February yth, iSgg.l PROCEEDINGS. xvii 



'Atom.' This word has a quotation dated 1477, but up to the 

 sixteenth century it was chiefly used in the Latin and Greek 

 forms, atomus or atomos. These gradually gave way to the 

 French form atome, and finally the terminal e was elided 

 according to the ordinary English usage. Dalton's work in con- 

 nection with this idea was, of course, in no sense etymological, 

 hence one is not surprised to find that his name is only intro- 

 duced incidentally under the heading ' Atomic' The most 

 curious meaning of the word ' atom ' is undoubtedly that of a 

 small interval of time, which appears to have been current in the 

 dark ages. 



From Van Helmont one very important item is gleaned, viz. 

 that the word ' gas ' is derived, not from the Dutch ' geest ' as 

 was previously thought, but from the Greek ' Xooc.' His own 

 words are as follows : " Halitum ilium ' gas ' vocavi, non longe a 

 Chao veterum secretum." The Dutch pronunciation of ' g ' as a 

 spirant accounts for its replacing the Greek x- The principle 

 meanings of chaos are void or empty space, and confusion, but 

 Van Helmont does not enlighten us as to whether he saw in 

 spirit the particles of a gas jostling one another and hurrying to 

 and fro in hopeless disorder, or whether the apparent emptiness 

 of the space occupied by gas led him to invent the word. This 

 derivation appears to be a discovery of recent date, for even 

 the Century Dictionary is not correct upon the point, although it 

 quotes from the same source, "Ortus Medicinae," " tlunc spiritum, 

 incognitum nactenus, novo nomine 'gas' voco." It therefore 

 deserves to be more widely known, and this mention before our 

 Society should assist in no small degree towards that end. 



