Page:A Treatise on Electricity and Magnetism - Volume 2.djvu/454

 422 ELECTRIC 'IIIEDHY OF mrow/1*1SlL [839. Thu moguulic moment af the eimvet in the product ol` its etmngdi lg lhs arm ot' the circuit, or yu, and the mwlvonl part ui this in the dlractiun of the iuagnutizing iowa ix yi} our 0, or, hy (S), ¤ - # sm a, (M) lf them are u such mnlseulns in nnitaf volume, and if their axes nin distritnxtnd inditforeiitly in all directions, than the avuznga vsluc of eo¤’0 will hs Q, and tha intensity of magnetization of tho sabslnnes will he 1# (7) Neumann; couliicieut r»l'mngar:ti.uhl¤n is therefore wil s - Mg T - wt Thu inngimtimtion ol' the sulxstanu is therefore iu the opposite tlireeticn to the magnetiziug A`or¤s_,or, in other wnnls, the sulmannn is rlinmzgnutie. It is also exactly proportional to the ningautizing fame, and llocs not will to it linits limit., as iu the casa uf ordinary magnetic indizctiun, Sse Arts. M2, Sac. E39.] It tho directions af the axes ul' the mcleeular channels ara nrinngerl, not inrliii`ei·eatly in all diieelions, but with n pi·epanrlt·i»- ating numbor in certain directions, than thu sum s  we it extended to all the molnsules will have tliflhmni: values aceording tu the dirautiou of the line from which 0 is mcasumnl, and the Aim trihutiou of Lhnsc values in dillbrent ilirootians will hu similar to tho distrilzation of the values of moments el' inertia nhoub nm: in dif. fsmnf. directions through the same paint, Such in distribution will explain the magnetic plienomann related to axes in the body, described by Pltiokor, which Faraday has collorl Magracrystollis plisaoinaim. See Art. U5. 840,] Let us naw consider whnt would lm the effect, it inawnrl ol' the eluetiiu current being cantinell to it certain channel within thc molecule, the whale molecule wm snppnretl a parfeet eemluemr. Lot us Login with tho earn of n lmdy the Form of which is ncyclie, that is tn any, which is not in the ibrm of a ring; or peifuiatcll body, and lot us suppose that this livxly is cveryxvlierc surrenndul by u thin shall of pcri"¤¤tl_v ouxidaoting matter. l We have proved in Art, GM, that a closed sheet of perfectly l canrlueting matter of any {`urm, originally free hom enrrunts, he· `