380 
GENERAL INDEX. 
♦Signals, recording the movements of 
points and, W. Smith on a means of, 
1875, 252 
Silesia, Upper, Prof. F. Roemer on a 
fossil spider lately discovered in the 
Coal-Measures of, 1865, 73 
♦Silica cells, artificial, experiments on 
the formation and growth of, by Prof. 
Cohn, 1876, 146 
- in an igneous rock, an accurate and, 
rapid method of estimating the , J. H. 
Player on, 1886, 471 
-various kinds of, and artificial stone, 
Rev. H. Highton on, 1870, 60 
♦Silicates, aluminous, Dr. Sullivan on the 
precipitation of, from solution, 1864, 42 
♦-constitution of some, Prof. Scha- 
farik on the, 1873, 66 
-formation of, through sublimation, 
G. vom Rath on a remarkable block of 
lava ejected by Vesuvius at the great 
eruption of April 1872, which proves 
the, 1872, 120 
-the natural, the chemistry of, Prof. 
T. Sterry Hunt on, 1884, 679 
-- some natural, the chemical structure 
of, F. W. Clarke on, 1887, 650 
Silicified forest, Prof. H. A. Nicholson on 
a, in the Rocky Mountains, with an 
account of a supposed fossil chip, 1872, 
192 
- wood from the Rocky Mountains, 
Prof. H. A. Nicholson and W. H. Ellis 
on a remarkable fragment of, 1874, 88 
Silicious organic remains in the lacus¬ 
trine deposits of the province of Nova 
Scotia, Canada, a preliminary examina¬ 
tion of the, by A. H. Mackay, 1884, 742 
-sandstones, the cementation of, Rev. 
A. Irving on, 1883, 504 
——■ skeletons, the replacement of, by 
carbonate of lime, W. J. Sollas on, 1879, 
350 
-and other hot springs in the volcanic 
district of the North Island of New 
Zealand, W. Lant Carpenter on, 1881, 
580 
Silicon in cast iron, T. Turner on, 1886, 
595 
-the influence of, on the properties 
of iron and steel, T. Turner on, 1886, 
597 
-- the influence of, on the properties 
of steel, report on, 1887, 43 ; 1888, 69 ; 
1889, 267 ; 1890, 262 
-compounds, W. B. Hart on some 
organo-, 1887, 661 
— —compounds, some new, Prof. J. E. 
Reynolds on, 1888, 640 
—— and iron, alloys of, R. A. Had field 
on, 1889, 267 
♦Silk industry, the, T. Wardle on some 
important statistics relating to, 1887, 
852 
♦Silkworm, Mrs. B. Neill on the acclima¬ 
tisation of the, 1875, 218 
-the secretion of silk by the, Prof. G. 
Gilson on, 1889, 628 
* - and moth, the Muga (Anthercea 
assama), of Assam, and other Indian 
silk-producing species, T. Wardle on, 
1887, 770 
♦Sillar (W. C.) on the utilisation of 
sewage, 1876, 68 
Siluria, Rev. W. S. Symonds on some 
ancient drifts and old river beds of, 
1865, 74 
Silurian in north-east Montgomeryshire, 
the strata forming the base of the, J. 
B. Morgan on, 1890, 816 
-lower felsites, the, of the south-east 
of Ireland, Dr. F. H. Hatch on, 1889, 568 
-formations of the centre of Belgium, 
Prof. C. Malaise on the, 1870, 78 
* -rocks of Ireland, W. H. Baily on the 
fossils of the, 1861, 108 
- rocks of the Isle of Man, Prof. 
Harkness and H. Nicholson on the, 
1865, 58 
-rocks of the south-east of Cumber¬ 
land and the north-east of Westmore¬ 
land, Prof. Harkness on the Lower, 
1864, 53 
- rocks and fossils of Dudley, C. 
Ketley on the, 1865, 63 
-rocks, spheroidal structure in, Rev. 
J. D. La Touche on, 1869, 95 
-rocks of the counties of Roxburgh 
and Selkirk, C. Lapworth and J. Wilson 
on the, 1871, 103 
-rocks of the south of Scotland, D. 
J. Brown on the, 1871, 93 
-rocks, Upper, of the Pentland Hills 
and Lesmahago, D. J. Brown on the, 
1871, 93 
--rocks, Prof. J. Hall on the relations 
of the Middle and Upper, of the United 
States, 1872, 103 
-rocks, H. Hicks on the Cambrian 
and, of Ramsey Island, St. David’s, 
1872, 107 
-rocks, H. Hicks on some areas where 
the Cambrian and, occur as conform¬ 
able series, 1875, 69 
* -rocks in Teesdale, the finding of, 
VV. Gunn on, 1877, 71 
-rocks of North Wales, Prof. T. McK. 
Hughes on the, 1886, 663 
-rocks, Upper, of Lesmahagow, Dr. 
R. Slimon on the, 1876, 96 
* -rocks, of Ohio, E. W. Claypole on 
a fossil tree from the Upper, 1879, 343 
* -rocks in Roxburgh and Dumfries¬ 
shire, C. Lapworth on the discovery of 
Upper, 1870, 78 
-schist, Dr. R. N. Rubidge on the re¬ 
lations of the, -with the quartzose rocks 
of S. Africa, 1864, 66 
