Mercurius cor. has more excoriation and burning, more activity and excitement.
Mercurius is slower and more sluggish. Mercurius cor. is violent and active in its movements, it takes hold and runs its course with greater activity. So with a mercury base we have often to prefer this salt.
In the eye symptoms there is more excoriation. The pains, burning, smarting, etc., in the eruptions and ulcers are more violent. In Mercurius we have slow spreading ulcers, but in Mercurius cor. there is great eating; it will spread over an area as large as your hand in a night. He has the mercurial odor and sweat, and he is sallow; he needs mercury, but a more active preparation than Mercurius viv.
Mercurius cor. has decided symptoms of its own, but they are limited. You cannot tell the ptyalism, or the lardaceous ulcers apart.
In sore throat, if it is a Mercurius case, the ulcers are spreading rapidly and burning and smarting like coals of fire, you would say that Mercurius is not so intense as this. You need Mercurius cor. for the violence, the intense burning, and the rapid spread. The throat is enormously swollen, the glands are swollen, and the thirst is insatiable.
In dysentery there is more violence; copious bleeding; great anxiety, can scarcely leave the stool a second, great tenesmus of rectum and bladder; urging to urination and stool is constant; great burning in the rectum. It is a violent case of dysentery. I would prefer Mercurius in ordinary Mercurius cases, but if this patient is not relieved he will not live, and Mercurius cor. is needed here.
In the urinary organs the symptoms are violent. Albuminuria is more marked in Mercurius cor. than in Mercurius It is one of the most frequently indicated remedies in the albuminuria of pregnancy and a very useful remedy when gout is present.
From slight irritation of the foreskin of the male organ, the mucous membrane and skin contract and phimosis takes place.
Mercurius cor. relieves the itching and burning, and causes the purse-string to let up. It is seldom indicated in gonorrhoea, but is called for when there is greenish yellow or bloody watery discharge, with violent burning and urging to urination and to stool, and violent painful erections. Chancres spread with great rapidity.
Stitching, rending, tearing pains, here and there, especially in the chest.