CONTENTS. 
Yll 
Account of the Asafcetida Plants ( Narthex Asafcetida, Falconer) 
which have recently flowered and fruited in the Edinburgh Bo- 
tanic Garden. By Professor Balfour, .... 337 
On the Composition of the Glassy Surface of some Vitrified Forts. 
By Thomas Bloxam, F.C.S., Assistant Chemist to the Industrial 
Museum of Scotland, ...... 338 
On the Reduction of Observations of Underground Temperature, 
with Applications to Professor Forbes’ Edinburgh Observations 
and the Continued Calton Hill Series. By Professor William 
Thomson, Glasgow. ...... 342 
On the Method of Reducing Observations of Underground Tempera- 
tures, with its Application to the Monthly Mean Temperatures, &c. 
By Professor Everett, ..... 346 
Opening Address, Session 1860-61. By his Grace the Duke of 
Argyle, ....... 350 
Contributions to the Natural History of Volcanic Phenomena and 
Products in Iceland. By W. Lauder Lindsay, M.D., F.L.S. 
Communicated by Professor Balfour, .... 387 
On the Pediculi infecting the Different Races of Man. By Andrew 
Murray, ....... 389 
Note on Hydrated Sulphuric Acid. By Dr Lyon Playfair, C.B., . 390 
Note respecting Ampere’s Experiment for showing the Repulsion 
of a Rectilinear Electrical Current on itself. By Principal 
Forbes, LL.D., &c., ...... 391 
Fragmentary Notes on the Generative Organs of some Cartila- 
ginous Fishes. By John Davy, M.D., F.R.SS. Lond. and Edin., 392 
On a Method of taking Vapour Densities at Low Temperatures. 
By Dr Lyon Playfair, C.B., F.R.S., and J. A. Wanklyn, 
F.R.S.E., . . . . . . .395 
Memoir of Sir Thomas Makdougall Brisbane. By Alexander 
Bryson, ....... 398 
Notes on the Snow Crystals observed during the late Frost. By 
Professor Allman, ...... 399 
The Bifilar Magnetometer ; its Errors and Corrections. By John 
Allan Broun, F.R.S., Director of the Trevandrum Observatory. 
Communicated by Professor Tait, .... 406 
On the Horizontal Force of the Earth’s Magnetism. By John 
Allan Broun, F.R.S., Director of the Observatory of the Rajah 
of Travancore. Communicated by Professor Tait, . . 407 
Notice of an Instrument intended for the Measurement of Small 
Variations of Gravity. By John Allan Broun. Communicated 
by Professor Tait, . . . . . .411 
On the Law of Growth in Woody Circles of Exogenous Trees, as 
indicated by the examination of a single specimen. By Principal 
Forbes, ....... 412 
On the Embryology of Asteracanthion violaceus (Linn. sp.). By 
Wyville Thomson, M.R.I.A., F.G.S.,.&c., Professor of Natural 
History in Queen’s College, Belfast, . . . .413 
Some Observations on the Albino. By John Davy, F.R.SS. L. & 
E., &c., . . . . . .416 
