236 
THE CULTIVATOR. 
August., 
soil; it requires, however, only little attention to see 
the great error of this opinion. We observe that the 
effect of these substances is not equal on all fields; in 
one place the amount of produce is increased by the 
lime, by the bone-earth, and by gypsum; in another 
country, or on other fields, these substances in no way 
favor vegetation. From this arises the contradictory 
views of farmers regarding these matters as manures. 
If one farmer thinks the liming of his fields quite indis¬ 
pensable for rendering them fertile,—another declares 
that lime produces no effect at all. 
The reason of this difference is very simple. The 
examination of a soil, upon which lime has had no 
effect, shows that it was already rich in this substance; 
it further shows that its effect extends only to those 
kinds of soil in which lime is wanting, or in which 
it is found in too small a quantity, or in a condition 
which is not suited to its assimilation by the plant. 
Jnme especially serves for resolving the silicates of 
alumina (clay,) and consequently it cannot fertilize 
soils in which clay is wanting, for instance, sandy soils. 
It must be apparent to every one, that on the calcareous 
and gypseous fields of France and England one-half 
per cent, of gypsum or lime can have no influence at all 
on vegetation. This can be said with equal justice of 
bone ashes, and of every other mineral substance serving 
for the nourishment of plants. 
If these substances exercise a favorable effect, some 
of the constituents of the soil or manure are restored, 
which are indispensable to the nourishment of plants, 
and which have been wanting in the soil. If this be 
the case the other bodies, equally necessary, must be 
present in sufficient quantity. On a field, in which sul¬ 
phate of lime has acted favorably, and in which clover 
had been cultivated as fallow without it, the crop was 
2200 pounds of clover hay, in which 53 pounds of 
potash were removed. On the same field, after it had 
been gypsed, 8000 pounds of hay were produced, which 
contained 191 pounds of potash. If this potash had not 
been present in the soil, the gypsum would have had 
no effect,—the crop would not have been increased. On 
fields, which are richly provided with all the other 
mineral ingredients, with the exception of gypsum, the 
latter is applied with the greatest success. But if gyp¬ 
sum is present in the soil, the same effects are produced 
by ashes and lime, as is the case in Flanders. On fields, 
in which phosphate of lime is wanting, bone ashes in¬ 
crease the produce of grain, clover, or grass, and on 
argillaceous soil, lime produces a decided improvement. 
All these substances act only on those fields which are 
defective in them, and if the other elements of the soil 
are present. The latter cause the former to come into 
action, and vice versa. The farmers, who thought that 
by using lime, gypsum, bone earth, &c.. they might 
dispense with animal manure, very soon observed that 
their fields deteriorated. They observed that after a 
third or fourth successive manuring with those simple 
substances the produce decreased; that, as is the com¬ 
mon expression, the soil became tired of the manure, 
that at last the field scarcely produced the seed. 
It is evident from this, what is the action of the mine¬ 
ral elements in the soil. If in fact, in the first years, 
the produce of the soil had increasad by the application 
of bone ashes, or by a single element of the manure—if 
this increase was dependant on the amount in the soil 
of the other mineral elements, a certain quantity of 
those was annually taken up by the plants and removed 
in the harvest, and a time must at last arrive in which 
it is exhausted by the repeated removal; the soil must 
become barren, because of all removed elements, only 
one or the other, and not all of them, in a right propor¬ 
tion, have been restored. 
The right proportion of the supply is, however, the 
only true scientific basis of agriculture. 
If we subject the fluid and solid excrements of 
men and animals to an exact analysis, and compare the 
elements of them according to their weight, some con¬ 
stant. relations between these elements impress them¬ 
selves upon the mind, the knowledge of w%'seh is of 
some importance. 
If the excrements of an animal are collected with 
some care and left to themselves for some days, their ni¬ 
trogen appears to have been converted more or less 
perfectly, into ammonia. In the fluid excrements, in 
the urine, the salts of the food, which are soluble in 
water, are found in the form of alkaline carbonates, or 
of sulphates, phosphates, and other salts, with alkaline 
bases. In the solid excrements or foeces, silica, if it was 
contained in the food, earthy carbonates, and phos¬ 
phates, are the principal ingredients. 
The quantity of alkaline carbonates bears a certain 
proportion to the amylum, sugar, pectine, or the gum 
of the food. The urine of an animal which has been 
fed with potatoes or turneps, is rich in alkaline carbo¬ 
nates; the potatoes, however, consist principally of amy¬ 
lum; the chief ingredients of the turneps are sugar and 
pectine. The urine of a horse, which has been fed 
with hay and oats, is comparatively poor in alkalies, if 
compared with the former. 
It is further shown, that the ammonia or the nitrogen 
of the excrements bears a certain proportion to the 
phosphates; the azote increases or decreases with the 
quantity of the phosphates in a manner that both can 
serve, as a measure for each other, although not quite 
as an accurate one. It is not quite accurate, because the 
gum and the amylum also contain a certain, although 
small, quantity of phosphate of lime, as has been proved 
in my laboratory. 
The ammonia of the excrements is of course derived 
from the nitrogenous substances in the food; the phos¬ 
phates are likewise constituents of the latter. In the 
composition of the food an equally constant proportion 
exists between both. A given weight of gluten or 
casein in peas or in grain always corresponds with a 
certain weight of phosphates; if the grain or the vege¬ 
table is rich in those azotic products of vegetable life, it 
is also rich in phosphates; if it is deficient in them, the 
quality of the latter decreases in an equal ratio. 
As the amount of nitrogen in manure is a measure for 
its amount in phosphates, and as manure contains be¬ 
sides these also the other ingredients of the soil which 
are required by the grain or by the other vegetables for 
their development, and taken up by them from the soil, 
ic is easily conceived what was the cause of the error 
in regarding the azote of the manure as the principal 
cause of its efficacy. The reason was, that the ammo¬ 
nia of the manure is always accompanied by the mineral 
elements which affect its nourishing qualities, because 
they render its assimilation into the organism of the 
plant and its transition into a nitrogenous constituent 
possible. Without phosphates, and without the other 
mineral elements of the food of plants, the ammonia 
exercises no influence whatever upon vegetable life. 
If it has been shown that the fertility of the soil de¬ 
pends on certain mineral substances; if the restoration 
of the fertility of exhausted fields by means of the ex¬ 
crements of man and animals depends upon their pro¬ 
portions of these matters; if the effect of the manures 
accelerating the vegetation depends upon their propor¬ 
tions of ammonia, it is clear that we can only dispense 
with the latter when we provide all efficacious elements 
exactly in those proportions and in that form most 
proper for assimilation by the vegetable organism in 
which they are found, in the most fertile soil or in the 
most efficacious manure. 
According to our present knowledge of the effect 
of the constituent parts of manure, I feel convinced 
that it is indifferent to the plants from which source 
they are derived. The dissolved apatite (phosphate 
of lime) from Spain, the potash derived from the fel¬ 
spar, the ammonia from the gas works, must exercise the 
same effects on vegetable life as the bone earth, the 
potash, or the ammonia, which we provide in ma¬ 
nure. 
We live in a time when this conclusion is to be sub¬ 
jected to a comprehensive and accurate trial, and if the 
result corresponds with the expectations which we are 
entitled to make, if the animal excrements can be re¬ 
placed by their efficacious elements, a new era of agri¬ 
culture must begin. 
I invite the enlightened farmers of England to unite 
with me for that purpose, and to lend me their ait». 
