Of the power of irritation of the external genitalia to act as a so-called "exciting cause" of neuralgia, there is abundant evidence. I would especially call attention to the remarkable monograph of M. Mauriac, ["_Etude sur les Nevralgies Reflexes symptomatiques de l'Orchi-epididymite blenorrhagique_" Par C. Mauriac, Medecin de l'Hospital du Midi. Paris, 1870.] on the neuralgias consecutive to blenorrhagic orchi-epididymitis, as illustrating this with a force that was to me, for one, surprising. I shall, perhaps, have further occasion to these researches; here it will be enough to mention that M. Mauriac's enormous experience of blenorrhoea and orchitis at the Midi has shown that, in an exceedingly large number of cases, certainly not less than four per cent., this combination is followed by reflex neuralgias, of which a large number are not seated in the genital apparatus, but affect the track of some distant sensory nerve, through the intermediation of the spinal centres; and that with these reflex pains there is often profound general disturbance, including very often an extremely profound general anæmia. The most frequent kind of these neuralgias is rachialgia, _i. e._, pain in the superficial posterior branches of spinal nerves; next comes lumbo-abdominal neuralgia; then sciatic and crural, visceralgic (abdominal), etc.; and besides all these there are numerous instances of neuralgia in the testis. As to the nervous "reflection," more hereafter. It has surprised me, somewhat, that while M. Mauriac has seen so many reflex neuralgias set up by orchi-epididymitis, he does not appear to have noticed cases of trigeminal neuralgia from this source; because, in the very analogous instance of the peripheral irritation produced by excessive masturbation, we undoubtedly do frequently get a development of the tendency to migraine, and also to other forms of neuralgia of the fifth: moreover the effect of such local irritation can be occasionally traced with much distinctness in the trigemini, by a tendency to certain forms of eye-disease without positive neuralgia. This was remarkably exemplified in a case which was under my care some years ago, and in which both eyes were greatly damaged by vaso-motor and trophic changes; partial insanity also supervened with hallucinations of sight and hearing. We come now to one of the most powerful sources of peripheral irritation tending to set up neuralgia; viz., functional abuse of the eye. This is one of the very few peripheral influences which occasionally we see producing neuralgia unaided by hereditary predisposition, or any other observable cause whatever, and in a far larger number producing it with the sole aid of more or less defective general nutrition. The latter occurrence is well exemplified by a case which Mr. Carter sent me the other day, and which also illustrates (second attack) the effect of the superaddition of syphilitic taint: