We do not know how the idea originated that plants do not grow in the dark, though the idea seems widely prevalent in Europe. In America it has been proved that Indian corn grows more rapidly by night than by day. In American cellars potatoes sprout, and all kinds of vegetables grow to our aggravation, if there is any heat much above the freezing point. True they require light to make a green growth, but the actual rapidity of growth is at least the same. It does not seem to be true in England, however, where they are much exercised over Dr. Siemen's experiments with the electric light. The doctor has a large forcing-house, in which are many kinds of fruits and vegetables which mature during the winter. There has to be a steam engine to make the electricity which gives the light; and the waste steam from the engine, condensed, gives hot water, by which the temperature is kept at 60 degrees.

So far as we have been able to gather from Dr. Siemen's experiments, they are not comparative. The electric light was kept all night in his forcing-house, and under this perpetual brightness by night and by day, the crops were wonderfully productive and remarkably satisfactory. This is all the experiments amount to. There was not another house just alike, and under the management of the same excellent gardener, to show how much better the lighted house was.

So far as the electric light on the growth of plants is concerned, we do not feel that it will be of great value in our culture, not only because plants grow as well in the dark, but because the means of communication between the tropical and the arctic portions of our country are so perfect that we can have the rarest summer fruits and vegetables on our tables while zero winds are blowing on our homes. Forcing-houses are not as popular as in the old world. But there is great value to us in Dr. Siemen's experiments as showing how the introduction of the electric light may be made use of in heating greenhouses. As a general rule it will not pay to buy and run a steam engine for lighting our country homes instead of gas or oil; but if at the same time we can heat our greenhouses with the waste steam, or make the engine useful in other things, it may come into general use.