Those not experienced in chemical manipulations may find some difficulty in obtaining and weighing accurately the several ingredients; and I should advise them to purchase the preparation sold by Mr. Bolton, of 146, Holborn Bars. This merely requires to be dissolved according to the instructions just given. Mr. Bolton has given minute attention to the preparation of the salts, and is now improving them by compounding with them the minute quantities of the more subtle ingredients, which were originally omitted by Mr. Gosse. The salts are sold in packets, at the rate of three gallons for a shilling; a price which must be considered reasonable when we consider the purity of the article, and the care taken in its manufacture.
Filtering.—When the salts are well mingled with the water, pass the liquid, through a filter, into the tank, which is supposed to have been already well-seasoned, and furished with a bottom of sand and pebbles, and any ornaments that may be deemed necessary. A bee glass, with a bit of sponge thrust into the orifice, is a convenient form of filter, but if such a thing is not at hand, take an old flower pot, and wash it quite clean, thrust a piece of sponge through the hole in the bottom, and throw into it a handful of powdered charcoal. This may be suspended above the tank, or stood on two slips of wood, and filled from time to time, till the whole of the water has been passed through it.
Some healthy plants of Ulva latissima and Enteromorpha compressa are now to be introduced, and the whole left undisturbed for at least a week or ten days, when the
