Bergmehl

Bergmehl, or MOUNTAIN-FLOUR, is a recent deposit of a white or cream-coloured powder of extreme fineness, composed almost entirely of the indestructible siliceous frustules or cell-walls of Diatomaceæ (q.v.). From its resemblance to flour, it has been mixed with ordinary food in seasons of scarcity, and thus used by the inhabitants of Norway and Sweden, who suppose it to be nutritious. When subjected to a red heat, it loses from a quarter to a third of its weight, the loss consisting probably of organic matter, and this would make it in itself nutritious; but it seems to derive its chief value from its increasing the bulk of the food, and rendering the really nutritious portion more satisfying. On the other hand, some experiments tend to show that bergmehl does contain a very small proportion—3 or 4 per cent.—of positive nutriment. Similar deposits occur at Dolgelly in North Wales, at South Mourne in Ireland, and in Mull, Raasay, Skye, and elsewhere in Scotland. The contained organisms show that these beds have been deposited in fresh water.