142 



the force of gravity, the effect of such change, even at the 

 equator, must be regarded as entirely inadequate to those exten- 

 sive movements, and permanent changes of level, attending 

 earthquakes. 



Dr. Jackson thought, that if there were regular periods in the ris- 

 ing and subsiding of lavas, even though not corresponding in times 

 with tidal movements, it might possibly be imputed to attractions 

 of the heavenly bodies, as the theory of M. Perrey seemed lo re- 

 quire ; for if the operation of the attraction of the sun and moon 

 acted as a dynamical force sufficient to produce Earthquake phe- 

 nomena, by its influence on the liquid lava beneath the earth's 

 crust, it ought to be adequate to produce an outpouring of lavas 

 from the open vents of volcanoes, especially in those having 

 such very fluid lava as that of Kilauea. 



Dr. Jackson also remarked, that the gradual transportation of 

 earthy matters from elevated lands into the ocean bed, must, in a 

 more gradual, and, perhaps, imperceptible manner, continually 

 disturb the balance of our spheroid of revolution, requiring the 

 compensating force of elevatory movements to counteract this 

 disturbance of the equilibrium. That when the difference of 

 level had become sufficiently altered to be adequate to overcome 

 the resistance of the earth's crust, a paroxysmal elevation might 

 take place, and land be suddenly elevated, with all the pheno- 

 mena of an earthquake, as happened in Chili in 1834. 



Mr. Bouve, Dr. Jackson, and Prof. Rogers expressed the wish 

 that Mr. Stodder would bring his essay again before the Society, 

 that this subject might be more fully discussed. 



Dr. Bryant stated that he saw, the first of January, at 

 Cohasset, Mass., Sylvicola coronata, Yellow-crowned War- 

 bler, and S. parus, Hemlock Warbler. He had never 

 before seen them, in this region, later than the middle of 

 November. 



Dr. Phineas M. Crane, of East Boston, and Mr. Samuel 

 H. Scudder, of Boston, were chosen Resident Members. 



