420 



Dr. C. R. A. Wright on the Relations between 









Numher of 











hvdrocarho- 







Affinity-values. 





nous methyla- 



tions for one 



hydroxylic 



Heat- 

 disturhance. 









methylation. 





Ethvlic alcohol 



.. 637 



Ethvlic ether . 



. 330 



1 



—30-7 



Methvlic alcohol 



.. 53-4 



Ethvlic ether . 



. 33 



2 



-20-4 



Aravlic alcohol 



.. 85-2 



Amvlic ether . 



. 83-5 



4 



- 2-7 



Ethvlic alcohol 



.. 03-7 



Amvlic ether . 



. 83-5 



7 



+ 19-8 



Methylic aleohol 



.. 53-4 



Amylic ether . 



.. 83 5 



8 



+301 



These numbers seem to indicate that the heat-absorption in 

 the first hydroxylic methylation is close npon —40, whilst the 

 heat-evolution for each successive hydrocarbonous methylation 

 is close upon -f- 10, — a conclusion nearly the same as that deduced 

 from the acids and amylic ethers, viz. that 4 hydrocarbonous 

 methylations evolve jointly about as much heat as is absorbed 

 during 1 hydroxylic methylation. Manifestly, however, the 

 experimental data used in the calculation of the affinity-values 

 are not known with sufficient accuracy to warrant quantitative 

 deductions of this kind, though they suffice, due allowance being 

 made in two or three instances (e. g. ethyl butyrate) for evident 

 large errors, for the deduction of qualitative results, such as the 

 determination of the algebraic sign of the heat-disturbance du- 

 ring a given kind of operation. As above stated (§ 16), the 

 value for amylic ether (83*5) is probably a little too high; the 

 difference, however, will probably not affect the general result. 



31. D. The conversion of water into methylic alcohol is a case 

 in point. 



Affinity-value. Affinity- value. Heat-disturbance. 



Water, 579 | Methylic alcohol, 53*4. -4'5 



It is here noticeable that the heat-absorption in this hydroxylic 

 methylation is considerably less than the heat-evolution during 

 the hydrocarbonous methylation of methylic alcohol producing 

 ethylic alcohol; so that the transformation of water into ethylic 

 alcohol is attended with heat-evolution. 



Heat-disturbance. 

 Water, 57*9 | Ethylic alcohol, 637. +5-8 



This result is doubtless connected with the non-existence of 

 carbon as a constituent of water. 



32. Another general rule noticeable is, that if an operation be 

 performed symbolically denoted by the replacement of the symbol 

 H a by the symbol 0, heat is evolved during the process ; thus : — 



