_First contractions._ The first contractions of the uterus (in a state of health) are so slight as scarcely to be noticed by the patient: they create a sensation of equable pressure and general tightness round the abdomen, and during the contraction the uterus feels somewhat firmer, but they are neither attended with pain, nor do they appear at first to have any effect upon the os uteri; these precursory contractions generally come on a day or two before actual labour commences, and sometimes are felt at intervals for one or two weeks. Where the uterus has been exposed to any source of irritation, and especially where there is a disposition to rheumatic affection of this organ, they may produce much suffering and give rise to one form of what are called _false pains_, hereafter to be described. "The first contractions, says M. Leroux (_Sur les Pertes de Sang_, § 41.,) are feeble, and communicate no sensation to the patient; in order to discover them we must hold our hand upon the abdomen, and if we feel the globe of the uterus raise itself and become hard, this is a true contraction. These contractions gradually increase until they excite pain: but pain is not essential to a contraction; it depends on the distension and compression of the nerves produced by the resistance of the body upon which the uterus acts, and increases in severity in proportion to the degree of resistance and contraction." In proportion as the lower part of the uterus descends into the cavity of the pelvis, so does it exert a degree of pressure on the neighbouring parts; the capacity of the bladder and rectum is diminished; and being therefore unable to contain the usual quantity of urine and fæces, and being probably rendered more irritable by the pressure above-mentioned, the patient experiences frequent calls to pass water and evacuate the bowels, which is sometimes effected with considerable difficulty: in some instances she is obliged to lean forward, or support the abdomen, in order to take the weight of the child off the neck of the bladder before she can empty it: the same cause occasionally requires the use of the catheter, and sometimes renders the introduction of it a matter of considerable difficulty. As these various changes make their appearance, the patient becomes restless and anxious; she cannot remain long in the same posture; the slight precursory contractions which have been just described, are becoming stronger, and begin to produce a sensation of pain; the os uteri (in primiparæ) opens somewhat, its edge at first is exceedingly thin, and feels almost membranous; by degrees however it swells, grows thick and cushiony, and is now more dilatable.