-147.
bent rays, 113, 114.
chemical action, 126-127.
disease, 131-132.
essential to life, 131, 132.
fading illumination, 105, 106.
influence on color, 134.
reflection of, 109-112.
refraction of, 113-125.
travels in a straight line, 108.
white, composed of colors, 134.

Lighting, artificial, 148-153.

Lime, chloride of, 240, 251.

Limewater, 220.
and carbon dioxide, 228.

Linen, bleaching, 241.
dyeing, 245-247.

Lines, of force, 329-331, 334.
isobaric, 88, 91.
isothermal, 89, 91.

Liquefaction of gases, 97, 98.

Liquid air, 98.

Liquid soap, 223, 224.

Litmus, action of acids, 220.
action of bases, 221, 222.
action of neutral substance, 222.

Logwood dyes, 245, 247, 248.

Los Angeles aqueduct, 211.

Lye, 221, 222.

Machines, compound, 171.
inclined plane, 162-166.
lever, 158-162.
pulley, 166-169.
wheel and axle, 169-171.

Madder, for dyes, 245.

Magnet, 328.
electro-, 319.
field of, 329-331.
lines of force about, 329-331.
poles of, 330-332.
properties of electricity, 318.

Magnetic, needle, 328.
poles, 329-331.

Magnifying power, of a lens, 115.
of a microscope, 115.
of a telescope, 115.

Mammoth Cave of Kentucky, 71.

Manganese dioxide, 46.
chlorine made from, 238.
oxygen made from, 46.

Marble, for carbon dioxide, 55.

Matches, 47.
safety, 47-48.

Matching colors, 137.

Matter, conservation of, 58, 59.

Meat, 66.
preservation of, 253.

Mechanical devices, 154, 155.

Melting, 39, 40.

Melting point, 40.

Melting substances without a definite melting point, 40.

Mercerized cotton, 218.

Mercury, barometer, 84.
thermometer, 14-17.

Metals, electroplating, 317.
preservation by paint, 253-254.
veins deposited by precipitation, 72, 73.
welding, 315.

Meter, gas, 93, 94.

Microoerganisms, 132, 133.

Microscope, 115.

Milk, boiling point, 32.
Pasteurized, 250.

Minerals, in foods, 62, 63.
in water, 70, 71.

Mirrors, 108-112.
distance of image behind mirror, 111.
distance of object in front of mirror, 111.
image a duplicate of object. 111.

Molding of glass