TO THE FARMER. V 



sible to the sailor, until the magnetic needle was put 

 into his hand. And so, in chemistry, no predeter- 

 mined plan or systematic course of investigation 

 could be confidently pursued, until the introduction 

 and employment of the balance. By means of the 

 balance, which furnishes a trustworthy guide, and in 

 no less degree a certain test for chemical experi- 

 ments, the confident assurance, forming the founda- 

 tion of scientific chemistry, that all chemical combi- 

 nations and decompositions take place only in ac- 

 cordance with the fixed and unalterable measure and 

 weight of the ultimate elements of bodies, was, 

 amongst other discoveries, first arrived at. This cer- 

 tainty may now be regarded as a natural law. 



Many such laws of nature have been already as- 

 certained in the continued prosecution of chemical 

 discovery ; they enable us to reply with entire confi- 

 dence to those questions which have been proposed 

 respecting the mode and the cause of chemical ac- 

 tion. Unlike human laws, they cannot be arbitra- 

 rily evaded or changed. Their discovery has placed 

 us in a condition to propound, rationally to discuss, 

 and to estimate beforehand scientific chemical gen- 

 eralizations, by which alone we can attain to a clear 

 and luminous apprehension of those chemical pro- 

 cesses that happen in conformity therewith. It may 

 be objected, that all our knowledge is fragmentary. 

 This, indeed, no chemist will refuse to acknowledge ; 

 but notwithstanding such a confession, no undue 

 presumption can be imputed to him for cherishing 



