Precalculation of Certain Quantities Relating to Molecular Constants.

(A. I. Bachinsky. Molecular fields and their volumes. Izvest. Ross. Akad. Nauk No. 1, pp. 11—1917).

The calculation of molecular volume can be carried out, as the older authors did, on the basis of atomic volume. By this route, however, quantities are obtained that give a large discrepancy with reality, and only near absolute zero, as Nernst showed, can additivity be strictly observed. Bachinsky introduces a new method of calculation and assumes that each atom, on entering a molecule, contributes a definite volume not because the atom itself occupies a certain part of space, but because the bonds characterizing the affinity of the atoms determine the distances of the atoms from one another. Each single bond (for example, the bond \(H\) with \(C\)) contributes to the compound a certain definite volume; a double bond corresponds to double the volume, and a triple bond to triple; it is interesting that the benzene nucleus is not equivalent either to six or to nine single bonds. The errors in calculating molecular volumes by Bachinsky’s method are so insignificant that we must undoubtedly regard the procedures published in the present article as very important for molecular physics.

P. Lazarev.