226 
Proceedings of the Boyal Society 
5. On the Chemical and Physical Principles in Connection 
with the Specific Gravity of Liquid and Solid Substances. 
By Otto Eichter, Ph. D. Communicated by Professor 
Maclagan. 
The subject of this paper, is of a nature to find favour with all 
those chemists who are disposed to recognise in the fast accumulat- 
ing 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 pheno- 
mena appears to me, nevertheless, but imperfectly appreciated 
and understood, even on the part of our most distinguished experi- 
mentalists. 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. Again, in order to account for the 
fact, that certain salts, for instance the chlorate of soda, cease to 
exhibit circular polarisation so soon as they are made to pass from 
the solid into the liquid state, he ventures even a step farther. 
According to him these optical phenomena are really due to two 
distinct causes, either to the dissymmetrical distribution of the 
atoms within the limits of each individual molecule, or to the 
spiral form of aggregation impressed upon entire masses of mole- 
cules, although these latter may, as individuals, exist in a state 
of chemical symmetry and optical neutrality. Monsieur Pasteur 
adopts the following mode of reasoning ; — The chlorate of soda 
owes its optical activity mainly and exclusively to the spiral form 
of aggregation ; and being destitute of that property, so far as its 
individual molecules are concerned, it follows, that the destruction 
of the spiral arrangement during the process of solution, must leave 
the chlorate of soda optically, because constitutionally, passive. 
