Mr. A. S. Couper on a Neiv Chemical Theory. 113 



S ...„2 entering into communication with ^4- "O-O ••■^4 



tl^Tf^r^ ""^ *^' ^^-T-"" ^^ ^^^ sulphuric acid and the two 



h.?r vS """^.^f "" ""l *^^ f ^^"' ("^^ ^° P^-e«^"^e «f each other) 

 being m different (perhaps different electric) conditions, mutually 

 Joo.en then-former affinities and reunite themselves to the (elec- 

 trically ?) difterentatoms of oxygen of these respective combinates. 

 wifl '^'"f P^^'Ple may naturally be expected to display itself 

 with regard to acids and bases. The oxygen of an acid unites 

 Itself to the (electrically ?) different oxygen of watei The oxy^^^^^^ 

 ot a base on the same principle has an affinity for the electrically 

 aitterent oxygen of water. -' 



It will be observed — 



1. That the oxygen of the water of an acid can only be expeUed 

 by that of a base, and vice versa. 



2. It is to be remarked that it is not the metal of a base which 

 exchanges places with the hydrogen of the hydrate of an acid: 



InV!kn r.f ' '^'1 '"''^ }}t ^^''''^ "^ ^^'^ «^yS^" °f the metal 

 and a of the acid, would be greater for the oxygen of the water 

 han the affinity of the hydrogen foi- that sanfe ox/gen But 

 this IS not so. The very opposite is the truth. If one atom of 

 hydrogen be withdrawn from the hydrate of an acid or from the 

 hydrate of an oxide, it is universally accompanied by an atom of 

 oxygen It is evident, then, that the affinity between the posl 

 live and negative atoms of oxygen is less than that which attaches 

 Unite /o the demerit with which they form a primary com- 



A consequence of this truth is, that it is impossible to double 

 the equivalent of oxygen, if the chemical equivalents are to be 

 understood as not being in direct contradiction to any chemical 

 truth or essential feature in the properties of an element. Car- 

 bon diflers entirely in this respect from oxygen. 



There is no reaction found where it is known that C^ is divided 

 into two parts. It is only consequent therefore to write, with 

 berhardt, C^ simply as C, it being then understood that the 

 equivalent of carbon is (12) twelve. 



This value of the atom will be adopted in the following part 

 01 this paper. ' 



Sulphur, selenium, &c. being bodies displaying properties 

 similar, not to carbon, but to oxygen, it will be necessary to 

 retain the equivalent value that has generally been assigned to 



I have now shown how ordinary alcohol, CMI^O^ common 



sether, and the hydrocarbide, C^ H«, belong to the type nCM" 



Phil. Mag. S. 4. Vol. 16. No. 105. Aug. 1858. I ' 



