1824.] Submarine Forest in the Frith of Tay. 295 



it, by deposition from the sea, and the washing down of earth 

 from the land ; that it has emerged from this great depth till a 

 part of it has become dry land ; but that it is now sinking 

 again, if the tradition of the country deserves any credit ; that 

 the part of it in the sea is deeper under water at present than 

 it was a few years ago." Illustrations of the Huttonian Theory, 

 p. 453. 



A careful examination of these conjectures, which had been 

 offered to account for the phenomena of submarine forests, soon 

 convinced me that the subject was still imperfectly understood. 

 Under this impression, I endeavoured to become possessed of 

 all the conditions of the problem,'.-<and now venture to offer a 

 solution. The opinion which I havif, been led to form has been 

 entertained for some years, and stated to several friends, with- 

 out an objection having presented itself. 



If we suppose a lake situate near the sea-shore, and having 

 its outlet elevated a few feet above the rise of the tide, we 

 have the first condition requisite for the production of a sub- 

 marine forest. 



If we now suppose, that, by means of mud carried in by 

 rivulets, and the growth of aquatic plants, this lake has become 

 a marsh, and a stratum of vegetable matter formed on the 

 surface, of sufficient density to support trees, we arrive at the 

 second condition which is requisite. This state of a marsh, 

 formerly a lake, is of common occurrence, more especially 

 where the surrounding grounds are high, and covered with soii, 

 for in this case the rain washes down earthy particles, and, by 

 spreading them on the grassy surface, renders it a more suitable 

 soil for the growth of trees. 



In this second condition, all the strata below the outlet of 

 the marsh are kept constantly wet, or in a semifluid state. The 

 force of ordinary subsidence, aided by occasional earthquakes, 

 may render the whole tolerably compact ; yet the quantity of 

 water necessarily present, will prevent any thing like the degree 

 of condensation of ordinary alluvial land or soil from taking 

 place. 



Suppose a marsh in this condition to have the level of its 

 outlet lowered, or rather, to have its seaward barrier removed 

 (an occurrence which many circumstances induce us to believe 

 to have happened frequently both on the east and west coasts 

 of this country, where submarine forests are not of rare occur- 

 rence), what consequences would follow t The extremities of 

 the strata now exposed to the sea, would at every ebb-tide be 

 left dry, to a depth equal to the fall of the tide. Much water, 

 formerly prevented from escaping by the altitude of the outlet, 

 would now ooze out from the moist beds, and the subsiding 

 force would act more powerfully in the absence of the water 

 which filled every pore. All the strata above low water-mark 



