CHEMISTRY. 



By H. Carrington Bolton, 



Professor of Chemistry, Trinity College, Hartford. 



GENERAL AND PHYSICAL. 



Possible Variability of the Laic of Definite Proportions. — One of the 

 most interesting subjects discussed during the year (1883) concerns the 

 fundamental conceptions of chemical philosophy. The whole super- 

 structure of modern chemistry rests upon the atomic theory and on the 

 absolute character of that function of an element which we call atomic 

 weight; hence, any proposition to throw discredit on these conceptions 

 may well be regarded as revolutionary. The discussion was introduced 

 by Prof. Adolphe Wurtz, who presented to the Society chimique de Paris 

 a summary of the views of Boutlerow; these were emphatically in- 

 dorsed by Schiitzenberger, and have since elicited a communication from 

 Prof. Josiah P. Cooke, jr., of Harvard College. 



Schiitzenberger announced in 1880 or 1881 that in analyzing some hy- 

 drocarbons the sum of the carbon and hydrogen was 101 for 100 parts 

 of material, the result under other conditions being normal. Boutlerow 

 has called attention to this anomaly as illustrating views he has held 

 for three years. He expresses the opinion that the chemical value of 

 a constant weight (or rather mass) of a substance may vary, and that 

 the so-called atomic weight of an element may be simply the carrier of 

 a certain amount of chemical energy which is variable within narrow 

 limits. He further asks the question whether Prout's hypothesis may 

 not be a true law which, like that of Mariotte, admits of a limited varia- 

 tion. Numerous facts are cited, chiefly the results of quantitative anal- 

 yses, which seem to confirm these views. If such views prevail, chemi- 

 cal combination can no longer be regarded as the juxtaposition of the 

 definite invariable masses we call atoms, but must be considered as the 

 reciprocal saturation or interpenetration of masses which may vary with 

 the relative strength of their chemical energy acting at the time. 

 Schiitzenberger, who took part in the discussion, enumerated many 

 facts which led him to the conclusion that the law of definite proportions 

 is not so absolute as generally supposed. We have space but for a 

 single example : When water is synthesized by reduction of a known 

 weight of CuO, by weighing the reduced copper and the water formed, 



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