364 



was only occasionally broken by the lightning, which flashed in every 

 direction, while the air was rent with loud and reiterated explosions 

 like the discharges of artillery, which accompanied each eruption of 

 volcanic matter, and conspired to strike the deepest terror, and to 

 spread among the inhabitants a universal panic that the day of judge- 

 ment was arrived. On the 24th the atmosphere became clearer, and 

 the houses were found covered to the depth of eight inches with ashes, 

 in which many small birds were found suffocated. Deer and other 

 wild animals flew to the town for refuge, and the banks of the neigh- 

 bouring streams were strewed with dead fish. In Segovia, and as 

 far as eight leagues from the volcano, the showers of black sand were 

 so abundant as to destroy thousands of cattle ■ and many were 

 subsequently found whose bodies exhibited one mass of scorched 

 flesh. 



Within the Bay of Fonseca, and two miles from the volcano, it is 

 stated that two islands, from two to three hundred yards in diameter, 

 were thrown up, probably from the deposit of masses of scoriae on 

 previously existing shoals. 



It was resolved unanimously : — " That the thanks of this Society 

 be given to their Secretary Peter Mark Roget, Doctor of Medicine, 

 for the zeal and ability which he has uniformly displayed, and the 

 many valuable services he has rendered in promoting its objects." 



January 14, 1836. 



FRANCIS BA1LY, Esq., V.P., and Treasurer in the Chair. 



Dr. Daubeny's paper entitled, " On the action of Light upon 

 Plants, and of Plants upon the Atmosphere," was resumed and con- 

 cluded. 



The objects of the experimental inquiries of which the author gives 

 an account in this paper were, in the first place, to ascertain the ex- 

 tent of the influence of solar light in causing the leaves of plants to 

 emit oxygen gas, and to decompose carbonic acid, when the plants 

 were either immersed in water, or surrounded by atmospheric air. 

 The plants subjected to the former mode of trial were Brassica 

 oleracea, Salicornia herbacea, Fucus digitatus, Tussilago hybrida, Co- 

 chlearia armorica, Mentha viridis, Rheum rhaponticum, Allium ur- 

 sinum, and several species of Graminecz. Geraniums were the only 

 plants subjected to experiment while surrounded with atmospheric 

 air. Comparative trials were made of the action on these plants of 

 various kinds of coloured light, transmitted through tinted glass, of 

 which the relative calorific, illuminating, and chemical powers had 

 been previously ascertained ; and the results of all the experiments 

 are recorded in tables; but no general conclusion is deduced from 

 them by the author. He next describes a few experiments which 

 he made on beans, with a view to ascertain the influence of light on 

 the secretion of the green matter of the leaves, or rather to deter- 



