18-4 TRAXSACTIONS OF THE [MARCH 15, 



The correlation between atomic weights and physical proper- 

 ties is being extended, and now embraces the fusibility, boiling- 

 points, general afEnities, color, occurrence in nature, physiolo- 

 gical functions, and many other factors." Dr. Carnelley," who 

 has been active in developing this subject, at the Aberdeen meet- 

 ting of the British Association, proposed a " reasonable explana- 

 tion" of the periodic law;'" he regards the elements as com- 

 pounds of carbon and jether, analogous to the hydrocarbon 

 radicals, and suggests that all known bodies are made up of tliree 

 primary elements, carbon, hydrogen, and aether — an assumption 

 which cannot be disproved. 



In recent years the periodic system has exerted noteworthy in- 

 fluence on the classitication of the elements and their com- 

 pounds. It is of positive utility in determining unsettled ques- 

 tions concerning new and rare elements, and is destined to 

 maintain a lasting hold on chemical philosophy. 



(7.) The question whether the known elements are truly pri- 

 mary forms of matter has long occupied the thoughts of chemists," 

 and the problem constantly acquires new features. The influ- 

 ence of high temperatures on the spectra of the metals has been a 

 fruitful source of speculations. In 1ST8, the English astronomer 

 and physicist Lockyer" announced the discovery of the resolu- 

 tion of the elements into one primary matter; but when Lock- 

 yer's paper was read before the Eoyal Society his discovery proved 

 to be little more than a hyj)othesis, and that not a new one, ho 

 having been virtually anticipated by Professor F. W. Clarke, of 

 Washington.'" However, Lockyer's hypothesis was based in i)art 

 upon experimental evidence. After eliminating coincidences in 

 the lines of the spectra of various metals, due to )mi)urities, so 

 large a number of identical lines remained that he advocated the 

 assumption that these are ])roduced by a primary matter com- 

 mon to the so-called elements. He pointed out that in the hot- 

 test stars, Sirius for example, hydrogen only is present, and 

 argued that at extremely high temperatures the so-called ele- 

 ments are broken up into hydrogen, the ultimate matter of the 

 universe. Lockyer's announcement excited, temporarily, a lively 

 interest, but his views are not regarded as supported by suflBcient 

 evidence. 



More recently, the doctrine of ''structure" has been bor- 

 rowed from organic chemistry, and ai)plied to the elementary 

 bodies; the relations existing between the elements is so similar 

 in many respects to the relations between the hydrocarbons in a 

 homologous series, that the elements have been regarded as com- 

 pounds of carbon with an unknown primary form of matter. 

 Experimental evidence is lacking, but the hypothesis takes a. 

 plausible form. 



