Verily, and in conclusion, we declare that it is a libel upon the birds to say that they build their nests guided only by that nameless tendency signified by the common acceptation of the term “instinct.”
The humblest creature God has made
Fulfills some noble, wise design;
And, dowered rich with reason’s aid,
It boasts a lineage divine.
L. P. Veneen.
BERYL.
This mineral species includes a number of varieties which are highly valued as gems. These are, besides Beryl itself, the gems emerald, aquamarine and golden beryl. Chrysoberyl, it may be noted, is not a variety of Beryl, but a distinct species.
While these gems all differ in color, they are the same mineral and are practically identical in composition, hardness and other properties. In composition they are a silicate of aluminum and glucinum, the percentage being, for normal beryl, 67 per cent of silica, 19 per cent of alumina and 14 per cent of glucina.
The beautiful green color of the emerald is probably due to a small quantity of chromium which it usually contains, though some authorities believe organic matter to be the coloring ingredient. To what substance the other varieties of the species owe their color is not known.