104 PRESCOTT — THE RoLE OF CARBON. [April 7, 



the union of each sixth of the hydrogen to the unit of oxygen is the 

 same. Were chemists to abandon structural formulae, were they to 

 go further and desert the atomic theory, all the facts heretofore 

 communicated would remain to be told if possible in other terms to 

 the eye and ear. 



There has been some reaction against the devotion paid to mole- 

 cular constitution, and there may well be a protest against certain 

 besetting tendencies in the teaching of this subject. Both teacher 

 and investigator ought to be on guard against the assertiveness of 

 the structural formula. Let us welcome as a corrective the in- 

 creasing service of empirical formulae, the appearance of the formula 

 index once a year in the journals, the constant uses of the Lexicon 

 of Carbon Compounds, and the adoption of empirical formulae 

 frequently for summation and comparison as well as for contrast. 

 Of course I refer only to these formulae when of determined mole- 

 cular weight, and we must recognize that no small share of the 

 vantage ground in organic chemistry since 1890 is indebted to the 

 new methods of molecular weight determination. 



It is the nature of the carbon atom that has made attractive to 

 chemists the work they have done upon molecular structure. It 

 was long ago established that the character of a compound depends 

 partly upon what elements unite to make it and partly upon the 

 order of their union. No atom in a molecule is wholly without 

 influence upon every other however remote. And as to the effect 

 of any element in a compound, it is a fair conclusion that the num- 

 bers of its atoms within the molecule count for something, the rela- 

 tive position of its atoms may count for more, the structural 

 concentration of its atoms will count for most. 



When the nature of the proteids and other matters manifesting 

 life shall become known we may be sure that molecular constitution 

 will be included in that knowledge. We may be sure that the 

 carbon atom, or some theoretical equivalent of what we now term 

 the atom, will be a very determinate part of the question. This is 

 not to say that chemical synthesis alone can compass vitality, but 

 rather that vitality must still depend upon the chemical constitution 

 of the vitalized material. We cannot speak lightly of the limits 

 of what may come to be defined as the molecule, or count confi- 

 dently upon future restrictions of its extent. We may well admit, 

 however, that the rim of the molecule wherever placed must 

 continue to bound the province of chemical study. 



An7t Arbor y Mich.^ March 57, 1^04. 



