ARE THE ELEMENTS ELEMENTARY ? 463 



making his establishment a medium of exchange between parties in 

 diiferent localities. For instance, A lives in Central New York ; he 

 has plenty of Menobranchus, and would exchange them for Mtnopoma 

 from the Ohio River, or the gars and spoonbills of the Mississippi, of 

 which B has more than he wants ; while both these parties desire 

 sharks, and skates, and pipe-tishes, and the large lamprey from the 

 seacoast where C lives. To purchase and keep all tliese and many 

 more such on hand involves an enormous expense and risk to a single 

 individual ; whereas, if, under certain conditions, Prof. Ward re- 

 ceived good specimens of these forms, and stored them at the owner's 

 risk as to fire, and expense as to alcohol, etc., then he could, at a fair 

 commission, transfer them to those who desired them without the 

 expenditure now incurred. 



The arrangement could be made like that of the naturalists* 

 agency for books in Salem, Massachusetts, and a periodical list of 

 specimens and prices could be issued. The prices would serve as 

 guides for either exchange or direct purchase. 



Such a system of transfer would, it seems to us, not only enable 

 new institutions to rapidly form type collections for class-room instruc- 

 tion, but also encourage them to collect large numbers of duplicates 

 of the forms peculiar to their localities. In this way we should ascer- 

 tain the extent of individual variation, the manner and rate of devel- 

 opment and growth, and, by preparations made on the spot, the struct- 

 m-e of the brains and other soft parts, which are seldom perfectly 

 preserved in specimens sent in alcohol from a distance. 



-*- 



ARE THE ELEMENTS ELEMENTARY? 



By F. W. CLAEKE, 

 peofessoe of chemistey and physics in the university of oinoinnati. 



WHAT are the so-called chemical elements ? Are they really ele- 

 ments, or only compounds of remarkable stability ? It would 

 be hard to find in physical science a question which has been oftener 

 asked than this. It has furnished all sorts of investigators Avith 

 abundant food for speculation. Men of the highest scientific ability 

 have grappled with the problem, and left it still unsolved ; others 

 have constructed elaborate theories, which claimed to settle every- 

 thing. Still the debate goes on. We cannot prove that the elements 

 are truly what we call them, nor can we show beyond all doubt that 

 they are compound in their nature. We may, however, weigh the 

 opposing probabilities, and see which side of the question is the 

 stronger. Whichever way the balance turns, the superstructure of 

 chemistry will be but little affected. We know that all our recog- 



