42 Mr. W. Sutherland on the Fundamental 



gramme-molecule (60 grammes) of acetic acid from its state 

 at the ordinary boiling-point into the monomolecular state is 

 4* 8 kcal., so that from the heats of formation of the acids, as 

 given by Thomsen, we must subtract about 5 kcal. to get 

 the heats of formation of the monomolecular acids and thus 

 his value for t, namely 120, must be reduced to 115. In our 

 notation we have the following relations : — 



In the aldehydes, 



/(O : 0)+/(CH) =65-4, .-. /(C : 0) =50-4 ; . (34) 



in the ketones, 



/(C:0) = 54*2; (35) 



in the acids, 



/(C:0)+/(O0)+/(0H) = 115; (g6) 



in the esters, 



/(C:0)+/(C-OC) = 105; (37) 



in the anhydrides, 



2/(C:0)+/(C'0-C) = 165-9;. ...... (38) 



in the carbonates, 



/(C:0)+2/(O0'C) = 162-1 (39) 



From the last two equations it would appear that/(C : 0) 

 and/(C'0-C) must be nearly equal and have each a value 

 about 54, but in (33) with the ethers we found for /(C'O'C) 

 the value 37, which is in conflict with that just found. This 

 conflict is due to (39), which for the present we will exclude 

 from consideration. 



Using in (36) the value for/(00) +/(OH) given by (27) 

 in the alcohols, namely 44*5, and using in (37) and (38) the 

 value 37 for /(C'O'O) given by (33) for the ethers, we get 

 the following list of values for /(C:0), namely 50*4 in the 

 aldehydes, 54*2 in the ketones, 70*5 in the acids, 68 in the 

 esters, 64*4 in the anhydrides, and if we now take account of 

 (39.) it is 88*1 in the carbonates ; these cluster about the 

 following three mean values, namely, 52 in the aldehydes and 

 ketones, 68 in the acids, esters, and anhydrides, and 88 in 

 the carbonates. Now if we denote the junction of the of 

 OH to in the characteristic acid group CO OH by the 

 symbol (C'O acid) then the equations (34) to (39) become: — 

 in the aldehydes, 



/(C:O)=50-4; 



in the ketones, 



/(C:0) = 54-2; 



