We cannot speak with any confidence of the power of silver compounds to relieve serious or chronic cases of this kind, though there are not wanting records of improvement, more or less marked, obtained under their use. Wunderlich reported seven cases of ataxy arrested in progress under 5-gr. doses, two or three times daily; while Charcot and Vulpian related five cases that had lasted respectively two, four, five, and two of them fifteen years. A pill containing 1/6 to 3/4 gr. of nitrate was given daily for from thirty-five to sixty days, and in every case, in the course of a week, improvement commenced as to sensibility, power of placing the limbs, as to sight, and especially as to lessening of pain ("Memoire sur le Nitrate," Bulletin de Therapeutique, 18G2). The report of such cases caused much sensation, but Topinard, who criticises them closely, asserts that in some the diagnosis was imperfect, and that admitting it in the others to be correct, there were unsuccessful cases to be compared with them, and many others unrecorded ("De l'Ataxie Loco-motrice," Paris, 1864). He has collected altogether twenty-eight cases, more or less favorable to the efficacy of the nitrate, and nine unfavorable; to these, he has added seventeen cases carefully noted under his own observation: commencing with 1/12 gr. daily, he continued it for ninety days, interrupting the course every eight days for a week; then 1/6 gr. was given for four months. In the first case reported, no good result was obtained, though erections recurred; at the end of the treatment the patient was worse, and the same has to be said of eleven other cases: in the remaining five there was some amelioration of symptoms. Alt-haus, on the other hand, has had, on the whole, a favorable experience with this remedy, and I believe that I have seen benefit from it in relieving the "lightning pains," and in arresting, for some time at least, disorder that was progressing, but it is no specific against locomotor ataxy.