CHANGES IN DIKED MARSHES. 239 



proximity to each other : for instance, a patch of samphire 

 {Salicornia herbacea) in the midst of a luxuriant spontaneous 

 growth of vahiable fresh-meadow grasses. This unsatisfactory 

 condition was assumed to be due to a still inefficient mode of 

 drainage, aggravated liere and there by locally confined imper- 

 vious layers of a clayish nature within the succeeding stratifi- 

 cations of the soil. Knowing from personal observation 

 elsewhere that the fitness, even of the best of soils once 

 thoroughly impregnated with salt water, for a successful cul- 

 tivation of most farm crops, would largely depend on the 

 degree of drainage which that soil chanced to enjoy after the 

 excess of the salt water had been prevented, I have continued 

 to inquire, for two succeeding seasons, by means of chemical 

 analyses, into the degree of the changes w^iich the subsoil 

 water undergoes in consequence of a gradual replacement of 

 the saline oceanic water by the fresh water of the creek, which 

 flows through the marshes. 



As intervening impervious strata of soil would quite natu- 

 rally retard for years the removal of the accumulated saline 

 .matter of the surface-soil by means of atmospheric precipitations 

 of moisture, it became of the utmost importance to ascertain 

 the peculiar character of the various successive layers of soil, 

 which exist within the different parts of the marsh lands, as 

 far as their quality and their extent are concerned. The 

 chances of srettins: some more definite information reo;arding 

 these points have been somewhat improved during the past 

 years, in consequence of a more extensive and thorough con- 

 struction of drain ditches within the central part of the marsh 

 lands. 



Within the few succeeding pages, I propose to report my 

 analytical results, and to discuss shortly : first, the late changes 

 in the composition of the subsoil water, as compared with the 

 previous years ; second, the quality of the soil in the central 

 portion of the marshes, with regard to its chemical and phys- 

 ical conditions ; third, the general character of the natural 

 vegetation upon the reclaimed lands during the past year, in 

 connection with the results of experiments carried on during 

 the same period. 



Various analytical examinations of the subsoil water, taken 

 from the centre of the marshes durinsf the summer of 1874, 



