ELISHA MITCHELL SCIENTIFIC S0CIE:TY. 37 



I 



to the word element down to a little more than a century ago, 

 when in Macqiier's Dictionary of Chemi.stry — English Transla- 

 tion, 1777 — we meet with the modern definition, worded as fol- 

 lows : 



"Those bodies are called elements which are so simple that 

 they cannot by any known method be decomposed or even 

 altered, and which also enter, as principal or constituent parts, 

 into the combination of other bodies, which are therefore called 

 compound bodies/' But he adds: "The bodies in which this 

 simplicity has been observed are fire, air, water and the purest 

 earths/' 



In Table I, will be found the supposed primal elements at 

 different periods, reaching as far back as history goes. It is but 

 just to state that Dr. Crookes recognizes the insufficiency of data 

 to support the theory of a primal element, and hardly does more 

 than suggest "protyle" as an interesting possibility. 



In Table II a list is given of those at present acknowledged 

 to be elements, with the date of discovery and name of discov- 

 erer. ^yith regard to the dates of discovery, it is interesting to 

 note that nine were known in the earliest historic times, four 

 more were discovered before the eighteenth century, fifteen dur- 

 ing the eighteenth century, and forty during the nineteenth cen- 

 tury. 



The last thirty years of the eighteenth century form an espe- 

 cial season of activity. Twelve out of the fifteen elements dis- 

 covered during that century were discovered in those years. 

 Taking the present century by decades we find that fourteen 

 elements were discovered in the first, four in the second, seven 

 in the third, five from fourth to sixth, inclusive, three in the 

 seventh, five in the eighth, and two in the ninth. Davy with 

 his discoveries made 1808 the most prolific year, but Wohler in 

 1828 runs him a close second. 



As to nationality, Germany can claim the first rank with 

 eiirhteen discovered elements. Euii^land comes next with seven- 

 teen, France lays claim to eleven, and the discovery of the 

 remainder is due mainlv to the labors of Scandinavians. It is 



