6C8 Mr. Ludivig 3Tond [June 3, 



WEEKLY EVENING MEETING, 



Friday, June 3, 1892. 



Sir Frederick Abel, K.C.B. D.C.L. F.R.S. Vice-President, 



in the Chair. 



LuDWiG MoND, Esq. F.K.S. M.B.I. 



Metallic Carhomjls. 



Justus Liebig, perhaps the most prophetic mind among modern men 

 of science, wrote in the year 1834, in the ' Annalen der Pharmacie,' 

 " I have previously announced that carbonic oxide may be considered 

 as a radical, of which carbonic acid and oxalic acid are the oxides, 

 and phosgene gas is the chloride. The fui'ther pursuit of this idea 

 has led me to the most singular and the most remarkable results." 



Liebio" has not told us what these results were, and it has taken 

 many years before the progress of chemical research has revealed to us 

 what may at that early date have been before Liebig's vision. I will to- 

 night bring before you some important discoveries made only within 

 the last few years by following up Liebig's idea. 



Carbonic oxide, composed of one atom of carbon and one atom of 

 oxygen, is a colourless gas, without taste or smell, which I have here 

 in this jar. It burns in air with a blue flame. When it acts as a 

 radical, combining with other bodies, we term it carbonyl, and its 

 compounds with other elements or radicals are termed carbonyls. 

 Liebif^ defined a radical as a compound having the characteristics of 

 a simple body, which would combine with, replace, and be replaced 

 by simple bodies. In more modern times a radical has been defined 

 as an unsatiated body. I am of course speaking of chemical radicals. 

 If we look at it from the modern point of view, carbonyl should be 

 the very model of a radical, because only half of the four valencies of 

 carbon are satiated, the other two remaining free. Carbonic oxide 

 should even be a most violent radical because amongst all organic 

 radicals it is the only one we know to exist in the atomic or free 

 state. All the other organic radicals, even such tyj)ical ones as 

 cyanogen and acetylene, are known to us as molecules composed of 

 two atoms of the radical, so that the cyanogen gas and acetylene gas 

 we know should more properly be called di-cyanogen and di-acety- 

 lene ; they consist of two atoms of the radical cyanogen or of the 

 radical acetylene, the free valencies or combining powers of which 

 satiate or neutralise each other. On the other hand, carbonic oxide 

 gas, as I stated before, makes the sole exception. Its molecule con- 

 tains only one atom of carbonyl moving about with its free valencies 

 unfettered by a second atom. For all that, carbonic oxide is by no 

 means a violent body, but the yery reverse, and instead of being 



