautilus , defcripdon of a newly difcovered Britiih (hell belonging to that family, called 
the frelh-water Nautilus, p. 1 60. 
Newton , Sir Ifaac , the utility of finding fluents by conflru&ion, manifefi to him* 
p. 441. 
Nickel, magnetical experiments on, p. 63. 
Nitre, Acid of, \ experiments refpe&ing freezing, with the common and dephlogifticated, 
air, p. 247. 
Nitre, Spirit of, experiments of a freezing mixture by the addition of fnow, p. 242* 
Experiments of oil of vitriol, p. 269. 
O. 
Ocular SpeBra of Light and Colours, new experiments on, p. 313. Four kinds of, 
ibid. 
Optic Pencils, See Eye, 
P. 
Palmar ole, IJlandof account of, p.376. 
Paralyfis , temporary ones generally fucceed to continued irritations and violent exertions, 
p. 332. 
Patella , defcription of a newly difcovered Brltifh (hell, called the oblong freih-water 
Patella, p. 168. 
Paterfon , William , account of a new ele&rical filh, p. 382. 
Phofphoric Hepatic Air, account of, p. 130. 
Piaggi * Father Antonio , a (Tilts Sir William Hamilton in keeping a journal of the opera* 
tions of Mount Vefuvius, p. 366. 
PctrefaBion , conje&ures relative to thofe found in St. Peter’s Mountain, near Maeltrichf, 
p. 443. Not the bones of crocodiles as at firfl fuppofed, ibid. Suppoled to belong 
to a Phyfeter or Breathing-fifli, Delphinus or Orca, p. 445. Thofe found near 
Whitby in Yorkshire, and fuppofed to belong to a Crocodile, prove to be the 
Vol. LXXVI. Yy y Ikeleton 
