Much time, however, must not be lost over these proceedings, but the child must be laid on its back, the lower part of its body well wrapped up, the chest slightly raised by a folded napkin placed under it. The two arms must then be taken firmly, raised and slowly extended on either side of the head, then brought down again and gently pressed on either side of the chest; and this movement of alternate raising and extending the arms and bringing them back again beside the chest must be repeated regularly some thirty times in the minute, thus imitating the movements of the chest in breathing. These efforts, too, must not be discontinued so long as the surface retains its warmth, and as an occasional heart-beat shows that life is not absolutely extinct; and I believe that in many instances failure is due to want of perseverance rather than to the absolute uselessness of the measure. =Premature Birth.=--In spite of very extraordinary exceptions, it may be laid down as a rule that children born before the completion of six and a half months of pregnancy do not survive. After that date, each additional week adds greatly to the chances of the child living. There is a mistaken idea, founded on a superstition connected with the number seven, that a seven-months child is more likely to survive than one born at the eighth month. But this notion is as destitute of support in fact as it is opposed to common sense, and the nearer any woman has approached the full term of forty weeks of pregnancy, the greater are the chances of her child being born alive and healthy. The premature child is by no means necessarily still-born. It breathes, but does so imperfectly, so that air does not enter all the smaller air-cells; and its voice is a whimper rather than a cry. Those changes in the heart and large vessels, which prepare, as pregnancy draws to a close, for the altered course of the blood when the child has to breathe through the lungs, are too little advanced for it to bear well the sudden alteration in its mode of being. The feebly beating heart and the not completely developed lungs seem but imperfectly to maintain the bodily heat. The glands of the stomach and intestines are not yet fit to perform digestion properly, while the muscular power is too feeble for the effort at sucking. Everything is sketched out, but to nothing has the finishing touch been put, and hence the frail machinery too often breaks down, in the endeavour to discharge its functions. It is surprising, however, with what rapidity Nature in some instances perfects the work which she has been called on prematurely to perform.