Having learned the Conception and proper Contents of the History of a Disease, we naturally proceed to another closely connected question,—do all Diseases admit of such a historical exposition? It may be taken for granted at the outset with tolerable certainty that the answer to this question will be affirmative for the majority of actual Diseases; at any rate hardly an objection can be alleged from the theoretical stand-point. At the same time practical Experience must be allowed a voice on this point. Unhappily we gain but little that is comforting from experience. It can scarcely be said that even a beginning has been made so far towards writing the History of a Disease in the indicated sense; and besides this, diseases have been primarily selected for consideration in which the historical factor obtrudes itself, as it were, on the attention, to wit the epidemic diseases. For the rest hardly anything at all has been done, excepting only in the case of Leprosy and the Venereal Disease, for which with singular unanimity an epidemic character has always been claimed. The Proteus-like character of these Maladies hindered every attempt of speculation to penetrate their nature, and so enquirers saw themselves forced to consult History. But the merest superficial glance at the treatment of Venereal disease by its Historians (and this applies equally to Leprosy) will show that little more than an insufficient collection of materials towards an actual History of the disease has thus far seen the light; and this in spite of the fact that no contemptible number of the most distinguished Scholars have devoted time and trouble to the subject, in many cases making it their life’s work. However, if the matter is looked into more closely, it will be evident that a large proportion of these scholars directed their attention to one single point only, viz. the antiquity and time of origin of the Disease; and regarded all the other factors only in so far as they supported one or other of the views they had formulated. Besides the co-ordination of these factors is seen to be so loose that no general result of any stringency could ever be obtained. The few men whose definite purpose it was to arrive at such a result, failed, in view of the difficulty of collecting the material, to reach the completeness they had proposed, and so deferred working up what they had accumulated till death put an end to their enterprise. In especial this was the case with _Hensler_, and the non-appearance of the Second Part of his History of the Venereal Disease must doubtless long continue to be mourned as an irreparable loss.