The Cyanide of Potash is much used in photography, and being for this reason an accessible poison, numbers of cases of suicide and attempted suicide by its means have occurred. It is from the symptoms observed in such cases that a great part of the pathogenesis is built up; but it has also been proved by Lembke and others. The apoplectic and epileptic symptoms of Hydrocy. ac. were reproduced in the salt, and one very pronounced symptom was slow breathing. Loss of consciousness and vision occurred, and as consciousness and vision returned, vision was double. Strong tetanic convulsions. In one poisoning case the fingers were stretched out and spasmodically contracted. In another case, after the failure of all efforts to restore the patient (a photographer) with ether injections and repeated washings out of the stomach, he was placed in a hot bath and ice-cold water was poured over head and nape. Each time water was poured on his head, the patient drew deep inspirations, which gradually grew deeper and more regular till consciousness was restored. He complained of sharp occipital and gastric pains. Convalescence was rapid, but a general muscular weakness and impairment of speech lasted a long time (C. D. P.). The chief clinical uses recorded of K. cy. have been in epithelioma of the tongue, apoplectic and epileptic conditions, respiratory disorders, rheumatism of the joints, and neuralgias. Cattell recorded in the early volumes of the Brit. Jour. of Homoeopathy (xi. 348) several remarkable cases of neuralgia cured by K. cy. I quote them from Hering's Guiding Symptoms: "Agonising attacks of neuralgic pains between temporal regions and ciliary arch and maxilla, with screaming and apparent loss of sensibility, as if struck with apoplexy; pulse 84; face flushed." In this case the concomitants pointed to the drug. "Severe neuralgia in temporal region and left upper jaw, daily at 4 a.m., increasing till 10 and ceasing at 4 p.m.; in the interval, anorexia, fever, headache." The symptoms were < in a room; < immediately after meals (fulness); > by motion in open air. E. T. Adams (H. R., iv., 209) treated an inveterate whiskey-drinker, 55, for a swelling on the right side of the tongue, excavated so deeply that the first joint of the thumb could be laid in it. It had been pronounced cancerous. The patient could take no solid nutriment and fluids only with great pain. Under K. cy., 1/200 gr. doses, he recovered rapidly, was able to walk, and to eat dry bread and cooked beef with comparative ease. Persuaded by his former attendants to undergo operation, he died nineteen days after. Petroz was the first to give K. cy. in cases of this kind. A woman had cancerous ulcer of right side of tongue, involving the root. With a view of relieving the woman's sufferings Petroz gave her gr. 1/100 of K. cy. once in four days. In a fortnight the suffering was diminished, the tongue appeared less thick, and speech easier. In another fortnight the patient's countenance had lost its grey hue and drawn features, and she could eat a crumb of bread. The case went on to complete and permanent cure.