With regard to shape, they should have a comparatively long
oval shell, one end of which is blunt and the other, a sharp curve.
[Illustration: FIG. 2: Internal structure of egg.]
[Illustration: FIG. 3: FRESH, 3 WEEKS, 3 MONTHS, OLDER.]
20. JUDGING THE QUALITY OF EGGS IN THE HOME.--After eggs have been
received in the home, several simple tests for determining their
freshness can be applied in addition to the ones already mentioned. A
rather indefinite test, but one that is sometimes applied to determine
the freshness of an egg, is to shake it. However, to be able to carry
out this test successfully, it is well to understand the interior
structure of an egg. Fig. 2 illustrates this clearly. At _a_ is shown
the air space previously mentioned; at _b_, the spiral cords that run
from the yolk to each end of the egg and hold the yolk in place; at _c_,
the yolk; and at _d_, the white. When the water inside the shell
evaporates, the yolk and white shrink so much that they can be felt
moving from side to side when the egg is shaken. The staler the egg, the
more pronounced does the movement become. This method should be applied
only immediately before the egg is to be used, as the thin membrane
between the yolk and the white and the spiral cords that hold up the
yolk are liable to be disturbed by the shaking. If they are broken, the
yolk will settle and finally adhere to the shell in case the egg is
stored for any length of time after that.
[Illustration: FIG.
Pages:
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117