234 W. Odling, Esq. [March '30, 



WEEKLY EVENING MEETING, 



Friday, March 30, 1860. 



The Lord Wensleydale, Vice-President, in the Chair. 



William Obling, Esq. M.B. F.R.S. 



SECBETABY TO THE CHEMICAL SOCIETY. 



On Acids and Salts. 



It is natural to inquire whether the doctrines of series and substitu- 

 tions, which are essential for the association of organic products, may 

 not throw some additional light upon the simpler compounds of mineral 

 chemistry, when viewed as unitary molecules ; and particularly upon 

 the relations and properties of the mineral acids and their salts, which 

 have hitherto constituted the strongholds of the electro-chemical, or 

 binary, theory of combination. 



The doctrine of series affirms that chemical compounds may be 

 arranged in series, the successive members of each of which differ from 

 one another in composition by a common increment, and are associated 

 with one another by a certain relation of properties, the exact nature 

 of the relation varying with the nature of the increment. 



The doctrine of substitutions affirms that, in very many chemical 

 compounds, one or more atoms may be displaced by some other atoms or 

 groupings, and that the new bodies, resulting from this displacement, 

 correspond in constitution with the normal bodies from which they 

 were derived. The doctrine of substitutions affords great assistance to 

 the doctrine of series ; for when, as frequently happens, a gap exists in 

 any series, that gap can almost always be filled up by a substitution- 

 representative of the missing body. 



(a.) There are four acid compounds of hydrogen, two volumes of 

 each of which contain one volume of hydrogen, namely : 



HF Fluorhydric acid. 

 HCl Chlorhydric acid. 

 HBr Bromhydric acid. 

 HI lodhydric acids. 



