Fibers

Figure A shows cotton fibers which are smooth on the surface, where as figure B shows woolen fibers that are covered with scales.

Alexander Smith, Intermediate Text Book of Chemistry (New York: The Century Co, 1920) 2

2400×1509, 308.0 KiB

1024×643, 54.6 KiB

640×402, 31.1 KiB

320×201, 12.8 KiB