Gorhani's Elements of Chemistry* 33'<' 



ail those precursors which are necessary to announce so im- 

 portant a body, and then we may begin upon its history 

 with the commanding advantage, of being freed from the ne- 

 cessity of anticipating, and of being always perfectly intel- 

 ligible. 



It was one of the great charms of Dr. Black's mode of 

 instruction, that he carried his pupils forward in their course, 

 with an ascent so gentle, that they scarcely perceived that 

 they were mounting, till they learned it from the constantly 

 increasing extent of the horizon. 



We are aware that it is not the supposed analogy with 

 oxigen alone, which induces the early mention of chlorine ; 

 writers and teachers are allured, by the imposing extension 

 of the analogy so as to include four principles of combustion, 

 namely, oxigen, chlorine, iodine, and fluorine. Of the last 

 we have already remarked that its very existence is ex- 

 tremely hypothetical, and its nature is if possible still more 

 so. The fact is otherwise with iodine ; this is a well es- 

 tablished and well characterized body — but except the at- 

 traction to the positive pole in the voltaic arrangements, 

 which property it enjoys in common with oxigen and chlo- 

 rine, what peculiar claim has it to be ranked as a supporter 

 of combustion. Certainly it is in no common sense a sup- 

 porter of combustion, and the solitary fact that its vapour 

 supports combustion, or something that appears like it, in 

 the case of potassium, can scarcely be considered as giving 

 it a title to rank along with oxigen and chlorine to the for- 

 mer of which, it is in all other respects, and to the latter in 

 most respects, so unlike. Indeed this very remarkable 

 body is so peculiar in the tout ensemble of its properties, 

 that it appears at present better to give it a niche by itself 

 whenever it may appear most convenient ; but we are dis- 

 posed to think that it ought not to be introduced very early, 

 and that wherever it may be placed it should be postponed 

 to chlorine. 



As to the new theory of chlorine itself this is not the 

 place to discuss a subject, which, traced into all its ramifica- 

 tions, and discussed in all its important bearings, would alone 

 occupy a volume. We are aware that most chemists have 

 adopted the new views, and that in the most recent system? 



* Excepting its electrical relations, 



Vol. m.....No, 2/ 43 



