306 
AMERICAN AGRICULTURIST. 
[August, 
these are the comfort of the cattle, and the quan¬ 
tity and quality of the manure. The bedding 
should be sufficiently deep and compact, to absorb 
the moisture and cover the droppings, and get not 
so much so, as to leave a mass of mixed straw, in 
place of good manure. It should also be amply 
sufficient to keep the animals clean and comfortable. 
The frequent summer showers should also be pro¬ 
vided for, and the hollow places in open yards 
should be so well littered, that pools are not 
formed, or if they are, that they are covered over 
or filled with straw, or other proper absorbents. 
In course of time, 'when it comes to be admitted 
and believed, that the making of good manure, is 
a sufficiently important part of the farm business, 
to receive the consideration it deserves, we shall 
doubtless have before long covered yards and 
sheds, expressly for the making of manure. 
The Leaf and Its Work. 
The leaf has been called the laboratory, or work¬ 
shop of the plant, and a view of its interior should 
interest every cultivator. Let us examine, as for 
example, a leaf from a Lilac bush (fig. 1, a); we find 
here two principal parts, namely: the frame work, 
consisting of the stalk, mid-rib, veins, and veinlets, 
Fig. 1.— LILAC LEAF AND SECTION. 
and the soft green “pulp ” which fills up the space 
between the fibres of the frame-work. The “ skel¬ 
eton leaves,” often made for ornament, have all of 
the soft green part removed, and only the frame¬ 
work remains. To look more closely into the green 
tissue or “pulp,” a thin cross section of the leaf 
must be made, as indicated by the short, dark line 
from which the dotted lines, b, proceed. Having 
made a very thin slice by means of a sharp razor, 
we place it upon one side 'on a moistened strip of 
glass, and look at it with a Compound Microscope. 
We find that the section of the leaf consists of a 
number of oval and rouudish bodies, or cells, cl, e. 
We also notice a difference between the two sides of 
the section—on the upper side, b, there is a row of 
small, clear cells. This row of cells belongs to the 
skin of the leaf ( Epidermis.) A similar layer of 
cells, c, is seen on the under side. This skin, or 
epidermis, covers the whole leaf, and from many 
leaves, such as the “ Live-forever,” it may be 
peeled off as a thin transparent film. Beneath, and 
CL. 
Fig. 3.— SECTION AND SURFACE VIEW. 
next to the upper layer of epidermis, there is a row 
of long cells placed closely side by side, below 
which the softer tissue of the leaf is found, its cells 
being irregularly placed and touch one another at 
only a few points. There are many open places be¬ 
tween the cells, called intercellular spaces. In the 
epidermis of the under surface (and to some extent 
the upper) of the leaf are small openings, or breath¬ 
ing pores, the stomata, which consist of an orifice 
surrounded by, usually, two guard cells. In figure 
3 a very small part of a leaf is shown in section, a, 
d, a portion of the lower surface, b, in view, with a 
number of these stomata open, and in place, c. The 
guard-cells—which are of a green color—are so 
delicately adjusted that they will contract or en¬ 
large according to the conditions of the atmosphere, 
thus closing these little mouths in dry weather, 
and opening them when circumstances demand. 
In the Lilac we have estimated that there are 
18,000 of these minute pores to every square inch 
of leaf surface, but in some plants the number 
reaches 170,000 for the same space—they are of 
course very small. Figure 3 shows two of these 
stomata, more highly magnified—one open, a, and 
the other closed, b, also the same seen in cross-sec¬ 
tion, c and d. The guard-cells, e,f, are darker, with 
a thicker and more granular contents. 
To return to the green cells of the interior of the 
leaf, we find upon separating them that their green 
color is due to minute granules of that color con¬ 
tained within the thin, colorless wall of the cell. In 
figure 4, a, is one of these cells, highly magnified. 
It is an irregularly shaped bag or sac in which the 
green granules ( Chlorophyll or leaf-green) are con¬ 
tained. A separate grain of Chlorophyll is shown 
at b, still more highly magnified. The millions of 
Chlorophyll grains which a single leaf contains, and 
to which its green color is due, are composed of 
protoplasm, and together constitute the laboratory 
of the leaf, in which the many wonderful changes 
are wrought whereby the food which the plant gets 
from the soil and the air is made into the organized 
material upon which animals live. The crude ma- 
Fig. 4.— LEAF-CELL AND CHLOROPHTLL GRAIN. 
