Geological Society. 233 
Coefficient of 
Bee | mahon, | mmORBSputoniS han, | Semel | of emt 
1 136°77 140 170 — ett 
2 155-33 160 190 ii ere 
S| soso) sie | | 
5 was { been’ 180 a ay 
6 17492 | ed pe = te 
8 188-30 191 211 Sig ae 
ees 8) aug? gag (op eae 
v | 2602 1] 353 b79 es ue 
9" 279-42 | a aes — = 
13" Roeee boson? RG op a TE 
Hence it appears, that as the steam becomes more and more super- 
heated, the coefficient of expansion approaches that of a perfect gas. 
The authors hope that these experiments may be continued, and that 
the results obtained at greatly increased pressures will prove as 
important as those already arrived at. 
GEOLOGICAL SOCIETY. 
[Continued from p. 157.] 
December 5, 1860.—L. Horner, Esq., President, in the Chair. 
The following communication was read :— 
‘‘On the Structure of the North-west Highlands, and the Rela- 
tions of the Gneiss, Red Sandstone, and Quartzite of Sutherland and 
Ross-shire.”’ By Professor James Nicol, F.R.S.E., F.G.S. 
The author first referred to his paper in the Quart. Journ. Geol. 
Soc., vol. xii. pp. 17, &c., in which the order of the red sandstone 
on gneiss, and of quartzite and limestone on the sandstone, was 
established, and in which the relation of the eastern gneiss or mica- 
schist to the quartzite was stated to be somewhat obscure on account 
of the presence of intrusive rocks and other marks of disturbance. 
Having examined the country four times, with the view of settling 
some of the doubtful points in the sections, the author now offered 
the matured result of his observations. He agrees with Sir R. 
Murchison as far as the succession of the western gneiss, red sand- 
stone, quartzites (quartzite and fucoid-bed), and limestone is con- 
