_Duration of the first stage._ The duration of the first stage of labour varies exceedingly, both in primiparæ and those who have had several children; nor is it at all easy to determine with precision the exact moment when labour commences. The sensation of pain to the patient is no guide whatever, for what is attended with much suffering in one patient is scarcely sufficient to excite the notice of another. The dilatation of the os uteri as marking its commencement, must also be taken with some caution: in primiparæ, where it generally remains closed until the contractions are becoming painful, it would obviously be wrong to date the commencement of labour from the moment that the os uteri opens, as regular uterine contractions have been evidently present for some hours previously, although not of sufficient force to produce actual pain. On the other hand, in women who have already had several children, the os uteri is found open some days and even weeks before labour comes on. As a general rule, we may state that regular and genuine contractions of the uterus, sufficiently powerful to produce pain, seldom require more than six hours to effect the full dilatation of the os uteri; in many cases a much shorter time will be sufficient; whereas, in others, the first stage of labour may last for more than quadruple this period before it is completed: in neither can it be considered as abnormal; and we usually find that where the pains of the first stage have been slow and lingering, they become remarkably quick and active during the second stage. This agrees with the experience of Dr. Churchill, in his report of the Western Lying-in Hospital at Dublin, viz. that, "no evil consequences resulted, and they (the labours where the first stage was so protracted) were amongst those in whom the remaining stages of labour were shortest."