80 THE YEAR. 



terrestrial action, might probably, ere now, have been 

 as well understood as those by which the lengths of 

 the days are regulated. At present, however, this is 

 the untrodden field of natural history, and, unfortu- 

 nately, it seems to be one which there is a reluctance 

 to explore, though why there should be (other than its 

 difficulty, and where the true spirit of inquiry is, that 

 should be a stimulus) it is not easy to discover. No- 

 thing comes without a cause ; and the cause of every 

 phenomenon in nature is nothing but the phenomenon 

 immediately antecedent. We find that certain cir- 

 cumstances in the soil and the weather as uniformly 

 produce, or, if the expression is liked better, foster 

 certain organized beings, as that certain positions of 

 the earth, with regard to the sun, produce a certain 

 length or time of the day ; and if we could get hold 

 of all the elements, and study their modes of working, 

 there would really be nothing more miraculous in pre- 

 dicting a good or a bad season, than there is in pre- 

 dicting a long or a short day ; or in calculating a 

 thunder-storm, than there is in calculating an eclipse. 

 Mere expansion by heat, and condensation by cold, 

 and mere oxygenation and deoxygenation of plants 

 and animals, have been too much regarded as the sole 

 functions of the atmosphere, and that is one of the 

 chief reasons why so little progress has been made in 

 the natural history of that wonderful and all pervading 

 fluid. Our own senses tell us that it is the vehicle of 

 far more subtile energies than these. A single grain 

 of assafoedita or of musk, will give out its scent to the 

 changing air of a room for a dozen of years, without 

 one being able, by the nicest balance, to detect the 



