Henry's Chemistry. 333 



The respectable author of the Elements of Experimental Che- 

 mistry had suffered himself, for the preceding two or three editions 

 of his popular work, to fall under the above description. A 

 book, however, intended especially for students, derives a great 

 part of its value from the justness and felicity of its arrangements. 

 Chemical phenomena have been, of late years, so repeatedly exhi- 

 bited to the world in so many publications, and are, generally 

 speaking, so clear and uncontroverted, that there is little merit in 

 their mere collection. It is the skilful initiation of the Tyro's inind 

 into the methods of chemical research, and the natural collocation 

 and development of details, both as to the facts themselves, and 

 the means by which they were discovered, that are required and 

 expected from the author of an elementary work. In these re- 

 spects, the model offered by Lavoisier has been too little imitated 

 by late compilers of systems. By studying the elements of that 

 philosopher, the mind not only gets stored with a series of impor- 

 tant facts, but acquiring imperceptibly logical force and precision, 

 becomes fitted for conducting independent investigations. How 

 different an impression is made on the student's mind, by some of 

 our late systematic performances. A multitude of objects is ex- 

 hibited to his view, like a phantasmagoreal dance, calculated to 

 bewilder and fatigue the most resolute ; and altogether to deter 

 the less zealous from entering this hermetic labyrinth. 



The genuine principles of chemical classification were first 

 established by Davy, in his Bakerian Lectures of 1806, 1807, 

 and 1808. Here the electrical relations of the elementary or 

 undecompounded bodies, and of many compounds were demon- 

 strated ; relations which served as the basis of his arrangement in 

 the Elements of Chemical Philosophy, which he published in 1812. 

 Berzelius indeed has long regarded the electrical relations of 

 chemical bodies, as the ground-work of their classification, but 

 his notions on electro-chemistry are not unfrequently obscure and 

 hypothetical *. 



Oxygen, chlorine, iodine, and fluorine, besides their electrical 

 properties, have other characters so prominently defined, as to 

 entitle them to a primary and peculiar place in chemical systems. 



* We are sorry to observe that our censure of some of the hypotheses of Ber- 

 zelius, and more especially of his system of symbols and formulae, (which we 

 shall, nevertheless, continue duly to administer as occasion may required lias 

 been mischievously misrepresented as a personal attack upon the Professor, 

 for whose talents, industry, and analytical skill we entertain the highest re- 

 spect, and therefore beg leave to deprecate any such interpretation of onr re- 

 marks. The mo<t useful, judicious, and skilful, are sometimes mistaken in 

 the estimate of their own powers ; *« optat Ephippia Bos piger; oplat arare 

 cal'allus." The lii.^li character of Berzelius as an acute and successful analyst, 

 and the ability with which he has handled some of the most abstruse theore- 

 tical departments of chemistry, gave a mischievous authority to his hypotheti- 

 cal speculations, and our animadversions have been, and will be, solely con- 

 fined to the latter. 



