F^AHMERS' REGliStER— GREEN SAND, OR NEW JERSEY MARL. 131 



ehoukl be left unturned in pursuit of so important 

 a discovery. 



The New Jersey green sand is generally found 

 in the valley and meadows, though occasionally 

 it rises to some height in the suiTounding hills. 

 Its depth in many places is very great, and several 

 strata occur, separated by layers of shells, or blue 

 clay, or sand colored by iron. The general aspect 

 of the green sand is that of a bank of moist bluish 

 clay — though in some places the green tint is very 

 percepttble. This however only occurs where the 

 earth is dry. When thrown into heaps by the 

 side of the pit, the mass falls into a coarse pow- 

 der, in texture and color very closely resembling 

 gunpowder, on which account it is verj- commonly 

 known by the name of gunpowder marl. This 

 mass consisis in very large proportion of the pure 

 green sand, having a slight admixture of clay, and 

 in many places of minute fragments of shells. 

 Occasionally, the bank presents a mass of the pure 

 green sand itself — and again, in some places the 

 shells predominate. In one of the beds in tlie vi- 

 cinity of New Egvpt, I discovered small spiculte 

 of gypsum, or nuij)hate of lime: but this occurred 

 at no other locality— -and in this place the cr}-stals 

 were so minute and few in number as to require 

 the use oi^ a microiHcope to be' seen distinctly. The 

 moist marl when warmed in the hand exhales a 

 strong phosphoric odour, a fact which I believe 

 has not been hitherto remarked. 



As already observed, the marl freqaently con- 

 tains shells both in an entire and broken condition. 

 This however is by no means universal. In fact, 

 the great majority of those beds in actual use con- 

 tain either no calcareous matter, or a very minute 

 proportion of it. Tiiis I ascertained by chemical 

 examination. In the vicinity of Arney's Town, 

 Crosswick's Creek, and Shrewsbury, as well as 

 other places, much of the marl which the farmers 

 spread over their land, contains no carbonate of 

 lime; while at New Egypt the calcareous and non- 

 calcareous marls are both extensively employed. 

 The same is true likewise, of the beds farther 

 south at Muliica Hill. The green particles them- 

 selves have an invariable composition — and those 

 of our Virginia marl beds are perfectly identical 

 •with those of the New Jersey deposite. Thirty 

 grains of the green sand pelded by careful analy- 

 sis — 



Silica, 



Protoxide of iron, 

 Potash, 

 Water, 

 Magnesia, a trace. 



15.51 grs. 

 7.56 " 

 3.10 " 

 3.00 " 



These results agree ver\' closely with the deter- 

 mination of Berthier of France, a,nd Seybert of 

 Philadelphia. The former operated upon the 



freen sand of Europe, the latter upon that of 

 few Jersey. It appears therefore that the pre- 

 dominant constituents are silica and oxide of iron. 

 The potash, amounting to about ten per cent, is 

 most probably the ingredient chiefly concerned in 

 the agricultural agency of the marl, though in 

 what way its connexion with the other ingredients 

 is severed w^hen the marl is spread upon the land, 

 I am at a loss to conjecture. 



Throughout all the district in which this depo- 

 .«ite occurs, it is extensively employed in agi-icul- 

 ture. In the neighborhood of Arney's Town, one 



of the points which I visited, it has been used aa 

 a manure for tiie last thirty years — but its general 

 introduction is of more recent date. In the region 

 in which the marl chiefly abounds, the soil is 

 loamy, having in some places a large intermixture 

 of tenacious clay. East of this tract, which is a 

 narrow band nearly parallel to the Delaware Ri- 

 ver, the countiy assumes an appearance very si- 

 milar to that of the sandy lands of Eas:ern Virgi- 

 nia, covered with a thick growth of pine, and com- 

 paratively unproductive. On both theses varieties 

 of soil the green sand is continually used with the 

 most striking benefit. For the clay soils, the more 

 sandy marls are of course pre fenced; and for the 

 sandy soils, those which contain some clay along 

 with the marl. The proportion in common, use 

 near Arney's Town, is from ten to twenty loads 

 per acre. In other places five loads or even less 

 is found to be sufficient. The action of the marl 

 appears to be very permanent, as will be evinced 

 by the following statement. In a large quadran- 

 gular field over which I walked, four successive 

 applications of the marl had been made at inter- 

 vals of four years — commencing about twenty 

 years ago. The first dressing was applied to the 

 north side — the second to the south — the third ta 

 the east, and the fourth to the west — while a small 

 space in the centre was left without any marl. AH 

 four sides were covered with a verj' heavy crop of 

 clover, which was nearly, if not quite as luxuriant 

 on the north as eitlier of the other sides — while 

 the space in the middle was almost, bare. The 

 action of the marl appears to be most powerililly 

 felt by clover and gTass — but it is very conspicu- 

 ous also with small. grain and corn. A very intel- 

 ligent farmer told me that it more than tripled hia 

 clover and grass crop, and doubled liis small ^rain. 

 In general it is spread upon the clover every fourth 

 year, and ploughed in for the next crop, Tliat it 

 is very efficient upon sandy soils is e\-inced by the 

 following striking fact. Some years ago an en- 

 terprising flirmer near New Egypt, purcliased 

 two hundred acres of the Pine Barren, which, by 

 marling, he has converted into pasture sufiicient 

 for one'^ hundred head of cattle. Such is the de- 

 mand for the marl, even at a considerable distance, 

 that it has become an article of great profit to the 

 proprietors of the pits, and more than one individu- 

 al was pointed out to me who had risen to wealth 

 by the sale of marl. 



* From what has been stated it will at once be 

 e-ddent, that the discover}- of extensive and acce.s- 

 sible beds of this manure in Virginia would be a 

 most important accession to the resources of the 

 state, and that an active and diligent search ought 

 Ibrthwith to be commenced throughout all the re- 

 cfion in which there is a probability that it exists. 

 Every aid which it is in my power to give, will be. 

 cheerfully bestowed in furtherance of this inquiiy: 

 and as Ifeel the double interest of a scientific cu- 

 riosity, and a sincere solicitude for the agricultural 

 prosperity of our state, I shall gladly receive all 

 fossils and other specimens whicTi may be trans- 

 mitted for inspection or analysis, giving them a 

 prompt attention, and communicating in reply such 

 liints as may promise to be most useful in this 

 deeply interesting and important investigation. 



WM. B. ROGERS. 



