THE CULTIVATOR. 
171 
DICTIONARY OF TERMS 
USED IN 
Agriculture and its Kindred Sciences. 
DIGESTION. In order that the substances used by 
man and animals as food may become nutritive, they 
must first undergo the process of digestion. When the 
articles of food, properly masticated and prepared by the 
saliva, are taken into the stomach, they are subjected 
to an action by which they are mechanically separated 
into their smallest parts, saturated with the gastric 
juices, and converted into a pulpy or half-fluid mass. 
This mass on leaving the stomach is called chyme, and 
that part of the large intestines called the duodenum, 
is mixed with the pancreatic juices and the bile. By 
the action of these substances a new product called 
chyle, is produced, of a milk-like consistence, which is 
absorbed and taken up for circulation, and the nourish¬ 
ment of the system, by the vessels called the lacteals. 
The function of digestion is one of the most important 
in the animal system, since when this is deranged, none 
of the rest can go right; and by far the largest amount 
of disease known to man or animals arises from this 
source. Digestion may be impaired by the want of 
proper food to excite the stomach to action, or it may 
be impeded or fatally obstructed, by overtaxing its ca¬ 
pabilities, or loading that organ with substances difficult 
of reduction or assimilation. Those substances that af¬ 
ford the most nutriment, are not always the most easy 
of digestion, and are not of themselves the best adapt¬ 
ed for food. It seems necessary there should be a con¬ 
siderable quantity of material not decidedly nutritive, 
mixed with the positive nourishment, in order to pre¬ 
vent the stomach’s receiving too much of this, and be¬ 
coming clogged and inactive. Some of the substances 
that are composed of concentrated nutritive matter, 
such as pemmican, (essence of beef,) or sugar, will 
support life but a short time, and are injurious in large 
quantities. Fhre wheat flour is objectionable as con¬ 
taining too much nutriment in proportion to its bulk; 
and animals fed entirely on wheat or barley, without 
coarser food to distend and excite the stomach to ac¬ 
tion, are very sure to suffer. It seems essential to a 
healthy state of the digestive organs, that the food 
should be of good quality, abundant; the nutritive and 
coarser parts properly proportioned; that it should be 
received at regular times, and so often as to prevent an 
inclination to overload the stomach ; that eating should 
not be followed at once by severe exertion, and that no 
substance should be taken into the stomach till properly 
masticated. 
DILUVIUM. Over the surface of almost every coun¬ 
try on the globe are scattered beds of gravel, sand, and 
boulders, evidently once subjected to the action of wa¬ 
ter, and deposited in their present position by power¬ 
ful, and as it would sometimes seem, conflicting cur¬ 
rents. The boulders mingled with diluvium, or rather 
constituting a part of the mass, form one of the surest 
means of determining the course of such currents, as 
they may usually be traced back to their original de- 
posite or strata. It is obvious that the currents, what¬ 
ever caused them, which have deposited the diluvium 
of the United States, flowed from the northward. In 
Massachusetts, New-York, and Ohio, this evidence is 
incontestible, and in passing from Boston to Buffalo, 
and thence to St. Louis, one is continually meeting witli 
boulders, which could only have had their origin from 
20 to 100 miles northward of the route traveled. The 
feldspar, sienite, graywacke, lime, and sandstones of 
the several districts, are so well known, that it is not 
possible for an experienced observer to mistake or 
confound them; the only wonder is, how such mass¬ 
es of granite and sienite as are sometimes found one 
hundred or more miles from their original location and 
weighing from ten pounds to as many tons, should have 
been placed in their present positions. Diluvium ex¬ 
ercises an important influence on agriculture, and by 
knowing the particular location of any kind of rock, we 
are able to trace the direction of its influence, and the 
effects produced by its partial breaking up and degra¬ 
dation. 
