Spinants or spastics are medicinal substances employed to excite muscular contraction. Vegetable spinants containing the alkaloids strychnia and brucia, and employed therapeutically in cases of torpid and paralytic conditions of the muscular system, are the most important of this class ; also ergot, which is employed to excite muscular contraction of the uterus. Among the class of spinants are such agents as nux vomica, and its alkaloid strychnine, ignatia, cotton-root bark, ergot.