In the preceding paper we have shown that it is possible to make explicit, often quantitative, predictions concerning the behavior of homogeneous precipitating systems conforming to the lattice-hypothesis. By direct comparison of these predictions with experimental data, we shall be able to judge the degree to which the underlying theory represents the facts. Certain limitations to the quantitative application of the theory should be recalled.
Whenever precipitates of the composition r ∼ g1 are encountered, a mechanism not postulated by the lattice-hypothesis is indicated. Any assumption sufficient to account for this mechanism will imply a deviation from the equilibria developed in the general theory. Independently of this mechanism, the single assumption that antigen and antibody are multivalent leads to further deviations postulated by the restricted theory. These effects, deriving from the theory itself, are predictable, however. They are of two kinds.