712 



THE POPULAR SCIENCE MONTHLY. 



a breathing-tube of an inch bore proceeding 

 downward, is firmly tied over the mouth and 

 nose. Dr. Kichardson carefully observed two 

 experiments, one of twenty minutes' length, 

 and another of an hour ; and was assured 

 by the diver that ' when under water he 

 breathed as freely and easily as in the air. 

 This was confirmed by his appearance and 

 condition at the end of the longest experi- 

 ment. He moved about on the floor of the 

 tank, picked up coins, and could lie down 

 and get up without difiiculty. The exact 

 mode by which breathing is effected Mr. 

 Fleuss declares to be extremely simple, 

 though it still remains a secret, but it is 

 wholly carried on within the apparatus, not 

 even the expired air becoming apparent in 

 the water. The facts demonstrate that, with- 

 out assistance from above, a man who has 

 had no previous experience of diving or re- 

 maining under water can take down with 

 him sufiicient oxygen to live there easily for 

 an hour ; and but for the cold the diver as- 

 serted that he could have remained another 

 hour and a quarter, and that he could easily 

 arrange to remain four hours. Depth he 

 said would make no difference as to breath- 

 ing within the apparatus. Dr. Richardson 

 is enthusiastic over the practical possibili- 

 ties of the discovery. If a man can thus 

 take his stock of breathing material with 

 him, and live for hours without external ac- 

 cess of air, he may extend the field of his 

 industries and investigations into the deep 

 sea, or the most rarefied atmospheres, into 

 mines filled with choke-damp, or amid the 

 suffocating smoke of conflagrations, without 

 fear of consequences. 



Saicide of the Scorpion.— The following 

 facts, as stated by Mr. Allen Thomson in 

 " Nature," throw some light on the mooted 

 question of the seK-destruction of scorpions. 

 He states that while residing at Lucca, in 

 Italy, he was greatly annoyed by the intru- 

 sion into the house of small black scor- 

 pions, which secreted themselves in bed- 

 clothing and articles of dress. Having 

 been informed by the natives that this ani- 

 mal would destroy itself if exposed to a sud- 

 den light, attempts were made to dispose of 

 the pest in the manner suggested. When 

 one was caught it was accordingly confined 

 under an inverted glass until evening, when 



the light of a candle was brought near it. 

 At this, the scorpion showed great excite- 

 ment, rushing round the glass with reckless 

 speed. This state lasted for a minute or 

 two, when the animal suddenly became quiet, 

 and turning his tail over its back brought 

 the recurved sting down upon the middle of 

 its head. Soon it became motionless, and 

 in fact dead. 



Electricity and Vegetation. — Several 

 months ago M. Grandcau and M. Leclerc 

 described to the Paris Academy experiments 

 on the influence of electricity on vegetation. 

 From these it appeared that flowering and 

 fructification are retarded whenever plants 

 are excluded from this agent. Recently M. 

 Naudin has been examining the subject, re- 

 peating the experiments of Grandeau and 

 Leclerc under different circumstances, and 

 with widely different results. He regards 

 the question as a complex one, and far 

 from being yet settled. The influence of 

 electricity on plants is probably modified 

 by the species, by climate, season, tempera- 

 ture, dry or wet weather, degree of light ; 

 possibly, also, by the geological and miner- 

 alogical structure of the ground. Until we 

 are better acquainted with these obscure 

 conditions of the problem, any conclusion 

 applied to the whole of the vegetable king- 

 dom is premature, 



Transmissibility of Human Rabies.— 



Whether hydrophobia can be transmitted 

 from man to man, or from man to the low- 

 er animals, has long been a- disputed ques- 

 tion, with little scientific evidence on either 

 side ; some recent observations, however, 

 by M. Raynaud, in the Lariboisiere Hos- 

 pital, in Paris, would seem sufficiently con- 

 clusive to put an end to all uncertainty on 

 the subject. A man was brought to the 

 hospital suffering from rabies, having been 

 bitten by a dog on the lip forty days before. 

 The wound was cauterized two hours after 

 it was made, and no serious apprehensions 

 were felt about the result until a few days 

 before he entered the hospital, when the 

 usual symptoms of hydrophobia appeared. 

 The day before his death, in a quiet inter- 

 val, he yielded with the best grace to ex- 

 periments in inoculation which were made 

 with his blood and his saliva. The result 



