In the number of this journal for Dec. 20, 1884, Dr. G. Frank Lydston, of Chicago, presented an interesting summary of the generalization of Dr. G. de Gorrequer Griffith, of England, "On the Unity of Poison in Scarlet, Typhoid and Puerperal Fevers, Erysipelas, Diphtheria, Sore Throats, Certain forms of Diarrhœa and Allied Affections, Pleurisy, Pneumonia, Pleuro-Pneumonia, and many other Ailments usually considered to be separate and entirely distinct Diseases," in which the author states that "by unity is meant not that the poison is always the same, but that one poison—the one origo mali—whatever it may be, will originate several so-called different affections; moreover, "that these ailments may be generated de novo, and from one common cause," as well as secondarily by contagion.
But, while it is thus recognized that there is one common poison or basic cause for a large number of apparently diverse diseases, the precise nature of