32 



CANADA IN 1852. 



[1852. 



off this relation except b}" traiisfevniig the forces of these surfaces 

 to equal amounts of the contrary forces provided elsewhere. 

 Another limitation is, that the power is definite in amount. If 

 a ball a be ohai-ged with 10 of positise electricity it may be made 

 to act with that amoiuit of power on another ball b charged with 

 10 of negati\-e electricity ; but if 5 of its power be taken up by 

 a third ball c charged with negative electricity, then it cau only 

 act with 5 of power on ball a, and that ball must find or evolve 5 

 of positive power elsewhere : this is quite uidike what occm-s 

 with gi-avity, a power that presents us with notiiing dual in its 

 character. Finally, the electric force acts in curved" Unes. If a 

 ball be electrified positively and insulated in the air, and a round 

 metalhc plate be placed about 12 or 15 inches oft) facing it, and 

 uninsulated, the latter will be found, by the necessity mentioned 

 above, in a negative condition ; but it is not negative" only on the 

 side facing the ball, but on the other or outer face also, as may 

 be shown by a carrier applied there, or by a strip of gold or sil- 

 ver ]e;if hung against that outer face. Now, the power aftecting 

 this fiice does not pass through the uninsulated plate, for the 

 thinnest gold leaf is able to stop the inductive action, but round 

 the edges of the face and therefore acts in curved lines. All 

 these pioints indicate the existence of physical lines of electric 

 force : — the absolutely essential relation of positi\'e and negati\-e 

 surfaces to each other, and their dependence on each other con- 

 trasted with the known mobility of the forces, admit of no other 

 conclusion. The action also in cm-ved lines must depend upon 

 a physical line of force. And there is a third important charac- 

 ter of the force leading to the same result, namel}-, its affection 

 by media having different specific inductive capacities. When 

 we pass to dynamic electricity, the evidence of physical lines of 

 force is far more patent. A voltaic battery having its extremities 

 connected by a conducting medium, has what has been expressly 

 called a current of force nmning round the circuit, but this current 

 is an axis of power having equal and contrary forces in opposite 

 directions. It consists of lines of force which are compressed or 

 expanded according to the transve^e action of the conductor, 

 which changes in direction with the form of the conductor, 

 which are found in every part of the conduotor, and can 

 be taken out fi-om any place by channels properly appointed 

 for the purpose ; and nobody doubts that they are physical lines 

 of force. Finally as regards a magnet, which is the object of the 

 present discourse. A magnet presents a system of forces perfect 

 in itself, and able, thei-efore, to exist by its own mutual relations. 

 It has the dual and antithetic character belonging to both static and 

 dynamic electricity ; and this is made manifest by what are called 

 its polarities, i. e. by the opposite powers of like kind found .at 

 and towards its extremities. These powers are found to be 

 absolutely equal to each other ; one cannot be changed in any 

 degi-ee as to amount without an equal change of the other ; and this 

 is tnie wlien the opposite polarities of a magnet are not related to 

 each other, but to the polarities of other magnets. The polarities, 

 or the northness and soii/hness of a magnet, arc not only related 

 to each other, through or within the magnet itself, but "they are 

 also related externally to opposite polarities, (in the manner of 

 static electric induction) or they cannot exist; and this external 

 relation involves and necessitates an exactly cquaJ amount of the 

 new opjiosito polarities to wliicli those of the magnet are related. So 

 that if tl le force of a magnet a is rel.ated to that of another magnet b, 

 it cannot act on a third magnet c without being taken off from l>, 

 to an amount proportional to its action on c. The lines of mag- 

 netic force are .shown by the moving wire to exist both within 

 and outside of the magnet ; also they are shown to be closed 

 curves passing in one part of their coui-sc through the magnet ; 

 and the amount of those within the magnet at its equator, is 

 exactly equal in force to the amount in any .section including the 

 •whole of tliose on the outside. The lines of force outside a 

 magnet can be affected in their direction by the use of various 



media placed in their course. A magnet can in no way be pro- 

 cured having only one magnetism, or even the smallest excess of 

 northness or southness one over the other. When the polarities 

 of a magnet are not related externally to the forces of other 

 magnets, then they are related to each other : i. e. the northness 

 and southness of an isolated magnet are externally dependent on 

 and sustained by each other. Now, all these tiicts, and many 

 more, point to tlie existence of physical Hues of force external to 

 the magnets as well as within. They exist in curved as well as 

 in straight lines ; for if we conceive of an isolated straight bai- 

 magnet, or more especially of a round disc of steel magnetized 

 regularl}', so that its magnetic axis shall be in one diametei', it is 

 evident that the polarities must be related to each other exter- 

 nally by curved lines of force ; for no straight line can at the same 

 time touch two points having northness and southness. Curved 

 lines of force can, as I think, only consist of physical lines of force. 

 The phenomena exhibited by the moving wire confirm the same 

 conclusion. As the wire moves across the lines of force, a current 

 of electricity passes or tends to pass through it, tliere being no 

 such cuiTent before the wiie is moved. The wire when quiescent 

 has no such eun-ent, and when it moves it need not pass into 

 places where the magnetic force is greater or less. It may travel 

 in such a com'se that if a magnetic needle were carried through 

 the samo course, it would be entirel}' unaffected magnetically, i. e., 

 it would be a matter of absolute indifference to the needle 

 whether it were moving or still. Matters may be so arranged 

 that the wire when still shaU ha\e the same diaraagnetic force as 

 the medium surrounding the magnet, and so in no way cause 

 disturbance of the lines of force passing through both ; and yet 

 when the wire moves, a cuiTcnt of electricity shall be generated in 

 it. The mere fact of motion cannot have produced this current : 

 there must have been a state or condition around the magnet and 

 sustained by it, within the range of which the wire was placed ; 

 and this state shows the physical constitution of the lines of 

 magnetic force. WHiat tliis state is, or upon what it depends, 

 cannot as yet be declared. It may depend upon the ether, as ;t 

 ray of light does, and an association has already been shown 

 between hght and magnetism. It may depend upon a state of 

 tension, or a state of vibration, or perhaps some other state 

 analogous to the electric current, to which the magnetic forces 

 are so intimately related. Whether it of necessity requires matter 

 for its sustentation will depend upon what is underetood by the 

 term matter. If that is to be confined to ponderable or gravitating 

 substances, then matter is not essential to the physical hues of 

 magnetic force any more than to a ray of light or heat ; but if 

 in the assumption of an ether we admit it to be a species of 

 matter, then the hnes of force may depend upon some function 

 of it Experimentally, mere space is magnetic ; but then the 

 idea of such mere space must include that of the ether, when one 

 is talking on that belief; or if hereafter anj' other conception of 

 the state or condition of space rise up, it must be admitted into 

 the view of that which, just now, in relation to experiment, is 

 called mere space. On the other hand, it is, 1 think, an 

 ascertained fact that ponderable matter is not essential to the 

 existence of physical lines of magnetic force. — Athenceum. 



Canada in 1852: Extract from Notes on Public Snbjects, by 

 Hugh ft'eymonr Tremenheere. 



Let any one who has considered these Provinces thus far now 

 glance for a moment at their great and flouiishing towns; Ham- 

 ilton, beneath a bold escarpnu'ut and enfolding hills richly covei'ed 

 with the primeval forest; the undrdating plain on which it stands 

 divei'sified with foliage, cultivation and villas; the inlet from the 

 Lake, which forms its harbor, presenting an agreeably vai-ied 

 outline; the \illas generally in a thoroughly con-ect style of 

 architectmc, and Buri'ounde<.l by gi'ounds as well kept and as neat 



