[ 5*9 ] 
or Orca, p, 44^. Thofe found near Whitby in Yorkffiire prove to be the fkeletonof 
a Balsena, p. 445. 
D. 
Damp Beds and Rooms , the caufe of the danger of them, p. 298. 
Darwin , Robert Waring , new experiments on the ocular fpedtra of light and colours, p. 3 13. 
Devils , ilory of Benvenuto Cellini feeing them run on the tops of houfes at Rome, 
p. 319. 
Diachylum , experiments on, with fea fait and fpirit of wine, p. 156. Experiments on, 
with Glauber fait and fal foda?, p. 158. 
Dividing of Inflruments , improvements in, p. 8. Further improvements by Mr. Bird, 
p. 13. Ocher improvements propofed, ibid. More improvements by Mr. Ramfden, 
p. 17. Explanation of Mr. Hindley’s improvement, p. 19. An inch capable of being 
divided into 60,000 parts, p. 24. Propofed improvements by Mr. Smeaton, p. 31. 
E. 
Earthquakes, reafons for fuppoling the earthquakes at Calabria and at Medina to have 
been occasioned by a volcanic eruption at the bottom of the fea, p. 380. 
Elettrical Fijh, account of a new one, p. 382. 
Elliot , 'John , Obfervations on the Affinities of Subdances in Spirit of Wine, p. 133* 
Eider , Profejfor , made ufe of approximations in refolving problems, p. 93. 
Eye , the retina proved to condil of fibres, p. 316. Retina and mufcles governed by 
fimilar laws, ibid. Perfons fometimes fuppofe defeats in their eyes only from 
observing fpedlra, p. 318. Danger of infpedting very luminous objedls too long a 
time, p. 332. Invefiigation of the caufe of that indiftindtnefs which has been 
aferibed to the fmallnefs of the optic pencil, p. 500. Experiments with the naked 
eye, p, 501. Microfcopic experiments with the eye, p. 5,02* 
F. 
Elamjleed \ Mr . defcription of the fextant invented by him, p. 3. Defcription of his 
mural arc, p. 5. 
Fluents , a new method of finding them by continuation, p. 432. Its utility manifefi to 
Sir Ifaac Newton, p.441. 
Freezing Mixtures % experiments at Henley-Houfe,. HudfonVBay, relative to, p. 241* 
Experiments with fpirit of nitre and fnow, p. 242. Experiments on the common and 
dephlogidicated acids of- nitre, p. 247. Experiments on the phenomena obferved on 
mixing fnow with thefe acids, p. 234. Experiments on the vitriolic acid, p. 263^ 
Experiments on the mixture of oil of vitriol and fpirit of nitre, p, 269. Experi- 
ments on the fpirit of wine, p. 269, 
G. 
