“to improve the 
SOIL AND THE MIND.” 
New Series. 
ALBANY, 
APRIL, 1849. 
Vol. VI.-—No. 4. 
£hnestone Soil of Kentucky. 
Remarks on the Agricultural Value of the Blue Lime¬ 
stone of Kentucky; with its analysis: By Robert 
Peter, M. D., Prof, of Chem. in the Medical De¬ 
partment of Transylvania University, Lexington, Ky. 
The region in which Lexington is situated, has long 
been justly celebrated for the great and lasting fertility 
of its soil; which, by the production of its luxurious ve¬ 
getation, plentiful crops of corn, and herds of fat ani¬ 
mals, evinces that it is rich in the elements which are 
essential to vegetable, as well as to animal growth. 
Unlike the soil of many other parts of the world, 
heavy production does not quickly exhaust it. A field 
which has been cultivated in corn for twelve or twenty 
years, may be made almost as fertile as it was at the 
commencement, by resting it with a clover crop, or de¬ 
pasturing it for a time in grasses. It is, consequently, 
not the custom of the country to pay much attention to 
manures; and some of our farmers even consider the 
accumulations about their stables as a nuisance. 
Her fertile soil enables Kentucky to export, from her 
iich counties, an immense number of hogs, cattle, mules 
and horses, a large quantity of hemp, and a considera¬ 
ble amount of Indian corn. The corn crop in Kentucky 
for 1847, was estimated at 62 millions of bushels, and 
during the past year, (1848,) at least 250,000 hogs 
have been sent abroad, to be slaughtered and consumed. 
It cannot be supposed, however, that the soil will 
continue to maintain its fertility, under the immense 
drain made upon it by the exportation of its products; 
and old inhabitants have been for some time complain¬ 
ing that the long cultivated soil has undergone visible 
deterioration. 
Since chemistry has given her assistance to agricul¬ 
ture, the reason of this has been made very clear. 
Every product of the soil takes from it, in notable quan¬ 
tity, certain mineral substances which are essential to 
its growth and formation. These are known to be, al¬ 
kaline salts, sulphur and its acids, phosphoric acid, 
lime, oxide of iron, silica, &c. These substances are 
as essential to animal existence as they are to vegeta¬ 
bles; and both animals and vegetables can no more 
subsist or thrive with a deficiency of these mineral in¬ 
gredients than they can without water. 
The saline and earthy matters, which form the ashes 
of plants and their products, are the same which are 
essential to the bones and other solids and the fluids of 
the animal body. Where they are abundant in a soil, 
other things being propitious, the vegetation becomes 
rich and matures a plentiful harvest, and animals grow 
and fatten easily on the products; for the plant draws 
them from, the soil and works them up into forms adapt¬ 
ed to animal nutrition. On the contrary, where they 
are deficient in the soil, vegetation is scanty, and the 
animal races dwindle and starve. 
The fertility of the soil depends more on these mine¬ 
ral ingredients than on any other, although they really 
form the smallest relative proportion of the weight of 
vegetables and animals;—for the other ingredients of 
the organized bodies, viz: carbon, hydrogen, nitrogen 
and oxygen, are derived from the atmosphere and from 
water, which are universally diffused; while these mi¬ 
neral ingredients are the properties alone of the soil, 
and when present in sufficient quantity, even in pure, 
earthy matter of any kind, they stimulate the growth 
of vegetables, which by their final decomposition, soon 
fill the earth with humus, and form the rich vegetable 
mould. 
Amongst.the most important of these is phosphoric 
acid, which, in union with lime, magnesia, and perhaps 
oxide of iron, enters into the structure of all vegeta¬ 
bles, and the more nutritious the vegetable substance, 
the larger is its proportion of the acid. _The grains 
are peculiarly rich in it:—Boussingault remarks that 
no seed is known which does not contain it. Hence, a 
plant, growing on a soil which does not afford it, never 
matures its seed, and the production of seeds of any 
kind speedily exhausts a soil. 
Phosphoric acid is equally essential to animal growth, 
it being a constituent part of all the organs of their 
body, and particularly of their bones, the earthy matter 
of which being mainly phosphate of lime. 
An idea of the quantity of phosphoric acid which is 
annually taken from the soil, may be obtained by study¬ 
ing the chemical analyses of the ashes of vegetable 
substances. 
Indian corn gave me more than 1 per cent, of ashes, 
of which 50 per cent, is phosphoric acid. Wheat gives 
nearly 2| peret. of ashes of which more than 60 per ct. 
is phosphoric acid. Oats and rye contain it in but a lit¬ 
tle smaller proportion, and every 1,000 pounds of dried 
hay contains about 3§ pounds of this acid. In short, 
the ashes of wood and all vegetable substances, are 
rich in phosphates, and hence the utility of even leach¬ 
ed ashes as a fertilizer.* 
In every bushel of Indian corn sent out of the state, 
we export about one-third of a pound of phosphoric 
acid; and in the bones and body of every hog, there is 
at least two pounds of this substance; so that in her 
250,000 hogs, exported during the year just terminated, 
Kentucky has sent off at least 500,000 pounds of this- 
valuable ingredient of her soil. Taking into consider¬ 
ation the whole of her exports, in animal and vegeta¬ 
ble products, the amount of phosphoric acid sent every 
year from the fertile counties alone, must be much 
above a million of pounds. 
As this indispensable ingredient exists but in a small 
relative proportion in the best soils, continued export a - 
tion of products, without a corresponding importation 
of the mineral elements of animal and vegetable sub¬ 
stances, must impoverish the country. 
* I refer the reader to Boussiugauh's Rural Economy , (transla¬ 
ted by Geo Law. and. published in 1845, by Appleton. N. York' ) 
for many interesting facts in this relation ; and many reports of the 
analysis of ashes of vegetables are given by Dr. W. Knop. in the 
Vol. XXXVII of the Journal fur Praktische Chemie—y. 34. 
