The secondary affections which may arise as complications of neuralgia form a deeply interesting chapter in nervous pathology, and one which has only been explored in quite recent years. The excellent treatises of Valleix and Romberg, written only thirty years ago, make but most cursory and superficial mention of these complications, and do not attempt to group them in a scientific manner. The reflex convulsive movement of the facial muscles in severe tic-douloureux had of course been long observed; and Valleix added the correct observation that gastric disturbance was often secondarily provoked in facial neuralgia, thus improving greatly on the old view, which supposed that, where trigeminal neuralgia and stomach disorder coexisted, the latter must have been the antecedent and the cause of the former. Still, he did not explain the pathological connection. And as regards certain other most interesting results of neuralgia, which he could not avoid meeting with from time to time, _e. g._, lachrymation, flux from the nostril, salivation, altered nutrition of the hair, he only speaks of these as occasional phenomena, and in no way classifies them, or explains their relation to the neuralgia itself. There did exist, however, one too little known work of some years earlier date, which, though not dealing specifically with neuralgia, and though based upon the necessarily very imperfect knowledge of the functions of the nervous system prevalent in its day, had nevertheless done much to lay the foundation of a comprehensive view of the complications of neuralgia; we refer to the work of the brothers Griffin, on "Functional Affections of the Spinal Cord and Ganglionic System," published in 1834. In this most interesting treatise, the record of acute and extensive observations made in a quiet and unpretending way by two Irish practitioners, numerous examples are cited in which neuralgic affections were seen to be inseparably united with secondary affections of the most various organs, with which the neuralgic nerves could have no connection except through the centres, by reflex action. The authors, while firmly grasping the fact of the common connection of the nerve-pain and the other phenomena (convulsions, paralysis, altered special sensation, changes in secretion, changes even in the nutrition of particular tissues) with the central nerve system, were doubtless in error in thinking that they could detect the precise seat of the original malady, by discovering certain points of tenderness over the spinal column. But their facts were observed with the greatest care, and can now be interpreted more intelligently than was possible at the time. Here, for example, is a case which forestalls one of the most interesting pieces of information which more recent research has made generally known: