Otters and beavers that run dark in the hair or wool are more valuable than the paler ones, the wools of which are frequently touched with a chemical to produce a golden shade.
It is the chief town of a wide district exporting olive oil, esparto', corn and flour, wools and Algerian onyx; and has a population of (1906) 24,060.
After being unhaired the darkest wools are the most valuable, although many people prefer the bright, lighter brown tones.
The colours of the under wools of river otters vary, some being very dark, others almost yellow.
Many of the domestic kind in central and northern Europe and Canada are used for drivers' and peasants' coat linings, &c. In Great Britain many coats of the home-reared sheep, having wools two and a half to five inches long, are dyed various colours and used as floor rugs.