breath through the tube and removing the mouth-piece a simple sentence can be loudly spoken, care being taken not to inhale without first restoring the mouth-piece. The tube is of sufficient length to communicate by one end with the outer air. A newly-emptied vat, of 1,000 barrels capacity, was selected for the scene of the experiment. Lighted candles, dipped one-eighth of an inch into the vat, were instantly extinguished without a flicker, thus showing that the air within was utterly irrespirable. The London agent of the patent, Mr. Applegarth, having put on the belt, and adjusted the mouth-piece and the eye-preservers, descended into the vat by a ladder, and, having reached the bottom, carried on a conversation with those outside, the tube serving as a speaking-trumpet.
Robert Hardwicke.—We have to record the death of Mr. Robert Hardwicke, the respected publisher, of London, which occurred on the 8th of March last, resulting from a stroke of paralysis with which he was seized a few weeks previously.
Mr. Hardwicke was well known by the number of useful hand-books on general science and natural history published by him at his house in Piccadilly; most of these works were beautifully illustrated, and sold at very moderate prices. But Mr. Hardwicke will be best remembered by his desire to popularize science. In this field he was an earnest and indefatigable worker, not from a wish to raise an army of pseudo-philosophers, but with the truest intention of elevating the standard of mental culture among all classes, and preparing the masses to follow and appreciate the work of those great minds who devote their lives to science.
In 1862 he started the Popular Science Review, a quarterly journal, and in 1865 issued Science Gossip, a charming little monthly, well illustrated, and sold for so small a sum as 4d. In 1869, under the heading of the Monthly Microscopical Journal, he undertook to publish the "Transactions of the Royal Microscopical Society," in conjunction with matter bearing on the same subject.
These ventures were highly creditable to the spirit and enterprise of Mr. Hardwicke, but were not so profitable as they deserved to be; they were, however, a success, and were continued up to the time of his death.
What Charles Knight was to general literature, Robert Hardwicke was to science. It was the aim of both to circulate in the homes of the people pure and readable matter, light and interesting, but worthy the perusal of reasoning beings. With Hardwicke, his work was a labor of love, for he thought that "the high prerogative of every advocate of scientific truth was not to plume himself upon his own successes, but to employ them for the good of others."
Carnivorous Plants.—The list of known carnivorous plants has been very considerably enlarged during the past year or two, many interesting additions having been made by sundry observers. To Mrs. Mary Treat is due the credit of having materially increased the fund of scientific knowledge with regard to this description of plants. We have already mentioned her observations on sundew, and now we have to recount her very full researches on the bladder-wort (Utricularia clandestina), a plant common in shallow ponds and swamps. This plant owes its vulgar name to the fact that its stem has attached to it numerous little bladders, the use of which has been supposed to be to float the plant. But they serve a different purpose. In December, 1874 the author placed some of these bladders under the microscope, and noticed a number of animalcules within. This discovery led to further researches during the following October. It was then found that the bladder consists of irregular cells, with clusters of star-like points (the office of which is still unknown), arranged very regularly over the inner surface. The animal most commonly seen entrapped in the bladder was a snake-like larva; but for a while the author was baffled in her efforts at finding out how the prey is taken. Soon, however, this difficulty was overcome, and the patience of the author was amply rewarded by a view of sundry animals entering into the maw of the utricularia.
One end of each bladder resembles a tunnel-net, open at the larger end and closed at the smaller. The animalcules