DIP. This is a term applied to the direction of the 
layers of rock that constitute the crust of the globe. It is 
very various in the same strata and in the same country; 
the layers sometimes exhibiting the most remarkable 
bendings and contortions. The dip of the transition or 
secondary rocks furnishes the best opportunity for ob¬ 
serving its effects. A knowledge of the dip of the strata, 
may be of essential service in determining the place in 
the series of any particular rock. Thus much money 
has been in former years expended in Middle and Wes¬ 
tern New-York, in boring for coal, under the supposi¬ 
tion that as that section of country was higher than the 
coal fields of Pennsylvania, boring to that supposed le¬ 
vel would reach similar deposites, when an examina¬ 
tion of the strata and a calculation of the dip, has shown 
that these beds of coal are geologically some three or 
four thousand feet higher than the place where the bor¬ 
ings were attempted. 
DISEASES. In all animals, as well as in man, there is 
a tendency in the young to follow the type of the parent 
in general appearance and internal conformation, and 
this disposition causes the diseases of the parent to ex¬ 
ercise a decided influence on the health and vigor of their 
offspring In man this tendency to hereditary disease is 
more noticed than in the animal, but it is as active in one 
case as the other, and if it does not as often show itself 
in the last as in the first, it is because the counteracting 
energies of nature, when left unfettered by conventional 
rules or absurd modes, are sufficient to modify, if not 
to prevent, the injurious consequences of such tendencj". ( 
Diseased or malconformed animals should, however, 
always be avoided for propagation, especially those in 
which the chest is defective, since an animal with a 
narrow chest, cannot have the room for the free circu¬ 
lation of blood and action of the lungs required in a 
perfectly healthy state. 
DISTILLATION—is a process in which certain sub¬ 
stances existing in, or combined with others, are sepa¬ 
rated, by first being converted into vapor by heat, and 
then condensed by cold. Volatile oils, essences, alco¬ 
hol, spirits, brandy, &,c. are the products of distillation, 
and the products so obtained are exceeding useful in 
the arts and sometimes when exhibited as medicines. 
The great use of distillation is, however, to produce in¬ 
toxicating liquids from the various substances capable 
of furnishing them, and the cheapness and consequent¬ 
ly general use of these products, has caused the most 
frightful demoralization in almost every country. All 
the small grains, corn, potatoes, cider, wine, yield the 
intoxicating material, and most of those nations in 
which the regular process of distillation is unknown, 
have the means of producing inebriating drinks by 
simpler, yet scarcely less effectual, if not equally com¬ 
mon means. Alcohol, and the oils prepared by distilla¬ 
tion, are found of great use as solvents, and subserve 
many useful purposes in the arts. 
DISTRIBUTION OF PLANTS. While there is 
scarcely any part of the globe on which plants are not 
found, many of the most important ones are confined by 
certain causes to particular zones or locations, and at¬ 
tempts to produce them in other situations must of ne¬ 
cessity be abortive. Thus, the palm of the tropics and 
the maple, of the arctic circle cannot be made to change 
places; and the same law applies to the apple and the 
orange, the Irish potato and the yam. The grand mo¬ 
difying agent in the distribution of plants, is tempera¬ 
ture ; and this cause divides the vegetable productions 
of the globe into zones, north and south of the equator, 
regularly marked, unless influenced by causes local in 
their nature and action. There are some general rules 
applicable to the investigation of the laws that govern 
distribution, which cannot be overlooked; and these 
are difference in latitude and difference in elevation. 
