1866.] Mr. Wilde — Researches in Magnetism and Electricity, 107 



the U. hemitoechus of Dr. Falconer. It is defined as **R. a narines demi- 

 cloisonuees," and is probably not the same animal as the R. leiHorhinus 

 or " i2. d narines 7ion-cloisonnees'' of Baron Cuvier, the evidence as to 

 the absence or presence of the cloison in the type of the species being of 

 the most conflicting nature. In Central France it is identical with R. me- 

 sotrojius and B. velaunus of M. Aymard, the R. Aymardi of M. Pomel, 

 and the R. leptorhimis (du Puy) of M. Gervaise. Its dentition is charac- 

 terized by the presence of the third costa in the upper molar series, 

 coupled with the stoutness of the cingulum, the suppression of the ante- 

 rior combing plate, the smoothness of the enamel, and the extent to which 

 the upper molars overhang the lower, which causes the enamel on the 

 outer side of the latter to be worn obliquely. The lower molars can be 

 determined by the flattening of the anterior area, coupled with the fine 

 sculpturing of the enamel- surface. In common with the other fossil 

 British Rhinoceroses, it possessed a molar series of six only on either side, 

 and was bicorn. It ranged through England, from the Hyeena-den of 

 Kirkdale in Yorkshire in the north, as far south as the plains of Somer- 

 setshire, and as far to the West as Pembrokeshire. It is very generally 

 found in association with Elephas a?itiquus and Hippopotamus majors 

 both species which lived in Pliocene times. The association in Wookey 

 Hole Hyaena-den with Elephas p-imigenius and R. tichorhinus and other 

 characteristic Postglacial mammals proves that it coexisted with the 

 tichorhine species, to which it probably bore the same geographical rela- 

 tion as the Elk does to the Reindeer in the high northern latitudes. The 

 sum of the evidence proves that it was coeval with the Mammoth and 

 tichorhine Rhinoceros, and does not characterize deposits of an earlier 

 epoch in the Pleistocene. It has not as yet been found in Preglacial for- 

 mations. The R. leptorhinus is more closely allied to the bicorn Rhino- 

 ceros of Sumatra than to any other living species. 



II. ^' Experimental Researches in Magnetism and Electricity/^ — 

 Part I. By H. Wilde, Esq. Commuuicated by Mr. Faraday. 

 Received March 26, 1866. 



(Abstract.) 



This paper is divided into two sections, — the first being on some new 

 and paradoxical phenomena in electro-magnetic induction, and its relation to 

 the principle of the conservation of physical force ; the second on a new and 

 powerful generator of dynamic electricity. 



The author defines the principle of the conservation of force to be the 

 definite quantitative relation existing between all phenomena whatsoever; 

 and in the particular application of the principle to the advancement of 

 physical science and the mechanical arts, certain problems are pointed out 

 which, in their solution, bring out results as surprising as they are para- 

 doxical. Although, when rightly interpreted, the results obtained are in 



