Immediately after the Franco-German war the value of ivory increased
considerably; and when we look at the prices realized on large Zanzibar
tusks at the public sales, we can well understand the motive power which
drove the Arab ivory hunters further and further into the country from
which the chief supply was derived when Dr. Livingstone met them.

In 1867 their price varied from £39 to £42.
" 1868 " " " " 39 " 42.
" 1869 " " " " 41 " 44.
" 1870 " " " " do. " do.
" 1871 " " " " do. " do.
" 1872 " " " " 58 " 61.
" 1873 " " " " 68 " 72.
" 1874 " " " " 53 " 58.

Single tusks vary in weight from 1 lb. to 165 lbs.: the average of a
pair of tusks may be put at 28 lbs., and therefore 44,000 elephants,
large and small, must be killed yearly to supply the ivory which _comes
to England alone_, and when we remember that an enormous quantity goes
to America, to India and China, for consumption there, and of which we
have no account, some faint notion may be formed of the destruction that
goes on amongst the herds of elephants.

Although naturalists distinguish only two living species of elephants,
viz. the African and the Asiatic, nevertheless there is a great
difference in the size, character, and colour of their tusks, which may
arise from variations in climate, soil, and food. The largest tusks are
yielded by the African elephant, and find their way hither from the port
of Zanzibar: they are noted for being opaque, soft or "mellow" to work,
and free from cracks or defects.