330 
POPULAR SCIENCE REVIEW. 
F.R.S., discusses the completely reduced observations, from 1837 to 1869 
inclusive, of the four great earth-thermometers sunk into the rock of the 
Calton Hill, at the Royal Observatory, Edinburgh, by the late Principal 
Forbes, pursuant to a vote by the British Association for the Advancement 
of Science. Leaving on one side the several natural-philosophy data which 
have been investigated from smaller portions of the same series of observa- 
tions both by Principal Forbes and Sir William Thomson, the author applies 
himself solely to trace the existence of other cycles than the ordinary annual 
one in the rise and fall of the different thermometers. Of such cycles, and 
of more than one year’s duration, he considers that he has discovered three ; 
and of these the most marked has a period of 11 T years, or practically the 
same as Schwabe’s numbers for new groups of solar spots. Several 
numerical circumstances, however, which the author details, show that the 
sun-spots cannot be the actual cause of the observed waves of terrestrial 
temperature, and he suggests what may be ; concluding with two examples 
of the practical use to which a knowledge of the temperature cycles as 
observed may at once be turned, no matter to what cosmical origin their 
existence may be owing. 
Fluids in Crystals. — Spectrum analysis, lays the Chemical Neivs , has been 
applied by Vogelsang and Geissler to the difficult question of determining 
the chemical nature of the fluid found enclosed, in minute quantity, in the 
cavities of certain quartz-crystals. Fragments of quartz were placed in a 
small retort which was connected with an air-pump and exhausted ; then, 
by the application of heat, the quartz decrepitated, and the evolved vapour 
was examined in a Geissler-tube. The presence of carbonic acid was thus 
abundantly proved, and this was confirmed by the turbidity which it pro- 
duced in lime-water. 
The late Professor Lame and Professor Magnus. — During the past quarter 
we have lost two great luminaries of the natural-philosophy world. Professor 
Lam6 was a member of the Institute since 1843. He was a very 
celebrated physicist and mathematician, was bom in 1795, educated at 
the icole Polytechnique, and was for some time engineer in the Russian 
service. On his return to France he was appointed Professor of Physics at 
the above-named school, and remained in that capacity until the year 1845, 
when he was elected Examiner of the school. In the year 1848 he was 
appointed Professor of the Faculty of Sciences at Paris. Among his very 
many published works, those on mathematics and on the elasticity of bodies 
are the most celebrated. — Dr. Heinrich Gustav Magnus, of Berlin, died 
there on the 4th inst. He was born at Berlin on the 2nd of May, 1802, and 
took the degree of Ph.D. at Berlin University in 1827, his inaugural disser- 
tation written in Latin bearing the title “ De Tellurio.” In 1834 he was 
appointed Extraordinary Professor of Natural Philosophy at Berlin Univer- 
sity, and in 1845 became Ordinary Professor for the same subject. He 
largely contributed to extend our knowledge of physical sciences, but, 
owing to the great mass of his various contributions, it is quite impos- 
sible to give here even a brief outline of his labours. Professor Magnus was 
a member of several scientific societies and institutions, and carried on a 
regular correspondence with the foremost scientific men in the civilised 
world. 
