The subject of this paper, is of a nature to find favour with all those chemists who are disposed to recognise in the fast accumulating evidence of a new and remarkable order of chemical phenomena rich and valuable materials for the construction of a sounder and more comprehensive chemical theory. This new order of phenomena appears to me, nevertheless, but imperfectly appreciated and understood, even on the part of our most distinguished experimentalists. Thus, for instance, Monsieur Pasteur, the illustrious French philosopher, and with him a host of other eminent thinkers, is of opinion, that matter is indebted for its chemical and physical properties mainly and exclusively to the peculiar manner in which the atoms are grouped together. In alluding to the probable cause of circular polarisation, Monsieur Pasteur considers, that this singular property ought to be referred to the unsymmetrical disposition of the constituents, and that the restoration of the chemical symmetry must at the same time obliterate every trace of circularly polarising power.