38 THE AMEEICAN MONTHLY [February, 



By this comparison it is seen that the New Jersey marl is richer in 

 potash and oxide of iron, while the Fort Washington marl is richer in 

 carbonate of lime. The land in Virginia and Maryland was about the 

 first in America to come under cultivation, and many farms in this 

 vicinity and around Baltimore have been tilled for about two hundred 

 years- In the Northern States a systematic plan has been adopted for 

 enriching the soil, but no such plan has been adopted in Maryland or 

 Virginia to any great extent. We have here, however, at our very 

 doors the material to bring back to the soil the strength which has been 

 squandered during the many years of constantly taking from the soil 

 and putting nothing back in return. 



The marl beds of this locality are much more easily worked than 

 those of New Jersey, and the material is as well calculated to enrich 

 this soil as the New Jersey marl is to enrich that soil. The marl from 

 Fort Washington can be put on the field at a cost of 5 cents per bushel, 

 while in New Jersey, twelve or fifteen cents per bushel is often paid 

 for it by the farmer. 



The microscopical examination of this marl reveals its great value at 

 once. Bits of shell can be seen all through the sand. Each particle of 

 sand is covered by a fine green coat, which is probably vivinite. When 

 heated it changes its color from a light to a very dark green. The so- 

 luble portions of the marl are rapidly lost by exposure to the weather, 

 and so that whidi comes from deep down in the pit is much better than 

 that from near the surface. When it is placed upon the field it should 

 be lightly covered by the harrow and left for the snows and rains of 

 winter to disintegrate the mass and mix the soluble portions with the 

 soil. Thus we see that the farmers of this region have at their very 

 doors a rich fertilizer, which is cheap and abundant and easily pro- 

 cvued. 



As soon as its value is appreciated, as it now is in other parts of our 

 land, it is sure to revolutionize agriculture. The farming district about 

 Washington is one of the poorest in the United States, and in many 

 places farms are cheaper now than they were fifty years ago. I know 

 of a farm of 40 acres within eighteen miles of Washington, which can 

 be had for four hundred dollars, and that is about the average price per 

 acre for these worn-out fields. If, however, this natural fertilizer should 

 come into general use as it deserves, we would see all this changed, and 

 instead of the red and yellow clay hills, the tumble-down shanties and 

 general appearance of desolation which now confronts one on all sides in 

 the rural districts, would be rich fields, handsome farm-houses, and 

 well-filled granaries. 



Dr. Seaman said : The marl formations of New Jersey have peculiar 

 features, possessed by no others. They are unique in the large amount 

 of potash they contain. Large quantities of sharks' teeth are found, but 

 no diatoms. 



The method of digging the marl was then described, and also the 

 marl deposits on James river in Virginia. 



Prof. Foster said: While the Maryland marl is poor in potash, yet 

 it is equally true that the soil ol" Maryland and Virginia needs not so 

 much potash as carbonate of lime, and this the Maryland marl has. 



