Dodge City times. [volume] (Dodge City, Kan.) 1876-1892, 1878-04-13
Chemistry Of q Hens Egg.

the breakfast-table, ever think of the
wonderful nature of the structure they
crush, or Of the complex chemical ma
ture of the contents consumed as food.
To a large majority of people, an egg
is an egg, and nothing more. If the
multitude were inclined to inquire into
the composition of this curious embry-
otto substance, the Impotence of hum
ger which universally prevails at the
commencement OF the morning meal,
would render the hour quite unpropi-
tinus, and, therefore, we hardly expect
TO secure the readers attention until the
time arrives for lighting the evening
lamp.
Before proceeding to inquire into the
interior composition OF the egg, we will
consider the exterior covering, or the
shell, the physical and chemical struc-
ture of which is exceedingly interesting
and wonderful The white, fragile cor
tex called the shell, composed of mine
raj matter, is not the tight compact
covering which it appears lobe, forit is
everywhere perforated with multitude
of holes, too small to be discerned by
the naked eye, but which, with the aid
of a microscope are distinctly revealed.
Under the microscope, the shell
appears like sieve, or il
more closely resembles the white
perforated paper sold by stationers.
Through these holes there is constant
evaporation going on, so that an egg,
fromthe day that il is dropped by the hen
to the moment when it is consumed, is
losing weight and diminishing in vol
ume. This process goes on. much more
rapidly in hot weather than in cold,
and consequently perfect eggs are not
so readily procured in summer as in
winter. If, by any means, we stop this
eyaporative process, the egg remains
sound and good for great length of
time. Covering the shell with an i'm
pervioas varnish, or with mutton suet,
or lard, aids greatly in their preserva-
ton. The substance used TO stop trans
piration must not be soluble in watery
fluids, or liable to be readily removed.
BY chemical agencies, that is, by actu-
ally filling up the little holes in the shell
by lime placed in contact in solution
Qhe solution holding the proper ehemi-
cal substances 10 form an imperyious
coating of carbonate of lime over the
entire service), we have preserved eggs
for months, and even years. in a sweet
condition. Not long ago, eggs broken
in our laboratory were found TO be quite
fresh, which. according TO the memo
randum made upon the vessel, were
placed in the solution in May, 1867.
The shell of the egg is lined upon its
interior, everywhere, with very thin
but pretty tough membrane, which, di-
yiding at or very near the obtuse end,
forms small bag which is filled with
air. In new-laid eggs this folliele APP
pears very little, but it becomes larger
when the egg is kept. In breaking an
egg this membrane is removed with the
shell. TO which it adheres, and therefore
is regarded as part of it, which ii is
not.
The shell proper is made up mostly of
earthly materials, of which 81 per cent.
carbonate of lime. The remainder is
composed of two per cent. of animal
matter and one of phosphate of lime
and magnesia. Carbonate of lime is the
same material of which our marble
qnarries and chalk beds are composed;
it is lime, or oxide of calcium, combined
with carbonic acid, and is hard, insol-
uble mineral substance, which does not
appear to form any portion of the food
of fowls. Now, where does the hen
procure this substance with which TO
form the she'll? If we confine fowls in
a room and feed them with any of the
cereal grains, excluding all sand, dust
or earthly matter, they will go on for a
time and lay eggs, each one having a
perfect shell, made up of the same cal
carcous elements. Vauquelin, the dis
tinguished chemist, shut up hen ten
days. and fed her exclusively upon oats,
OF which she consumed 7,474 grains in |
weight. During this time four eggs
were laid, the shells OF which-weighed |
nearly 400 grains; of this amount 276 |
grains were carbonate of lime, II 1-2 |
phosphate of lime, and 10 gluten. But