Electricity. — Magnetim. 371 



same apparatus, M. Becquerel has discovered that an electrical current 

 goes from the acid to the water, when sponge of platinum, that has im- 

 bibed distilled water, is plunged into the dish of platinum containing 

 hydrochloric acid. 



In order to observe the electricity of solutions of alkalis in water, he 

 fixed in the platina pincers a fragment of hydrate of potash or soda, en- 

 veloped in papier Joseph, and then plunged it into distilled water in 

 the platina cup. A current was thus produced from the water to the 

 alkali. 



M. Becquerel also found that electricity was developed during the mix- 

 ture of sulphuric and nitric acids. Bull, des Sc. Phys. &c. Fev. 182-i, p. 99. 



12. Electrical Gale. — On the 6th December 1923, about 100 miles to the 

 west of the Fiord of Drontheim, the Griper, commanded by Captain 

 Clavering, experienced a severe gale which lasted three days, and during 

 which period there was no intermission of its violence. This gale was re- 

 markable for the small amount of the effect produced on the barometer, 

 either on its approach, during its continuance, or on its cessation ; and by 

 the indications which were afforded of its having originated in a disturbed 

 state of electricity] in the atmosphere. It was accompanied by very vivid 

 lightning, which is particularly unusual in high latitudes in winter, and 

 by the frequent appearance, and continuance for several minutes at a 

 time, of balls of fire at the yard-arms and mast-heads. Of these, not less 

 than eight were counted at one time. Sabine's Pendulum Experiments. 

 p. 181. 



MAGNETISM. 



13. Mr Babbage and Mr Herschel on the Magnetism developed during 

 Rotation. In our last number, we gave a notice of the experiments made in 

 France on the effect of copper in motion or at rest, on magnetic needles. 

 Mr Babbage and Mr Herschel have pursued the subject with much suc- 

 cess, and have communicated an account of their experiments to the Royal 

 Society. In order to reverse the experiment, they put in rotation a power- 

 ful horse shoe magnet, and suspended over it various metals and other sub- 

 stances. In this way they developed signs of magnetism in copper, zinc, sil- 

 ver, tin, lead, antimony, mercury, gold, bismuth, and carbon, in tbatmetal- 

 loidal state in which it is precipitated from carburetted hydrogen gas works. 

 In sulphuric acid, rosin, glass, and other non-conductors, or imperfect 

 conductors of electricity, no positive evidence of magnetism was obtained. 



In order to determine the comparative intensities of these bodies, Messrs 

 Babbage and Herschel used two methods, 1st, By observing the deviation 

 produced in the needle by plates of great size cast to one pattern ; and, 

 2dly, By observing the times of rotation of a neutralized system of mag- 

 nets suspended over them. These two methods assigned the same order 

 to all the bodies but copper and zinc ; and it is a very curious fact, which 

 the authors have no doubt thoroughly investigated, that the two methods 



