THE SALTS OF THE SEA. I59 



the tendency of the mstrument to change its performance with the 

 changing influences of temperature. 



This contriv^ance is called a compensation ; and a chronometer 

 that is well regulated and properly compensated will perform its 

 office with certainty, and preserve its rate under all the vicissi- 

 tudes of heat and cold to which it may be exposed. 



340. In the clock-work of the ocean and the machinery of the 

 universe, order and regularity are maintained by a system of com- 

 pensations. A celestial body, as it revolves around its sun, flies 

 oflf under the influence of centrifugal force ; but immediately the 

 forces of compensation begin to act ; the planet is brought back 

 to its elliptical path, and held in the orbit for which its mass, 

 its motions, and its distance were adjusted. Its compensa.tion is 

 perfect. 



341. So, too, with the salts and the shells of the sea in the ma- 

 chinery of the ocean ; from them are derived principles of com- 

 pensation the most perfect ; through their agency the undue ef- 

 fects of heat and cold, of storm and rain, in disturbing the equi- 

 librium, and producing thereby currents in the sea, are compen- 

 sated, regulated, and controlled. 



342. The dews, the rains, and the rivers are continually dis- 

 solving certain minerals of the earth, and carrying them off' to the 

 sea. This is an accumulating process ; and if it were not com- 

 pensated, the sea would finally become as the Dead Sea is, sat- 

 urated with salt, and therefore unsuitable for the habitation of 

 many fish of the sea. 



The sea-shells and marine insects aflford the required compensa- 

 tion. They are the conservators of the ocean. As the salts are 

 emptied into the sea, these creatures secrete them again and pile 

 them up in solid masses, to serve as the bases of islands and con- 

 tinents, to be in the process of ages upheaved into dry land, and 

 then again dissolved by the dews and rains, and washed by the 

 rivers away into the sea. 



343. The question as to whence the salts of the sea wxre orig- 

 inally derived, of course has not escaped the attention of philoso- 

 phers. Some have advanced the idea — Darwin, the poet, among 

 others — that they came originally from the land, and were washed 

 into the sea by the rivers and the rains. There seems to be plaus- 

 ibility in this idea ; but there is reason for questioning it, as will 



