440 Prof. E. Wartmann's Seventh Memoir on Induction. 



and France* have taken part in these researches, which have 

 recently been renewed and much extended by M. Boutignyf. 



179. I propose to examine in this memoir the relations of 

 the electric fluid with the spheroidal state, — relations which 

 appear to me not to have hitherto attracted the attention of 

 observers. In the face of incomplete and often contradictory 

 theories, by which this singular condition of bodies is attempted 

 to be explained, it is necessary to accumulate new facts in order 

 to determine with certainty the part taken by the different 

 forces which produce it. 



180. My first experiments were made with electricity of 

 tension. The apparatus employed is very simple. It consists 

 of a support furnished with a moveable stem terminated by a 

 ring, on which rests a tolerably thick platina crucible, almost 

 flat, and of a diameter of m, 06. Another support carries, at 

 the extremity of a metallic arm, a platina wire twisted on itself, 

 and which bends back below in a sort of eye, or elongated 

 slightly open loop, to m 001 of the capsule. A chain attached 

 to the arm serves to connect this wire with the external arma- 

 ture of a Leyden jar. 



181. After heating the capsule, some portions of liquid are 

 projected on to it, which collect in a spheroidalized drop around 

 the eye. The lamp is then taken away, and the knob of the 

 jar well-charged is rapidly approached to the lower surface of 

 the crucible. The explosion determines different effects, ac- 

 cording to the nature of the liquid and the temperature of the 

 vessel containing it. 



182. Let us first raise the capsule to a degree of heat which 

 much exceeds the limit indispensable to the spheroidal state. 

 If we operate on pure water, this is not traversed by the dis- 

 charge, and its close or radiating form experiences no altera- 

 tion. The spark, of a purplish colour, does not penetrate the 

 immersed portion of the platina wire, but glides over the con- 

 vex surface of the drop. 



Fisica di Pavia, 1816, p. 255 ; Giornale delV I. R. Islituto Lombardo delle 

 Scienze, Lettere ed Arti, e Biblioteca Italiana, 1844, p. 193. — Belli, Co?'so di 

 Fisica, vol. i. p. 96. — Belli e de Kramer, Giornale dell' I. R. Istituto Lom- 

 bardo, 1844, p. 192. 



* Lambert, Pyrometrie, p. 130. — Rumford, Mcmoircs surla Chaleicr,p. 93. 

 — Pouillet, Annates de Chimieet de Physique, vol. xxxvi.p.5. — Beaudrimont, 

 Ann. de Chim. et de Phys., vol. lxi. p. 319. — Laurent, Ann. de Chim. et de 

 Phys., vol. Ixii. p. 327. — Le Clievallier, Journal de Chimie Medicate, vol. vi. 

 p. 539 ; and Journal de Pharmacie, vol. xvi. p. 666. — Dulong, Journal de 

 Pharmacie, 1830. — Pelouze, Journal de Pharmacie, 1840, p. 7/9. — Dumas, 

 Traite de Chimie appliquee aux Arts, vol. i. p. 32. — Person, Comptes Rendus, 

 vol. xv. p. 492. 



f Noavelle branche de Physique, ou etudes sur les corps a I'etat spheroidal. 

 2nd edition. Paris, 1847. 



