Knowing how contented, free, and joyful is life 

 in realms of science, one fervently wishes that 

 many would enter its portals. On this account 

 many pages of this treatise are unwittingly 

 stamped with the earnest desire that the habits 

 of chemical contemplation which I have en- 

 deavored to instil into the minds of my readers 

 will incite them to its further study. 



MENDELE F, Principles of Chemistry. 



