884 INDEX. 
Di-Chroie Media and Mono-Chroic Media, 793. See SmytH 
(Professor PrAzz1). 
Dickson (J. Douctas Hamiuton). On a Class of Determi- 
nants, 625. 
—— Least Roots of Equations, 119. 
Diethyl-Thetine, 585. See Lurts (Dr E. A.). 
Di-Isobutyl Thetine, 588. See Lerrs (Dr E. A.). 
Dimethyl-Thetine and its Derivatives, 571, 591, 597, 598, 
601-607. See Brown (Professor Crum) and Letts 
(Dr E. A.). 
Dipropyl-Thetine, 586. See Luvrs (Dr E. A.). 
Dises intended to Roll upon each other. By EpwarD Sane, 
191. 
Disruptive Discharge of Electricity. By ALEXANDER Mac- 
FARLANE, M.A., 633, 679. 
Dynamic Frame of a Machine, 6, 11, 13, 29, 31, 34. See 
JENKIN (Professor FLEEMING). 
E 
Eisenstein’s Continued Fractions. By THomas Murr, M.A., 
135. 
Electricity. On the Disruptive Discharge of Electricity. By 
ALEXANDER MACFARLANE, M.A., 633, 679. 
Electric and Thermal Conductivity. By Professor Tart, 717. 
Equations. Equation Vede=0, Qe representing a Linear 
Vector Function. By Gustav Piarr. Part I., 45, and 
Part II., 83. Alphabetical Index to the Notations in 
the Paper on Vege =0, 90. 
— Least Roots of Equations. By J. Doucnas Haminron 
Dickson, B.A., Fellow and Tutor of St Peter’s College, 
Cambridge, 119. 
Ethyl-Thetine, 583-584. See Lerrs (Dr E. A.). 
Ewine (J. A.) and Professor Frermina JENKIN. On the 
Harmonic Analysis of certain Vowel Sounds, 745-777. 
—— On the Application of Graphic Methods to the Deter- 
mination of the Efficacy of Machinery, Appendix to 
Part I1., 711. 
F 
Felspars, Part I., being Chapter Second on the Mineralogy 
of Scotland, 197. See HeppLeE (Professor F. M.). 
G 
Garnets. Chapter Third of the Mineralogy of Scotland. By 
Professor HEppiE, 299. 
Gases. Their Electric Strength, 643. 
Gauss’s Formula for Electro-magnetic Work. Determination 
of the value of m from the Number of Linkings, 180, 
186. See Tart (Professor P. G.). 
GBIKIE (Professor A.) On the Old Red Sandstone of West- 
ern Europe, 345. Part I.—Historical Introduction, 345. 
Condition of Western Europe previous to Old Red 
Sandstone Times, 350. The Lower Old Red Sandstone. 
The Basins of Deposit in the British Area, 353. Lake 
Orcadie—(1) Area of the Region, 355 ; (2) Work of pre- 
vious Observers, 357 ; (3) Description of different Dis- 
tricts :—(A) Caithness and Sutherland, 368. Order of 
Succession among the Strata, 374. Basement Conglo- 
merate, 375. Braemore and Ousedale Sandstones, 377. 


Section of Ben Griam Bheag, 382. Wick and Lybster 
Flagstones, 387. Their Paleontological Features, 388. 
Unconformable Junction of Old Red Sandstone at 
Portskerry, 396. Coast section from Dunnet Head to 
Duncansby Head. Paleontological distinctions of the 
Thurso Flagstone Group, 401. Gill’s Bay Red Sand- 
stone, 402. Huna and John o’ Groat’s Red Sandstones 
and Flagstones, 404. (B) The Orkney Islands, 406. 
Their Geological Structure and Sections, 408. Position 
and Order of Succession among their Strata,409. Their 
Fossils, 411. Origin of some Features of Orkney Scenery, 
413. (C) The Shetland Islands, 414. Geological Strue- 
ture of their Old Red Sandstone Area, 415. Their Petro- 
graphical Characters and Order of Succession among 
the Strata, 416. Their Fossils, 417. Their Volcanic 
Rocks, 418. Papa Stour, 419. (D) Basin of the Northern 
_Firths. Their Outliers, 422. The South Coast of Loch 
Orcadie from Buckie to the Spey, 433. From the Spey 
to the Nairn, 437. From the Nairn to Inverness, 441. 
From Loch Ness to Sutherlandshire, 443. Horizon of 
the Lower Old Red Sandstone in the Basin of the 
Northern Firths, 446. Volcanic Rocks of Shetland, 449. 
Table showing Vertical Range of Fossils of Old Red 
Sandstone of Caithness, 451. 
German Silver. Its Thermal and Electric Conductivity, 738. 
See Tart (Professor). 
Graphic Methods for the Determination of the Efficiency of 
Machinery, 1. See Jeyxry (Professor FLEEMING). 
Graphitoid. The Preparation and Properties of Pure Graphi- 
toid and Adamantine Boron. By Dr R. M. Morrison 
and R. SypNgEy Marspen, B.Sc., 689. 
H 
Hannay (J. B.). On a Method of Determining the Co- 
hesion of Liquids, 697. 
Harmonic Analysis of certain Vowel Sounds. By Professor 
FLEEMING JENKIN and J. A. Ewrne, B.Sc., 745-777. 
HEDDLE (Professor M. Forster). Chapters on the Miner- 
alogy of Scotland— 
Chapter Second.—The Felspars, Part I., 197. Determina- 
tion of the Water, 197. Determination of the Silica 
and the Bases, 197. Estimation of the Ferrous Oxide, 
198. Determination of Alkalies, 199. A Continuous 
High Heat converts Soluble into Insoluble Silica, 202, 
Overheating during Granulation largely increases the 
amount of Insoluble Silica, 202. Correct Analyses of 
Silicates cannot be executed unless Vessels of a Material 
other than Glass are employed, 205. Orthoclase from 
Intrusion Veins—Dykes, 209. From Dykes in Horn- 
blendic Gneiss, 209. From Dykes in Mica Slate, 210. 
From Dykes in Talcose Slate, 211. Orthoclase of 
Porphyritic Dykes, 214. Orthoclase from Exfiltration 
Veins in Granite, 215. From Exfiltration Veins in 
Syenitic Granite, 215. From Syenite, 218. From 
Micaceous Gneiss, 218. From Primitive Limestone— 
Necronite, 221. From Pitchstone Porphyry, 222. 
From Interbedded Porphyry, 223. From Trap Tufa, 
223. The Structural Appearances, 224, 225. What 
proportion of the Crystal does Intruded or Extruded 

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