sea affects a round figure by the mutual
attraction of its parts by gravity."

In a letter to Mr. Boyle (1678-79) Newton explains his views respecting
the ether. He considers that the ether accounts for the refraction of
light, the cohesion of two polished pieces of metal in an exhausted
receiver, the adhesion of quick-silver to glass tubes, the cohesion of
the parts of all bodies, the phenomena of filtration and of capillary
attraction, the action of menstrua on bodies, the transmutation of gross
compact substances into aerial ones, and gravity. If a body is either
heated or loses its heat when placed in vacuo, he ascribes the
conveyance of the heat in both cases "to the vibration of a much subtler
medium than air"; and he considers this medium also the medium by which
light is refracted and reflected, and by whose vibrations light
communicates heat to bodies and is put into fits of easy reflection and
transmission. Light, Newton regards as a peculiar substance composed of
heterogeneous particles thrown off with great velocity in all directions
from luminous bodies, and he supposes that these particles while passing
through the ether excite in it vibrations, or pulses, which accelerate
or retard the particles of light, and thus throw them into alternate
"fits of easy reflection and transmission." He computes the elasticity
of the ether to be 490,000,000,000 times greater than air in proportion
to its density.

In 1722, in his eightieth year, Newton began to suffer from stone; but
by means of a strict regimen and other precautions he was enabled to
alleviate the complaint, and to procure long intervals of ease. But a
journey to London on February 28, 1727, to preside at a meeting of the
Royal Society greatly aggravated the complaint. On Wednesday, March 15,
he appeared to be somewhat better. On Saturday morning he carried on a
pretty long conversation with Dr. Mead; but at six o'clock the same
evening he became insensible, and continued in that state until Monday,
the 20th, when he expired, without pain, between one and two o'clock in
the morning, in the eighty-fifth year of his age.

* * * * *

JOHN BUNYAN

Grace Abounding

During his life of sixty years Bunyan wrote sixty books, and
of all these undoubtedly the most popular are the "Pilgrim's
Progress," "The Holy War," and "Grace Abounding." His "Grace
Abounding to the Chief of Sinners," generally cal