On the Greensand of New Jersey as a source of Potash. 327 
existence and common attributes of the greensand are 
miss. It exists in greater or less quantity in several States, but 
has its greatest development, I believe, in the State of New Jer- 
sey, where it forms a stratum of variable thickness, covering a 
terand Salem. Wheréyer.it occurs,, itis spread upon the land 
farmers, to whom it is known. by the name of Marl. Its proper 
ties as a fertilizeryare undoubtedly owing to the ease with which 
upon the Geology of New Jersey, in which he has devoted about 
a hundred pages to the greensand, and has given many. analyses 
Ww 
No analyst has, to my knowledge, found potash in the English 
Of greensand, others contain variable proportions of a red or 
_. brown earth and of quartz. A few contain more or less earbon- 
ate of lime in such a form that it is not acted upon by dilate 
_ acids in the cold, although upon the application of heat a violent 
_ @ffervescence. appears... Many contain iron pyrites and some a 
trace of sulphate of iron. No variety which I have ined 
_ has yielded any phosphoric acid. . Z 
ee The greensand grains themselves contain, besides potash, silica, 
alumina, one or the other or both of the oxyds of iron, and water, 
With sometimes a little magnesia. _ aealia! 
» The invariable development of a smell of formic acid by the 
ction of strong sulphuric acid upon them, seems to indieate the 
tesence of a little organic matter. Analyses of two varieties of 
the marl from the estate of the late Alfred Bishop of Bridgeport, 
at Shrewsbury, Monmouth County, yielded the following results - 
i TI. 
Rilitapc dae. ; ‘ ek ae ica el ee ied 
_ Alumin incipal xyd, 3289 34: 
& wag eo 9 of iron, ses aied erg y' sere art 
nesia, : ‘ . 
Hydroscopic water, . ‘ . : ; eet : 11:50 
Combined water, . ‘ : ‘ ' ~ iced sais 
| 10061 99-25 
It may be remarked here that Prof. Rogers's results were ob- 
tained upon the greensand grains separated as much as possible 
tom intermixed earth and sand, while the above were made upon 
_ the impure marl itself. 
~ The 
generally known, but a few words on this subject will not be » 
i 
great portion of the counties of Monmouth, Burlington, Glonces- 
the potash which it contains is abstracted from it by atmospheric* 
agencies, as is suggested by Prof. Henry D. Rogers, in his Report’. 
lich indicate the presence of from 10 to 13 per cent. of potash, 
Various. Some varieties are almost entirely composed of grains». 
cd 
greensand, the‘fertilizing properties of which appear to be due to ae 
