Finally, we may observe that the relation ship of true melanic cell-pigment to the con stituents of the blood, though made the subject of much dogmatical assertion, is alto gether unknown.
The inflammatory action giving rise to the deposits which we include under the title Diphtheritic (Atotleon, a membrane), is cer tainly of special kind, though the intimate nature of its peculiarity is yet undiscovered. These deposits form on the tegumentary sur faces, mucous and cutaneous.
(a.) White Thrush (Muguet of the French). — The matter of white thrush forms on the mucous membrane of the mouth, fauces, mso phagus, and nasal passages, in patches of milky colour, cheesy consistence, variable size, and irregular form. Adhering closely to the mucous surface when first exuded, it gradu ally becomes more and more easily separable; if artificially removed, the subjacent surface looks slightly hollowed and somewhat raw, but is not abraded.
The microscope exhibits molecules ; cells of oval, spherical, or elongated form, with or without nuclei ; epithelium cells, in more or less abundance ; and fibrils. These fibrils, almost transparent, of delicate and sharply- defined outline, of cylindrical form, gene rally uniform in thickness, but sometimes swollen irregularly, and occasionally bifur cated, are not affected by water, acetic or nitric acids, or alkalies, but dissolve in sul phuric acid. Hence it appears obvious that
this substance is in part entophytie ; but it is only secondarily so,—the rapid development of fungi depending on the constitutional state, or, perhaps,upon the chemical condition, of the local secretions. The smallest cells are pro bably sporules.
There is no structural difference between the matter existing in the white thrush of children, and that appearinr, on the mucous membrane of the mouth in Zults towards the close of lingering chronic diseases, especially phthisis. But it has appeared to us from numerous observations, that it is less prone to become entophytic.
(b.) We have examined with some care the white material of cheesy consistence which forms, in certain states of the constitution, on blistered surfaces, kept open by irritant ointments, and find no particular difference between it and the similar produce of mucous membrane. Entoph3 tic formation occurs here.