Dog's Mercury is a common plant with poisonous properties, on account of which it is avoided by cattle. It was proved by Hesse. Like other Euphorbians, it has exceedingly acrid properties, and many of its symptoms resemble closely those of the more corrosive salts of Mercury: prevalence of burning symptoms; irritation of eyes and nose; tenesmus after stool, &c. "Compared with other Euphorbians," says Cooper, "it dries up the mucous surfaces, causing burning locally and a general drowsiness, whilst most Euphorbians set up violent irritation and diarrhoea from the first. Moreover, its action is not expended on the skin so soon as that of the others." Among the most characteristic symptoms is "vertigo by going downstairs." The dryness of the mouth and throat is more remarkable than in any other remedy, even sugar refuses to melt in the mouth. Eating < the dryness. The breath from the mouth is hot and dries the lips. There is also hot breath in the nose, but cold breath in the nose is more characteristic. "Tension" is a leading note of the remedy running through the symptoms ("pain as of a hand tied tightly across the forehead" is a characteristic of David Wilson's); also dragging and especially dragging down; in small of back with rectal pains; in groins and thigh as if a hernia might appear. A very remarkable action is that on the female generative organs, and puts Merls. in the front rank of remedies for amenorrhoea, scanty and delayed menses, and dysmenorrhoea, accompanied with orgasm, pains, and swelling of breasts. Among the peculiar sensations are: Heaviness in head as if pressed on pillow with a weight. Numbness of head and dulness of mind. Conscious of having a nose; also I have noted (but am unable to trace the authority), "she feels as if she has two noses." Head confused as if inflated. As if intoxicated. Rolling, throbbing, trembling, and orgasm in all the veins. The liver and spleen are influenced; "warmth in spleen" is one symptom. Tension in rectum and back. Touch <. Headache < indoors, > by cold. Sunlight < eyes. Open air = blinking.