new; I knew an instance in which a consignment of animals was lost, from no traceable cause, except that the water-cask, which was quite new, had been stopped with a bung, which had been previously used in a jar of some chemical solution; yet the bung had been, as was supposed, thoroughly soaked and cleansed. If a cask of fir-wood can be procured it is preferable: the wood of the oak, of which wine-casks are usually made, gives out tannin or gallic acid, to the contained water, which by its astringency converts the animal integuments into leather; if the water on coming out of the cask has a brown tinge, without interfering with its transparency, this is suspicious. If you cannot get any other than an oak cask, let it be well seasoned for two or three weeks before it be used, by filling it with water (fresh or salt), changed every day.
For smaller quantities of water large jars of stoneware are the best, being free from every objection arising from liability to taint or tinge. Both casks and jars can be easily sent by railway to any part of the kingdom; and pure water will not spoil by delay.
THE STOCK.
I have already entered into particulars concerning the modes of collecting both plants and animals, and need not repeat what may be found in the early pages of this volume. A few additional observations, however, occur to me.
Plants.—What are the most suitable plants for an Aquarium? Not the Oar-weeds or Tangles (Laminaria); for though young specimens have an attrac-
