Before we quit the consideration of _Syncope_, we have to notice a fatal variety of that disease, which well deserves the attentive consideration of the forensic Physician, whose highest duty, let it be remembered, is the investigation of sudden death. It is described by _Mr. Chevalier_[24] under the term _Asphyxia Idiopathica_, in which the patient suddenly faints and dies; the essential circumstances of the disease evidently denote, says _Mr. Chevalier_, a sudden loss of power in the extreme vessels to propel the blood; in consequence of which the heart after having contracted, so as to empty itself, and then dilated again, continues relaxed for want of the return of its accustomed stimulus, and dies in that dilated state. On dissection all the cavities of the heart are found completely empty, and the viscus itself in a state of extreme flaccidity. SUFFOCATION. Suffocation may be defined, the destruction of life by the suspension of the function of respiration, occasioned by external violence. Unless we add “_by external violence_” we shall perceive that the definition would be far too comprehensive; and the term _Suffocation_ would be made to embrace a much wider range of subjects than its popular acceptation would allow. If the physiological views be correct which we have adopted and explained in the foregoing section, “On the causes and phenomena of sudden death,” we should be compelled, without such a protecting adjunct, to include under the history of Suffocation, not only the phenomena of Drowning, Strangling, Hanging, Smothering, and noxious inhalation, but even those of Apoplexy, fatal Intoxication, and various diseases of the brain and spinal marrow, together with the effects of a great proportion of Poisons; for by such agents death is undoubtedly occasioned through the failure of the respiratory functions.