NOMOS. 5 



the law of the laboratory in a region where they 

 encounter a certain amount of resistance in moving. 

 It may be shown also that these movements must 

 begin as well as continue under these circum- 

 stances. And hence it is not unreasonable to sup- 

 pose that the law of the laboratory may be the 

 law which governs the movements of the heavenly 

 bodies. 



But be this as it may, it is very certain that the 

 force of gravity is not sufficient of itself to account 

 for every phenomenon in which it is supposed to be 

 the principal or exclusive agent. It does not fully 

 account for the tides, or for the wonderful changes 

 which are exhibited in the form of comets. In order 

 to account for these phenomena, it appears to be ne- 

 cessary to have recourse to another agency an 

 agency which must operate, but whose operation has 

 never yet been properly considered. This is heat. 

 Nay more, it is also found that the same agency 

 which will account for the tides, and for the changes 

 in the forms of comets, will kindle a fire in the heart 

 of the earth, and keep the land above the waters in 

 such a way that in very truth " the bounds of the 

 sea are fixed by a perpetual decree, so that they 

 cannot be passed ; " while at the same time it will do 

 much to elucidate what is dubious in the various 

 versions of the past history of the earth. It is found, 

 indeed, that another power, and one scarcely inferior 

 to that of gravity, must be admitted into the idea of 

 cosmical law ; and as this second power enters into 

 the idea of the law of the laboratory, this very fact 



" 