tcrials upon which the plant lives come from the 
soil dissolved in water, and from the air in the form 
of gases, and reaching these little green grains of 
Chlorophyll, they are, under the action of the sun¬ 
light, changed into starch, sugar, and other pro¬ 
ducts of vegetable life. We have thus found the 
seat of the work of assimilation, but how it is done 
is mere speculation to the wisest. It is well estab¬ 
lished that these green grains do the wonderful and 
important work of preparing the materials for plant 
growth, and, that they may be spread out to the 
sunlight, and also be so placed that the crade ele¬ 
ments can reach them readily, they are stored in 
their walled cells (fig. 4, a), and these are packed 
rather loosely together and held in place by a 
strong transparent layer of cells making the skin 
or epidermis. Besides this, there is a stout frame¬ 
work of woody fibre to hold all in full exposure to 
the air and sunshine. This woody fibre also con¬ 
nects the leaf with the roots, so that the watery 
solutions from the soil may be brought to the 
Chlorophyll grains in the leaf. These solutions, as 
taken up by the roots, are extremely dilute, and 
have to be “boiled down ” or concentrated; this 
is done in the leaves under the heat of the sun, and 
the watery vapor as it forms must have a ready 
place of exit. This is amply provided for by the 
many stomata in the epidermis of the leaves. The 
amount of water that is thus transpired is enor¬ 
mous, and is reckoned by tons in a single day from 
an acre of ordinary vegetation. These same open¬ 
ings provide for the admission of the carbonic acid 
gas from the atmosphere, from which the carbon 
is taken to form an important constituent of the 
various products of the plant, while the oxygen 
set free is returned to the atmosphere. 
Bone as a Fertilizer.—Preparation. 
For about 30 years bones have been treated 
with acids, to reduce them to a soluble condition, 
or to break them down into a fine powder. When 
thus treated the residue is known as superphos¬ 
phate of lime. But we now speak of them in their 
natural condition, and refer to methods of pre¬ 
paring them for use. Every farmer in the country 
can save a considerable quantity of bones of home 
production, and by a little trouble and attention can 
collect a large quantity from the dwellers of 
villages in his vicinity. We once gave notice to 
the boys in a village of 5,000 inhabitants, that we 
would pay 12i cents a bushel for all the bones 
brought to a certain vacant lot; as the result more 
than 60 bushels were found and brought in wheel¬ 
barrows and baskets. Two boys who worked 
together, struck a “ find ” in an out of the way 
place, and from that and other places accumulated 
34 bushels, and were very rich with their §3 re¬ 
ceived for them. In this way one can often secure 
at least as much bone as will return to his land a 
large portion, if not the whole, of the annual waste 
of phosphates. To overcome the difficulty of mak¬ 
ing use of them in a raw and unbroken state, the 
bones may be burned in a slow fire, preferably in a 
heap of brushwood, chips, or similar refuse. By 
slow burning all risk of waste from over-heating is 
avoided. When burned the bones are easily crush¬ 
ed to a fine powder, and then contain all the sub¬ 
stances found in raw bones, excepting the nitrogen. 
This loss, however, cannot be helped, and it is bet¬ 
ter to submit to it than to neglect to use the bones. 
By grinding raw bones in powerful mills they 
may be reduced to a fine powder, and in this 
condition are known as ground bone, bone dust, 
bone meal, and bone flour, according to the coarse¬ 
ness or fineness to which they are reduced. Thus 
prepared they are articles of general merchandise, 
and are kept for sale wherever bones are to be pro¬ 
cured, or the prepared bone is in demand. The 
raw, unbroken bone is worth in the market about 
1 cent a pound, when ground it is sold at prices 
varying from II to 3 cents a pound by the ton. 
When the bone is “ raw,” that is, in its natural and 
fresh condition, it contains all its nitrogen ; but 
when steamed to extract glue, the nitrogen in 
great part is removed, and the bone is less valuable. 
On account of the difficulty of preparing bone with¬ 
out the requisite machinery, and the cheapness of 
the prepared article in the market, it is always 
preferable to procure the ground bone made by re¬ 
liable manufacturers ; otherwise the bones can be 
collected and prepared by burning, as above men¬ 
tioned. Bones are valuable to put into the soil 
under grape vines and fruit trees. Clusters of roots 
will grow around and feed upon them for many 
years, or until they are entirely used up. They can 
be broken with heavy hammers, or even be put in 
whole—a peek to a half bushel scattered about in 
the soil where they will be reached by the roots. 
ISeep (Ians.—The convenience and economy of 
space afforded by the deep can system of setting 
milk for cream, is more and more apparent as time 
passes. Many persons are changing from shallow 
pans to deep cans or pails, but we have not heard 
or known of one who has changed from deep to 
shallow setting. There is no necessity for a pool 
or spring, now that an excellent creamery or setting 
box in which ice-water can be used, is to be pro¬ 
cured at a reasonable price. The Cooley Creamery 
answers every purpose of a cold spring, with some 
advantages that the latter lacks. The yield of but¬ 
ter may not be greater, but it is of better quality 
with the deep pans, and will keep much longer. 
