Another circumstance which distinguishes the form of sciatica which we are now describing is, the degree in which (above all other forms of neuralgia) it involves paralysis of motion. [The subject of the complication of neuralgia will be treated in a general manner farther on; but it seems necessary to note here the special liability of sciatic patients to this and to the most material complications]. By far the largest part of the motor nervous supply for the whole lower limb passes through the trunk of the great sciatic; it might therefore be naturally expected that a strong affection of the sensory portion of the nerve would produce, in a reflex manner, some powerful effect upon the motor element. This effect is most frequently in the direction of paralysis. Complete palsy is rare, but in a large proportion of cases which have lasted some time there will be found, independently of any wasting of muscles, a positive and considerable loss of motor power. It is of course necessary to avoid the fallacy which might be produced by neglecting to observe whether movement was restricted merely in consequence of its painfulness. Not long since, I had occasion to test the electric sensibility in a case of sciatica, in which there was extremely severe pain, affecting chiefly the peroneal region of the leg, and great weakness of the leg, amounting to inability for walking. The gastrocnemius could hardly be got to contract at all, when the most powerful Faradic current was directed upon the nerve in the popliteal space of the affected limb, though the muscle of the sound side reacted with great vigor. _Anæsthesia_ is also a common complication of sciatica, far commoner, I venture to think, than it has been represented either by Valleix, or Notta. It is necessary, however, to be explicit on this point. In the early stages, both of this form of sciatica, and of the milder variety previously described, there is almost always partial numbness of the skin previous to the first outbreak of the neuralgic pain, and during the intervals between the attacks. By degrees this is exchanged, in the milder form, for a generally diffused tenderness around the foci of neuralgic pain, while other portions of the limb remain more or less anæsthetic. In the severer forms it sometimes happens that, besides an intense tenderness of the skin over the painful foci, there is diffused tenderness over the greater part or the whole of the surface of the limb. But it is important to remark that both in the anæsthetic and the hyperæsthetic conditions (so called) the tactile sensibility is very much diminished. I have made a great many examinations of painful limbs, in sciatica, and have never failed to find (with the compass points) that the power of distinctive perception was decidedly lowered.