270 
THE CULTIVATOR. 
Sept. 
ACTIOS ©F I9AEL AM© Hiffi, 
Editors of the Cultivator —In the article on 
<c Manures—Their Nature and Action,” in the June 
number of the Cultivator, an allusion was made to a 
mineral substance found in New-Jersey and farther 
south, and known as “ green sand,” which possesses 
very valuable properties as a manure. 
I suppose it would be useless for me to say anything 
about marl. To all who are interested in it, it is al¬ 
ready perhaps sufficiently w T ell known. As stated in 
the article referred to, “ its great value is chiefly due 
to the potash it contains.” 
But there is another mineral substance, which is 
found in a bed extending through a portion of the state 
from New Egypt to Vineentowm, and is found I think, 
a few miles south of Haddonfield. I allude to w T hat 
Prof. H. D. Rogers calls “a straw-colored limestone,” 
but more particularly to the thin limestone stratum of 
the vicinity of Vincentowm. This is not so well known 
nor so extensively found as the marl. Prof. Rogers’ 
analysis of it gives “ lime 49.69, carbonic acid 38.31, 
silica and other impurities, 9.00, water, 3.00—making 
about 88 per cent, of it carbonate of lime.” In speak¬ 
ing of where the beds of limestone had been cut through, 
by digging a well into the green sand stratum under¬ 
neath, Prof. Rogers saj^s—“ It w 7 as in thin irregular 
beds, separated by incohering r sand and calcareous 
grains, similar to the mixture which composes the rock; 
its total thickness w T as about six feet; the organic re¬ 
mains are the same w T hich characterize the limestone of 
Vincentown.” It is now 7 found in places from fifteen to 
more than twenty feet thick. But it is not the stone, 
to which I wished more particularly to call attention, 
but rather “ the incohering sand and calcareous grains” 
by which its strata are separated. 
If a test by effervescence with acid w T ould be suffi¬ 
cient to judge by, I should suppose that this incohering 
sand contains nearly or quite as much carbonate of lime 
as the stone itself. If so, perhaps it may be called by 
way of distinction, pulverized limestone. 
I suppose this bed of carbonate of lime was not pla¬ 
ced there for nothing. In what w r ay it may become 
useful to man, and to what extent ? are questions of 
some importance. How far will pulverized carbonate 
of lime answer in the place of quick lime ? 
I think Liebig advances the idea in his Chemical 
Letters, that one of the most importaht uses of lime 
on land is, that by its caustic property, it may assist in 
disintegrating the soil, and rendering the alkalis, or 
potash contained in it, capable of becoming soluble in 
water, and thus taken up by the fibrous roots of plants 
requiring it. 
And he illustrates this opinion by describing a plan 
for decomposing feldspar* a mineral which contains pot¬ 
ash, and forms a component part of the most widely 
diffused of the primitive rocks. In this case, I suppose 
the carbonate of lime would be of but little use. 
Yet some farmers who have been in the habit of 
using lime for many years, say they think a heap of 
lime, which has lain eighteen months or longer, and 
thus become principally carbonate, is quite as benefi¬ 
cial to the soil as one spread immediately after slaking. 
It is known that almost all marls contain ingredients 
injurious to vegetation. These are principally copper¬ 
as and alum. Although some contain a much smaller 
proportion of them than others; yet it is found that 
where land has been marled copiously for a number of 
years, a continued application of it, without lime, is 
attended with bat little beneficial effect, while the soil 
seems to acquire a strong inclination to produce sorrel. 
Prof. H. D. Rogers recommends as an antidote to the 
poisonous principles contained in marl, the use of “caus¬ 
tic or freshly burnt lime.” Yet a simple experiment will 
show that carbonate of lime wall decompose copperas 
or alum, as w 7 ell as the caustic. Take a little pulver¬ 
ized copperas, and mix it with a similar quantity of 
this pulverised carbonate of lime. Add a little water 
to the mixture. The appearance of rust or red oxide 
of iron in the mixture, wall show that the copperas 
(sulphate of iron) is decomposed; wdiile the efferves¬ 
cence will as surely indicate that the sulphuric is taking 
the place of the carbonic acid; and the latter being set 
free, in escaping causes the effervescence. In a simi¬ 
lar experiment with alum, in the place of copperas a 
like effervescence will as readily indicate a mutual de¬ 
composition. And a practical agricultural experiment 
would seem to accord with those of chemistry. 
A strip of land which had been marled several times 
within the last tw r enty years, (but had received no lime) 
w r as covered with a few loads of this pulverized lime. 
Two years afterwards, the part of the field manured 
with the lime bore a good growth of clover, while the 
other portions of it w 7 ere red with sorrel. 
In Playfairs edition of Liebig’s Agricultural Che¬ 
mistry, it is stated, that “ in China, the plaster of old 
kitchens which have no chimneys but an opening at the 
top, is so much valued as a manure, that they will 
sometimes put a new plaster on a kitchen for the sake 
of the old.” And the reason offered for the increased 
value of the plaster, is “ The ammon ; a contained in 
the fuel forms nitrate of lime wuth the lime in the mor¬ 
tar.” Is there not a portion of ammonia continually 
escaping in the summer season from every body’s barn¬ 
yard ? Would not a small portion of carbonate of lime 
spread over the yard, be as likely to retain it, as the 
plaster of a Chinese kitchen ? 
In the American Farmer’s Encyclopedia, article 
Bones, it is stated that the shells of the oyster, lobster, 
&e,, contain a small proportion of phosphate of lime. 
The pulverised portion of this limestone, w 7 as without 
doubt, formed by the decomposition of sea-shells. 
Were the marine shells of ancient times composed 
similarly to those of the present time? or have they 
been subject to a change in composition? And if they 
once contained phosphoric acid, would they be likely to 
retain it through so long an interval ? If this lime 
contains only a little phosphoric acid, those who make 
use of it need not be at the labor and expense of pro¬ 
curing bone manure for their land. 
It is true, there is no mention made of phosphoric 
acid in connexion with this subject in Prof. Rogers’ 
Geological Survey; but his analysis w~as only of the 
stone. Probably, the strata of stone w 7 ere formed by 
the shields of some animalculse,' similar to the madri- 
pore, and perhaps contained no sulphuric acid; while 
the pulverized mass which separates them, may have 
been formed by the disintegration of bones and shells, 
w 7 hich w 7 ere thrown together by the currents of the 
ocean. 
I cannot tell wdiether any of these speculations are 
correct; I only claim that the subject is an interesting 
one; and w r ould be glad either to change my opinions,, 
or be more confirmed in them. 
H. Grath, Jb 
New Jersey , July, 3848. 