It has been found that the average difference in tempe¬ 
rature on any given degree of longitude is about equal 
to a degree of Fahrenheit for every degree of latitude; 
and that in elevation, there is on an average, a decrease 
of temperature equal to a degree, for every five hun¬ 
dred feet of ascent. The result of these laws is, that 
plants of the temperate zones, which will not grow 
on the plains of the tropics, flourish on the sides of the 
mountains or the elevated plains, the temperature re¬ 
sembling that of their favorite clime. Thus wheat and 
barley which cannot be grown on the plains of the tro¬ 
pics, produce abundantly on the table lands, some eight 
or ten thousand feet above the sea. The effect of 
these laws of distribution are sensibly felt in the United 
States, in the production of fruits and of grain. Thus 
the apple which finds its favorite clime in the northern 
states, does not grow in the southern ones; and the 
peach of the north is so inferior to that of the south, as 
scarcely to be considered the same fruit. The proper 
uffieat zone of the United States may be said to extend 
only from the 38th to the 43d degree of latitude. It is 
indeed cultivated both to the north and the south of 
these limits, but experience proves that the crop is less 
certain and the grain less perfect without than within 
them. In the northern states corn is not as certain a 
crop as it is in the south, but as far north as it succeeds 
the produce is usually more abundant, and the grain of 
a far better quality than that grown farther south. In 
the United States the zone best suited to the production 
of wheat and maize may be said to be coincident, or oc¬ 
cupying the same degrees of latitude. In England and 
on the Continent, the temperature produces a different 
result, the wheat and the maize zone being distinct; and 
it being impossible to grow corn as far north as the 
best wheats are produced. 
DOCK. This plant is the Rumex of the the botanists, 
and several have been introduced from abroad for cul¬ 
tivation in our gardens, that have become most trouble¬ 
some weeds. Although some sixty species of this 
plant is known, only five or six are natives of the Unit¬ 
ed States. The dock is familiarly known by the names 
of broad leaved and narrow leaved, and these two plants 
give the most annoyance to the farmer. Fortunately 
the dock does not, like the Canada thistle, spring from 
the lower roots when the crown of the plant is cut off; 
and all that is necessary, therefore, to eradicate it, is to 
strike it off below the surface. If this is done cleanly 
and at once, the plant is destroyed. 
DRAINING. The reasons for draining exist in the 
nature of the soil itself, and that of the earths of which 
it is constituted. The object of draining is to free the 
soil from superabundant moisture, render it more per¬ 
meable to atmospheric action, and thus give it friability 
and productiveness to a greater degree. Thorough 
draining is one of the greatest of modern improvements 
in agriculture, and has already redeemed millions of 
acres from a worthless state, and converted it into soil 
of the most valuable kind. Draining has been practiced 
from the earliest ages, but it was confined to freeing 
lands from their surplus water, and beneficial as this must 
have been, it could be considered as nothing more than 
a preparatory step for further operations. A very large 
proportion °f the cultivatable lands of all countries is ba¬ 
sed on a sub-soil more or less retentive of water, gene¬ 
rally hard and tenacious, and allowing water to pass off 
very slowly, or by the process of evaporation. If near 
| the surface or within eight to twelve inches, the effect 
on the crops grown is very injurious; if from twenty to 
thirty inches below the surface, the effect in the reten¬ 
tion of water is much less. To furnish additional 
means for the escape of water so retained, and which 
becoming stagnant is prejudicial to plants, is the great 
object of the modern system of draining. In thorough 
draining, the depth of the drains and their frequency 
must depend on the nature of the soil, and the quantity 
of water to be thrown off. The best method, or rule, 
appears to be, to have them so placed that no water 
shall be permanently retained nearer the surface dhan 
thirty inches. Ditches or drains are dug at the requi¬ 
site distances, so planned that the water shall flow free¬ 
ly to some given point of discharge, to the depth of 
from thirty inches to three feet, as circumstances re¬ 
quire ; width at the top some eighteen inches, at the bot¬ 
tom ten or twelve. The filling of the drains is perform¬ 
ed variously. The most common is to place stones 
against the sides of the drain, at the bottom, and on 
these place others, so as to form a covering to an open 
space, for the passage of the water. On these, others 
are thrown in loosely till the drain is filled a foot or 
more. On this, the turfs thrown out, are placed invert¬ 
ed, or else straw is thrown upon the stones and then 
the drain is filled in with earth. The straw or the turf, 
must be below any depth that will be reached by the 
plow, or the covering of the drain will be disturbed, and 
the passage of the water obstructed. In some parts of 
England and Scotland, what are called draining tiles 
are made of clay, so constructed as to be placed in the 
bottom of the drain, forming a permanent passage for 
water, and when well made very durable. Land, when 
thoroughly drained, speedily loses its tenacious hard- 
pan character, and becomes suitable for all kinds of 
grain grown on the most favored soils of the district j 
manures produce their proper action, the roots of plants 
have room to expand in search of food, and sour worth¬ 
less lands are effectually cured. Open drains are im¬ 
portant for carrying water from low lands on which it 
is apt to accumulate in quantity, but are inadmissible 
on cultivated lands, as obstructing the plow. A large 
quantity of the richest land in all countries, exists in the 
shape of swamps and morasses, and draining, open or 
thorough, is fast bringing these into an available state. 
