ELECTRICITY. 



243 



Rhubarb (tincture) ......... . Sugar-loaf). 



Starch-caramel I'.'.!!!!!'.!'.!! 

 Gum-caramel 



S 

 Gum 



toSSSSatib. ................ iSroot. 



Onion ...................... " 



Horseradish ................ Table salt. 



Pepper (white)'.'. '.'.'. '.'.'. ".'.". ".'.'. 



Mustard ...... !!'.'.'.!'.'.'.!'.'.'.! Tartaric acid. 



Cayenne 'pepper! I!.'.".'!.'.'' 

 Pepper (white) . . . . . . . . . . 



Tea^(black) 



Quinine (Howard's) .'.'.'.. 

 Gentian-root ........ .'..'.. 



Horeh n oS e :*.:;:'.::":'.'. 

 Lavender- water .'.'.'.'.'.'!.'.' 



$e a8 l i rmiAt 



Raw'potato '. '.'. ' . . ." i . .* .' . ." ' . . . Lemon juice. 



Rind of lemon .............. | 



caSShor (tincture) .' '. '. '. '. '. '. '. '. 

 Laudanum .................. " 



Peravtanbfr'k 6 '*::"':::':::: Dilute tt sul P huric * cid - 

 Quinine (Howard's). ..!!!!!. " " 



i^ejtincture) ............ Turpentine. 



starch.^ " 



starch ............... .' ..... '. iodine (tincture). 



Caustic potash .............. NeatVfoot oil. 



It is somewhat difficult to eliminate from these ex 

 eriments all error arisin from difference of temer 



upon to the same temperature before testing them ; 

 otherwise a thermo-electric current from the hotter 

 to the colder liquid may affect the needle, and mask 



' 8 &r a3 



Accumulated Magnetic Power. Experi- 

 ments recently made by M. Jamin prove that 

 magnetic power may, like electricity, be accu- 

 mulated. The author had a large horseshoe 

 magnet made, consisting of ten lamina^ of per- 

 fectly homogeneous steel, each weighing ten 

 kilogrammes. This magnet he suspended to a 

 hook attached to a strong beam, and, having 

 wound copper round each of the legs, which 

 were turned downward, he put the latter into 

 communication with a battery of fifty of Bun- 

 sen's elements, by which means the horseshoe 

 might be magnetized either positively or nega- 

 tiveh- at pleasure The variations 4re fa 

 cated by a small horizontal needle situated in 

 the plane of the poles. There was, further, 

 a series of iron plates, which could be sepa- 

 rately applied to each of the lamina. Before 

 attaching any of the latter, the electric current 

 was driven through the apparatus for a few 

 minutes, and then interrupted, whereby the 

 magnet acquired its first degree of saturation, 



mflrTrpfl hv n pertain (Wift?rm nf ^ a T^/nJ 

 marKea Dy a certain deviation oi the needle. 



One of the iron plates (usually called "con- 

 tacts ") was put on, and supported a weight of 

 140 kilogrammes. The current having passed 

 through again a few seconds, it was found 



fhif tliA "hmapTinA -wrmil^ onvvnA^f QHA v?i^ 

 ,nat tue noisesnoe would support 300 kilo- 



grammes. Ine number ot contacts was then 



increased to five, which together, in the natu- 

 ral gtate? SU pp Or ted 120 kilogrammes, but, after 

 the passage of the current, they sustained 680 

 kilogrammes, and continued to do so for a full 

 >ek. ^o sooner, however, were the contacts 

 taken off, than the horseshoe returned to its 

 usual Permanent strength of 140 kilogrammes. 

 This tends to show that magnetism may be 

 condensed, like electricity, for a short period. 



Magnetism and the Casting of Iron. M. 

 Treves has recently experimented to ascertain 

 the effect of magnetism upon the casting of 

 iron. Two small moulds were made to receive 

 equal quantities of precisely similar molten 

 iron, but under different conditions; one was 

 placed so as to be entirely removed from any 

 magnetic influence, while the other was placed 

 in the axis of a powerful electro-magnet, ac- 

 tuated by twelve of Bunsen's elements. The 

 moulds were filled with the molten metal, and, 

 after they had cooled, the two moulds were 

 broken up, when no difference was observed in 

 the crystallization of the iron, but the iron ex- 

 posed to the magnetic influence had become 

 magnetic, and it remained feebly so. 



Electro-capillary Actions. In his sixth me- 

 moir on electro-capillary actions, M. Becquerel 

 describes a process for obtaining a great num- 

 ber of hvdrated oxides in the crys t a lline state. 

 In a vessel containing a solution of nitrate of 

 copper, a smaller vessel, one side of which was 

 W* <? P-hment-paper, was. placed 

 containing alummate of potash. Nitrate of 

 potash was produced, but in the place of alu- 

 minate of copper; in the porous vessel crystals 

 of hydratedaTaminapresLted themselves, and 

 on the outside crystals of hydrated oxide of 

 copper formed. By replacing the alummate 

 o f potash by silicates, M. Becquerel obtained 

 hydrated silica sufficiently hard to scratch glass. 



Experiments with a Great Induction Coil. 

 Mr. J. H. Pepper details in the London Chemi- 

 cal News some remarkable experiments made 

 with the great induction coil at the Eoyal 

 Polytechnic, London. The following are ex- 

 tracts from his papers: 



T he length of the coil from end to end is 9 feet 10 

 inches, and the diameter 2 feet ; the whole is cased 

 in ebonite ; it stands on two strong pillars covered 

 ite > *** of P illars * e ' m diameter 



The total weight of the great coil is 15 cwt., that 

 of the ebonite alone being 477 Ibs. 

 The primary wire is .made of copper, of the highest 



Sf^flSA ^inch, anci fflSSftKS 

 yards . The num ber of revolutions of the primary 

 wire round the core of soft iron is 6,000, its arrange- 

 ment being 3, 6, and 12 strands. 

 ^ The total resistance of the primary w 2,201,400 

 British Association units, and the resistances of 

 the primarv conductors are respectively-for three 

 stran p ds , 0.733800 B. A. U. ; sixf 0.366945 B.A.U; 

 twelve, 0.1834725 B. A. U. 



The primary core consists of extremely soft straight 

 iron wires, 3 feet in length, and each wire is 0.0625 of 

 an inch in diameter. The diameter of the combined 

 W i res is 4 inches, and the weight of the core is 123 fbs. 



The secondary wire is 150 miles in length; it is 



