The extent of anæsthesia resulting varies according to the nature of the operation. Thus, if the upper part of the ganglion be spared or the operation confined to the second and third divisions, the upper lid, conjunctiva, cornea, and forehead escape. In any case, taste is but little impaired, the posterior part of the tongue being supplied by the glossopharyngeal and the tip and sides by the chorda tympani. In all cases, except perhaps in Frazier’s operation, the motor fibres which accompany the third division are almost always divided, with consequent paralysis of the corresponding masseter, temporal, and pterygoid muscles. The degree of discomfort and deformity resulting from such anæsthesia and paralysis is, however, not very considerable, and in contrast with the relief from the terrible pain, of very little import. It is, as Jonathan Hutchinson says, the price which the patient has to pay for the cure of the neuralgia. With respect to recurrence of pain, there is every reason to believe that the resection of the sensory root and the complete removal of the ganglion are never followed by recurrence of pain. With respect to Jonathan Hutchinson’s and Abbé’s operations, there is some divergence of opinion. There would appear to be some cases recorded in which the symptoms have recurred--often many years later. With regard to Hutchinson’s operation I have no personal experience, but it is stated that in some few cases the pain has recurred in the first division. I believe, however, that I am correct in stating that this is denied by Hutchinson from the experience based on his own cases. As regards Abbé’s operation, recurrence may take place if the basal foramina are not completely occluded, some few nerve fibres growing through the foramina on either side of the occluding medium. Such complications have not taken place in the cases in which I have carried out this operation. Besides experiencing immediate and complete relief from pain, the patients sleep well, eat well, and rapidly convalesce. For some two or three days they may suffer from some headache, presumably due to the necessary manipulations of the brain, but this, besides being relieved by drugs, soon passes off. Frequently, the patients are up and about within a few days. Whatever the nature of the operation, the greatest care must be taken to protect the eye on the affected side--the conjunctival sac is washed out daily with a mild boracic solution and the cornea guarded from exposure to air and dust by means of a glass covering fastened round the forehead. This appliance should be worn for two or three weeks. The =main difficulties and dangers of operation= are as follows:-- 1. Hæmorrhage (from middle meningeal artery and cavernous sinus). 2. Infection. 3. Shock. 4. Ocular complications.