There are very few farms in the country" on which 
draining would not be more or less useful, and on which 
it must be sooner or later employed. 
DRILL. In agriculture a machine employed in sow¬ 
ing seeds is termed a drill, and the process of sowing 
seeds with such an implement, drilling. The drill bar- 
row is comparatively a modern invention, and it has 
been adapted to sowing or planting nearly or quite all 
the small seeds cultivated in the garden or the field. 
The advantages of drilling over the common method of 
planting, are, the business is performed more expedi¬ 
tiously, the seeds are more evenly distributed, and they 
are covered at the depth most suitable for their vege¬ 
tation. The drill is used, in some districts of England, 
extensively for sowing wheat, and on the Holkham 
farm in Norfolk, (Mr. Coke’s, now Earl of’Leicester,) 
four hundred acres in a season are sometimes put in by 
this implement. Where the drill is used, the soil must 
be fine, free from stones or other obstructions, and then 
drill sowing is performed with the greatest accuracy 
and benefit. The Norfolk drill, sows from twelve to 
sixteen rows of wheat at a time, at a distance of eight 
inches. The sowing of wheat by this mode gives op¬ 
portunity for hoeing and weeding it, both of which are 
practiced when necessary, on the Holkham estate. The 
corn planter, which is coming into use in this country, is 
a drill of a valuable kind, and where corn is cultivated 
extensively will be one of the most important labor 
saving machines. The root culture has aided much in 
diffusing a knowledge of drilling, and on suitable soils, 
the practice promises soon to become general. 
DRY ROT. This is the name of a disease in timber, 
produced by a fungi, which, fixing on the timber pene¬ 
trates by the pores, producing a rapid decay or decom¬ 
position of the wood, and rendering it worthless. It is 
called the dry rot, because if it does not attack timber 
when dry, yet it continues, when once it has obtained a 
foothold, unlike other funguses, to spread,no matter how 
dry or secure from atmospheric action the timber may 
be placed. The rapid decay of timber used in modern 
structures, particularly in ship building, when compared 
with its former durability, proves that it is comparative¬ 
ly an evil of recent date. It occasions the most serious 
losses to all governments that find it necessary to keep 
extensive navies in existence ; since examples have oc¬ 
curred in Europe, and we believe in this country also, in 
which ships have been launched, and before being sent to 
sea at all, when a delay of a year or two occurred in their 
fitting out, had become so damaged by the dry rot, as to 
be condemned as unseaworthy. By order of the British 
government, extensive experiments have been made to 
test the various remedies that have been at different 
times proposed as preventives of the dry rot; but though 
impregnating the wood with some of the mineral poi¬ 
sons, as corrosive sublimate, or strong solutions of cop¬ 
per or zinc, have in some cases been found of advantage 
in preventing the disease, it is declared that no means 
of checking the evil, can be depended upon, except that 
of removing the infected wood from the sound part and 
giving a free circulation of pure dry air. Moist, warm 
situations are most productive of dry rot, and it may be 
artificially produced by extracting from the wood its oxy¬ 
gen, which leaves it in a state resembling the dry rot— 
unaltered in form, but breaking on the slightest resistance. 
Numerous shipwrecks occur, and many lives are annually 
lost, by the unsuspected ravages of this formidable fee. 
