PROCEKDINGS OF PROVINCIAL SOCIETIES. 139 



air, pass away with the phenomena of heat and flame ; the power 

 of cohesion is overcome, and the visible remains now subject to the 

 power of gravitation, are only a few white ashes, which a breath of 

 wind will scatter away. 



The slow and silent operations of this agent are, perhaps, less 

 striking, but equally effective. Thus, no sooner does the sun dart 

 his ray upon the earth in the morning, than the repose which all 

 substances might seem to be enjoying is directly, though, perhaps, 

 unobservedly, terminated. Particles of water, whether in form of 

 dew, or spreading upi)n the surface of the ocean, a river, or a lake, 

 expand, and, no longer subject to the earth's attraction, spring off 

 into the higher regions of the atmosphere. The air upon which 

 the sun's heat is acting also expands, ascends, and gives rise to cur- 

 rents of wind. The different tribes of living beings are variously 

 stimulated to activity ; feeble currents of electricity are, at the same 

 time, excited, and all nature put in motion. As the sun reaches its 

 zenith, larger or more considerable floods of caloric are poured upon 

 the earth, evaporation goes on with the utmost rapidity, the winds 

 blow stronger, and the functions of life are more vigorously per- 

 formed. The vast streams of vapour reaching, the higher regions, 

 are there robbed of the caloric which carried them upward, and are 

 condensed into an arched and snowy mass of cloud. The electricity 

 caused by evaporation accumulates ; and, at length, the vivid flash, 

 the succeeding thunder, and torrents of rain, restore again the 

 aqueous atoms to their source. This is only a very imperfect ac- 

 count of the disturbances and consequent phenomena produced by 

 the agency of light and heat, flowing in upon the earth from the 

 sun, but it is sufficient to assure us that every particle of matter is 

 obedient to peculiar physical powers. If further testimony is needed 

 to convince any one of this fact, it is afforded by circumstances of a 

 still more striking character, daily falling under our observation. 

 The explosion of gunpowder — the bursting of strong leaden pipes 

 by the freezing of water — the extraordinary power of steam— elec- 

 tricity and magnetism — the curious effects of chemical affinity — the 

 symmetrical forms of crystals — and, lastly, the increasing revolu- 

 tions of the earth itself — are all so many proofs of the existence and 

 activity of physical power, and afford to the contemplative mind a 

 very exalted idea of the omnipotence of that Supreme Intelligence 

 which governs and directs the whole. 



The lecturer then entered upon the consideration of the laws by 

 which the phenomena of physical power are regulated, and pointed 

 out the importance of a knowledge of the laws of nature — " so that 

 in all we attempt we may not vainly struggle against some insupe- 

 rable difficulty opposed to us by natural causes, and on the other 

 hand that we may be enabled to avail ourselves of those important 

 auxiliaries which a knowledge of them does not fail to bestow 

 upon mankind." 



This interesting lecture was illustrated by various experiments in 

 chemistry, electricity, and electro-magnetism, calculated to develope 

 and enforce the lecturer's views of physical power. 



