386 Intelligence and Miscellaneous Articles. 



the northern extremity of the island to the 20th parallel of south 

 latitude. Beyond this granite and other primitive rocks occur as 

 far as lat. 22°, south of which the central parts of Madagascar are 

 practically unknown to Europeans. 



Some crater-lakes and numerous hot and mineral springs occur. 



Earthquakes are occasionally felt in the island, most frequently 

 in the months of September and October. The shocks are generally 

 slight. 



Only a single trap-dyke is known near Antananarivo. The hills 

 around this city are of varieties of granite (? granitoid gneiss). The 

 general direction of the strata is parallel to the long axis of the 

 island. 



Marine fossils have been found by Rev. J. Richardson and Mons. 

 Grandidier in the south-west part of the central plateau. These 

 fossils are referred by the last-named traveller to the Jurassic 

 system. Remains of Hippopotami, gigantic Tortoises, and an extinct 

 Ostrich-like bird have also been recorded. North and north-west 

 of the fossiliferous rocks, between them and the volcanic district of 

 Ankaratra, sandstone and slate occur. North of this volcanic 

 district again is a tract of country in which silver-lead (mixed with 

 zinc) and copper are found. 



Near tbe north-western edge of the central plateau are granitic 

 escarpments facing northwards and about 500 feet high. Some 

 details were also given of valleys through the central plateau and of 

 lagoons within the coral reefs on the coasts. To these remarks 

 succeeded some details of the physical features exhibited by the 

 province of Imerina as seen from Antananarivo. 



1 4. " Notes on some Cretaceous Lichenoporidge." By G. R. Yine, 

 Esq. Communicated by Prof. P. Martin Duncan, E.R.S., F.G.S. 



XLII. Intelligence and Miscellaneous Articles. 



THE INFEA-KED EMISSION-SPECTRA OF METALLIC VAPOURS. 

 BY H. BECQUEREL. 



T AST year I submitted to the Academie des Sciences a short 

 account of my first researches on the infra-red spectra emitted 

 by metallic vapours, till then unknown *. Since that time I have 

 investigated the subject still further by making use of a special 

 spectroscope, which shall be described in a future paper ; I will 

 simply mention here, that the method consists in throwing the 

 spectra, about to be examined, upon a suitable phosphorescent 

 substance, which has been previously rendered luminous, and in 

 observing the temporary excitation, which precedes extinction, under 

 the influence of the infra-red rays. The lines and bands of the 

 emission-spectra then appear brilliant, and can be examined with 

 the microscope. 



In experimenting on different phosphorescent substances, notably 



* Comptes Rendus, t. xcvii. p. 71. 



