adhesions have taken place between the os uteri and posterior wall of the vagina, no trace of os uteri will be felt, and the operation above-mentioned does become sometimes necessary. _Rigidity of the os uteri._ The chief way in which the uterus can obstruct the passage of the child, is, by an undilatable state of its mouth: this may arise from a variety of causes, which may be chiefly brought under the two heads of functional and mechanical. Under the first head comes rigidity of the os uteri, either from a spasmodic contraction of its circular fibres, or from irregularity or deficiency in the contractions of the longitudinal fibres of the whole organ. In a slight degree this is frequently met with, especially in first labours, where the patient is young, delicate, and irritable, and where, in all probability, there is some source of irritation in the primæ viæ which tends to disturb and divert the proper and healthy action of the uterus. We see it also in robust plethoric primiparæ; the os uteri dilates to a certain degree, perhaps an inch in diameter, and remains tense and firm, with its edge thin; the contractions of the uterus produce much suffering, and to all appearances are very violent; but they are chiefly in front, and produce little or no effect upon its mouth; the vagina is hot and dry, the patient becomes exhausted with fruitless pains, and fever or inflammation would quickly follow, if nothing be done to relieve this state. As this subject, however, belongs rather to the next species of dystocia, viz. that arising from a faulty condition of the expelling powers, we shall delay the consideration of the treatment. _Belladonna._ It has been recommended, and not very judiciously, to apply belladonna to the os uteri in cases of great rigidity: it was repeatedly tried by the celebrated Chaussier in the Maternité, at Paris, and, according to his observations, it produced a considerable effect upon it. "The knowledge of the extraordinary powers which this drug possesses in causing dilatation of the iris, led to its employment for the object of enlarging the aperture of the uterus; but there is certainly no similarity in the structure and office of the two organs, and no analogy can be drawn between their functions. It is not likely that this means will produce the relaxation we require; and if no good results from its use, it must be injurious; not in consequence of the poisonous quality resident in the drug itself, but in the friction which is necessary for its efficient application. The mucus which naturally lubricates the part must be wiped away, and this irritation must predispose the tender organ to take upon itself inflammatory action." (_Dr. F. H. Ramsbotham's Lectures, in Med. Gaz._ May 3, 1834.)