66 Rev, J. E. Ashhy [March 23, 



Lastly, Willianison's othyl theory, although it possesses a great 

 degree of generality, and is supported by most complete analogies 

 both in mineral and in organic chemistry, is only one of many ways 

 of indicating the mutual relations of bodies. It must not be taken 

 as the sole veritable representation of the constitution of the com- 

 pounds to which it applies. There are no greater proofs of the 

 pre-existence of othyl in acetic acid, than there are of the pre- 

 existence of peroxide of hydrogen in water. 



For example, the correlations of benzamide, benzonitryl, hydro- 

 benzamide, and dibenzoylimide, are entirely neglected in the othyl 

 theory. These bodies belong to one single class ; they all contain 

 certain benzoic elements, and certain ammoniacal elements ; by the 

 absorption of water they yield ammonia, and benzoic acid or alde- 

 -hyd. But the othyl theory bears no reference to this point of view ; 

 it separates benzamide widely from its congeners. Thus we are 

 told that the first body contains the compound radicals benzoyl 

 (analogous to othyl) and amidogen ; the second, the compound 

 radicals phenyl and cyanogen ; the third, nitrogen and the com- 

 pound radical benzyl (analogous to acetyl), whilst, with regard to 

 the fourth, as to many other bodies, the compound radical theory 

 fails altogether. 



In the three best known hydro-carbons, coal-gas, olefiant-gas, and 

 benzine, as in many other bodies ordinarily represented as contain- 

 ing compound radicals, the conception of self-existent constituent 

 compound radicals, is not only unnecessary but irrational. The 

 particular groupings of atoms, which we denominate compound 

 radicals, do not have an existence apart from the other constituents 

 of the bodies, into which they are said to enter. 



[W. 0.] 



WEEKLY EVENING MEETING, 



Friday, March 23. 



Henry Bence Jones, M.D. F.R.S. 

 in the Chair. 



Rev. John Eyre Ashby, 



On {so-called) Catalytic action and Combustion; and 

 theories of Catalysis. 



The study of Catalysis is a study of forces. It comprehends the 

 conditions under which force is exerted in a peculiar manner in 

 chemical decompositions and combinations, and of the nature of the 

 force only as compared with forces at work in chemical changes, 



