40 Mr. W. Sutherland on the Fundamental 



34*6, and in methylphenyl ether 37*7, or, on the average, about 

 37 : thus we add another to our list of functions, namely, 



/(O0*C) = 37. . ..... (33) 



But/(OOC) should equal 2/(00), and therefore in the 

 ethers /(C*0) = 18'5 in conflict with the 15 of (32) from the 

 alcohols H 2 and H 2 2 ; the difference is probably due to 

 secondary influences of unconnected atoms on one another, 

 and these are^ neglected in the present discussion. 



In the case of ethylene oxide CH 2 OCH 2 , for which p + ad is 

 94, Thomsen argues that with the value 15*76 for r and 

 2 x 15*76 for the junction of to two C atoms, the Ar and 

 this 2 x 15*76 or 94*54 account for the whole of p + ad, namely 

 94, and urges therefore that the two GH 2 groups cannot be 

 united by a single binding according to the accepted structure 

 of CH 2 OCH 2 , for that would introduce an additional 13*9 for 

 the thermal value of this binding and would give a result dis- 

 cordant with experiment. According to Thomsen, then, 

 CH 2 OCH 2 must be supposed to involve in its structure no 

 direct connexion of the one CH 2 with the other, and it must 

 therefore be a genuinely unsaturated compound. But in 

 connexion with the general chemistry of CH 2 OCH 2 it seems 



better to take 94 — 60 or 34 as the value of/ ( q ) , the arrange- 



cc 



ment n denoting the ring (or triangular) connexion of the 



atoms, and to wait for more knowledge of the thermochemistry 

 of ring nuclei before attempting to interpret the fact that 



/( q J is actually less than/(C*0*C). 



5. Aldehydes, Ketones, Acids, and Anhydrides. — When the 

 formula for an aldehyde C a H 2a O is written in the form 

 Ca-iH 2a -iCOH we can write for p + ad the equation 



p + ad = (a — l)v l + (2a — \)r + q, 



where q is the heat developed in the attaching of H and to 

 C in the aldehyde group COH ; from the heats of formation of 

 acetic, propionic, and butyric aldehydes Thomsen gets for g 

 the mean value 65*4. In a ketone C a H 2a+1 COO/3H 2j3+ i 

 or C a H 2rt O we have p + ad— (a — \)v 1 + 2ar + s, where s is the 

 heat of junction of to to produce the CO characteristic 

 of the ketones ; from dimethyl and methylpropyl ketones the 

 mean value found for s is 54*2. 



Again, in the acids C a _ 1 H 2a _i COOH we have the equation 

 p + ad= (a — l)vi + (2a— 1) r + 1, where t is the heat of attach- 



