160 Proceedings of the Royal Society 
The Journal of the Eoyal G-eographical Society. Vol. XXXII. 
Syo.— F rom the Society. 
Jahrbuch der kaiserlich-kbniglichen geologischen Keichs-Anstalt. 
1863. XIII. Band. 8vo. — From the Austrian Government. 
Memoires de I’Academie Imperiale des Sciences de St. Peters- 
bourg. VII® Serie. Tome IV., Xos. 10 et 11. Ito. — From 
the Academy. 
Bulletin de TAcademie Imperiale des Sciences de St. Petersbourg. 
Tome IV., Nos. 7-9. Tome V., Nos. 1 et 2. 4to. — From the 
Academy. 
Tables of Heights in Sind, the Punjab, North-western Provinces, 
and Central India, determined by the great Trigonometrical 
Survey of India, Trigonometrically and by Spirit-Levelling 
operations. 8YO.~~From the Director of the Survey. 
Monday^ 18th January 1864. 
His Grace the Duke of AHGYLL, President, in the Chair. 
The following Communications were read i™- 
1. Description of the Lithoscope, an instrument for dis- 
tinguishing Precious Stones and other bodies. By Sir 
David Brewster, K.H. 
The Instrument was exhibited. 
2. On the Temperature of certain Hot Springs in the Py- 
renees. By E. E. ScoBESBY- Jackson, M.D., F.E.C.P. 
In the year 1835, Principal Forbes very carefully observed the 
temperatures of certain springs in the Pyrenees, with the view 
of ascertaining to what extent changes of temperature occur in 
them. Observations previously made were, for several reasons, of 
uncertain worth, and Principal Forbes was desirous of then fixing 
data for future observers with a degree of accuracy hitherto un- 
attempt ed.’’ 
The author having determined to spend his autumn holidays in 
the Pyrenees, believed that a careful repetition of such observa- 
tions, after the lapse of twenty- eight years, would afford results of 
