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The mesogloea in the hydropolyp is a thin
elastic layer, in which may be lodged the
muscular fibres and ganglion cells mentioned above, but which never contains any
connective tissue or skeletogenous cells or any other
kind of special mesogloeal
corpuscles.
The envelope is double, consisting of an external chitinous stratified shell, and an
internal thin
elastic membrane.
In his eighteenth year, while still a student in Edinburgh, he contributed two valuable
papers to the Transactions of the same society - one of which, " On the Equilibrium
of
Elastic Solids," is remarkable, not only on account of its intrinsic power and the
youth of its author, but also because in it he laid the foundation of one of the most
singular discoveries of his later life, the temporary double refraction produced in
viscous liquids by shearing stress.
In such cases the contact of an insect or other body with those processes is sufficient
to liberate the pollen often with
elastic force, even when the anther itself is not
touched.
Elastic web weaving by power looms is
carried on to a great extent, and the
manufacture of lace and net curtains, gimp trimmings, braids and cords.
Elaborate
regulations were in force, but no one knows how
elastic they were in
practice.
The wood is strong, light and very
elastic, forming an excellent material for small
masts and spars, for which purpose
the trunks are used in America, and exported
largely to England.
Between 1882 and 1889 a series of papers on certain points in the electromagnetic
theory of light and its relation to the various
elastic solid theories appeared in the
American Journal of Science, and his last work, Elementary Principles in Statistical
Mechanics, was issued in 1902.
That it is
elastic, with narrow limits, is proved by its clear ring when struck with a
hard body in circumstances permitting of free vibration.
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