an ounce of solid waste each day while it takes a tube 30 feet long, with
millions of glands, to deal with a sip of milk.

Man's finest steam engine turns one-eighth of the energy supplied into
work; nature's engine, muscle, turns one-third into work. The body contains
9 gallons of water, enough carbon to make 9,000 lead pencils, phosphorus
for 8,000 boxes of matches, iron for 5 tacks, and salt enough to fill half
a dozen salt-cellars.

Over 40 food-ferments have been found in the liver; there are 5,000,000 red
and 30,000 white blood corpuscles in a space as big as a pin's head, each
one of which travels a mile a day and lives but a fortnight, millions of
new ones being built up in the bone-marrow every second; a flash of light
lasting only one eight-millionth of a second, will stimulate the eye, which
can discriminate half a million tints. The ear can distinguish 11,000
tones, and is so sensitive that we hear waves of air less than one
sixty-thousandth of an inch long; a mass of almost liquid jelly--for 81 per
cent of the brain is water, and Aristotle thought it was a wet sponge to
cool the hot heart--sends out impulses ordering our every thought and act,
and stores up memory, we know not how or where.

There are 10,000,000,000 of cells in the brain cortex alone, and 560,000
fibres pass from the brain down the spinal cord.

A clear, watery cell, no larger than the dot on an "i" encloses factors
causing genius or stupidity, honesty or roguery, pride or humility,
patience or impulsiveness, coldness or ardour, tallness or shortness, form
of head or hands, colour of eyes and hair, male or female sex, and the
thousand details that make a man.