35b TRANSACTIONS OF THE AMERICAN INSTITUTE. 



Let us know whether the long summer drought, as in India, 

 Africa, and elsewhere, except in this country, is the reason why 

 cotton will not succeed in California. Our repeated summer 

 thunder showers are believed to be indispensible to good crops of 

 cotton. Egypt grew cotton as she did grain and every thing else, 

 by irrigation from the Nile. 



The regular subject for consideration being taken up : 



MARL. 



Dr. Trimble. — There is a belt of land in the State of New Jer- 

 sey running from 'Sandy Hook in the east, southwest to Salem 

 county, on the Delaware river, about 90 miles in length by 14 

 wide in the east to six miles in the west, that has lying under it, 

 at a greater or less distance below the surface, this marl — this 

 great fertilizing and renovating material, that has already worked 

 such wonders in some localities, and Avhich is destined to bring- 

 about mighty results in the future. 



This belt comprehends 900 square miles, or 576,000 acres. 

 And as this material, by means of increased transportation, can 

 be made to overflow these borders, as the coals Overflow from the 

 mines of Pennsylvania, no one can calculate what the future has 

 in store from this source. 



To New Jersey it has already been worth millions of dollars in 

 the increased value of land and crops, wanting only labor, not 

 capital, to reward and encourage enterprise. 



The marl is found in three different layers. The first one found 

 principally in the uplands, and on farms where the surface is un- 

 even it may be found on almost every field. 



The other layers are seldom revealed except along the water 

 courses, but may be opened any where by digging. 



Its value was probably first made known by scattering the 

 earth taken out when digging wells. 



The beds of this marl run in particular directions according to 

 fixed laws, and they have rules by which they can be found. 



At the time when the geological surveys of the State were 

 made there was quite a difference of opinion as to what ingre- 

 dient was the cause of its agricultural value. 



Of those who have analyzed it : Seybert says it was potash, of 

 which he found ten per cent., that gave it its value. Some said 

 it was owing to its shells or calcareous ingredients, but very lit- 

 tle of these are found in the sand marls. Vanuxem said the iron 



