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THE POPULAR SCIENCE MONTHLY 



breath tlirough the tube and removing the 

 mouth-piece a simple sentence can be loudly 

 spoken, care being taken not to inhale with- 

 out 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 extin- 

 guished without a flicker, thus showing 

 that the air within was utterly irrespirable. 

 The London agent of the patent, Mr. Apple- 

 garth, 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 Hardwicko. We have to record 

 the death of Mr. Robert Hardwicke, the 

 respected publisher, of London, which oc- 

 curred 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 sci- 

 ence. 



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 ilicroscopical Jour- 

 nal, he undertook to publish the " Trans- 

 actions 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. Hard- 



wicke, but were not so profitable as they 

 deserved to be ; they were, however, a suc- 

 cess, and were continued up to the time of 

 his death. 



What Charles Knight was to general 

 literature, Robert Hardwicke was to sci- 

 ence. It was the aim of both to circulate 

 in the homes of the people pure and reada- 

 ble matter, light and interesting, but worthy 

 the perusal of reasoning beings. With Hard- 

 wicke, 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 era- 

 ploy them for the good of others." 



Carnivorons Plants. The list of known 

 carnivorous plants has been very consid- 

 erably 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 {UiricvJaria 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 diff'erent purpose. In December, 

 1874 the author placed some of these blad- 

 ders under the microscope, and noticed a 

 number of animalcules within. This dis- 

 covery 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 ani- 

 mal most commonly seen entrapped in the 

 bladder was a snake-like larva ; but for a 

 while the author was baSled in her effijrts 

 at finding out how the prey is taken. Soon, 

 however, this difficulty was overcome, and 

 the patience of the author was amply re- 

 warded by a view of sundry animals enter- 

 ing 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 



