254 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



reduced by pounding- to the consistency of gravelly sand, where it had 

 previously exisited in the indurated or rocky state. Oats were then sowa 

 about the middle of April, three plants being allowed to remain in each 

 pot. The pots were plunged to the rim in an open border, cinders of coal 

 being put under them, and care otherwise taken that the roots of the oats 

 should obtain no extraneous nourishment. The plants were watered with 

 common spring water, a few times, in very dry weather. 



The stalks attained, in general, to the height of two-and-a-half to three 

 feet. The grain fully ripened about the beginning of September, 



PRODUCE. 

 Earths. Ears. Grains. 



Granite (Aberdeen) 13 220 



Clay slate (primitive) 11 241 



Greenstone (secondary trap) 10 245 



Limestone 8 251 



Chalk 13 355 



Gypsum (very sickly plants') 6 40 



Sandstone (silicious) 12 230 



Pit-sand (brown) 12 210 



Blue clay (10 feet below surface) 10 242 



Mixture of all the above kinds 9 190 



Common light loamy soil 18 453 



Experiments of this nature seem worthy of further prosecution, particu- 

 larly relative to the respective influence of the asmosphere and soil in the 

 nourishment of plants. When the oats were sown, scientific as well as 

 practical men predicted, that in most of these earths they would not 

 grow ; and when they saw them growing, predicted that they would not 

 ripen seed. The results have proved otherwise. 



A single experiment, in such case, can hardly be considered as decisive, 

 excepting as to the possibility of plants living and maturing in an unmixed 

 soil. The fact of their not succeeding, with one exception, so well in a soil 

 composed of the several varieties as in a simple soil, is likewise noticeable. 

 The superior success of the plants in loam is also to be observed, to show 

 that their growth was not wholly dependent upon the atmosphere, as some 

 would have us believe, and that the soil furnished something more than a 

 mere support for the plants. The growth, in each case, must be considered 

 as inferior; and without deducing any general conclusions, which might be 

 premature, or endeavoring to fit the facts to any received theory, I submit 

 it to the further inquiries of those who have the curiosity and talent to pur- 

 sue these interesting investigations. If it prompts to other well-conducted 

 experiments, my object will be answered. 



The bringing of any considerable quantity of inert soil to the surface is 

 obviously attended with uncertain results, so much depends upon the na- 

 ture and condition of the soil so brought up. At the Duke of Portland's, 

 at Welbeck, places were pointed out to me where the surface mold had 

 been removed, a portion of the subsoil taken away, and the mold or top 

 soil returned to its place; but in no instance was its previous fertility res- 



