3 IS On Chemical Philosophij. 



wRtex is separated from it, the moment this power is HherKted it 

 instantly passes with all its energies and force into some other 

 substances :^-these actions on ourselves we call scalding, buru- 

 jng-, iieating, &:c. So in making coal-gas, or any of the gase>j 

 by heat, the pipes are hot only so long as vapour comes over, &c. 

 The atmosphere and all the permanent gases, 1 consider (and 

 I trust in the subsequent Essays will prove satisfactorily) to be 

 ihc same grand power holding substances in solution, by which 

 its density is increased, its active properties and energies sus- 

 pended or occupied in the exact proportion to its degree of 

 saturation, or of their qiianiity in any given volume. Hence in 

 elevated regions, witii less oxygen and nitrogen and no moisture 

 to act upon, its energies are not suspended; and thus its greedi- 

 ness for moisture occasions intense thirst, and evaporation un- 

 impeded by pressure goes on with intense rapidity. I consider 

 also that this atmosphere or the permanent gases are solutions 

 of substances in this grand and universal solvent, and differ froni 

 the solution of water merely in tliis; that they are not separable 

 from it at any known temperature ; and that thus all above this 

 point acts upon aiiv other soluble substance, dissolves it,and mixes 

 it with the atmosphere or any of these gases. Moisture in this 

 way is dissolved in this power, and that in quantities in propor- 

 tion to its excess ; and consequently the quantity of moisture 

 held in solution in our atmosphere varies with the temperature 

 or uncombined state of this power, with season and with cli- 

 mate. HencC; when this excess or the temperature is increasing, 

 and of course going before the saturated point, as in spring, we 

 perceive the greatest difference between the spring and autumnal 

 shower, — that vegetation goes on at a temperature in spring, at 

 \vhich it decays in autumn : and hence the difference of our fecl- 

 ii'.gs in one season and the other, and of our diseases ; that at 

 one season we have inflammatory and at the other putrid dis- 

 eases; that a thorougli knowledge of this principle, and of its in- 

 fluence, explains the diseases of climate and of situation. Hence 

 also the explanation of many singular facts connected with mag- 

 netism and the polar regions (of which afterwards): that this 

 power, not being separable from these permanent gases at anr 

 known temperature; tliat all above this unknown temperature, 

 and under it, necessary to raise and suspend water, as at the 

 polar regions, appears in this form of electricity, or in its most 

 separate and pure state, (we can perceive it by the sense of seeing) 

 as I consider its state in the form of electricity to be ; and thus 

 the northern lights change with the changes in tcniperatvnc, 

 and follow the parts where the largest collections of ice are 

 formed, &c. All these and several other facts appear to me ex- 

 plained on the.e views. The power of the steam-engine de- 

 pends 



