The ear must be placed on the Abdomen, about midway between the Pubes and the umbilicus, and towards the left side. No weight should be borne on the body, but the ear must be laid sufficiently close to exclude all external sounds, and no motion should take place, particularly with the clothes. If the sound be not heard in the position first assumed, move a little, in different directions, till that point is attained where it is most distinct. It can scarcely fail to be heard, with ordinary care. A practised ear will sometimes distinguish the sound as early as the fourth month, but generally it cannot be heard before the end of the fifth, or even till the sixth month. There are several sounds that may either be mistaken for it, or that may confuse the ear. The beating of the mother's heart will sometimes be very distinct, as far as the lower part of the Abdomen, but it is much slower; the child's heart throbbing nearly twice as fast. The movements of the Fœtus, and the rumbling of the intestines, will also interfere; but when once the proper sound has been caught it may be kept independently of all these. The manner in which the child lies in the womb will determine where the heart shall be opposite, and as its position frequently varies, both in different individuals, and at different periods, in the same person, the sound must be sought for at several points, till the right one is found. The most usual position will be seen in several of our plates, and they will give sufficient indication to enable almost any one to practise this mode of detection with success. During the early months the child moves about a good deal, so that the sound may be heard one day in one place, and the next in another. About the seventh month however, it becomes more fixed, so that the place of the heart can be pretty certainly ascertained, and thus the _position_ of the whole body is made out, whether the head is downwards or upward, and a tolerable idea can be formed even as to the direction of each part. Many persons have failed in their attempts to hear the Fœtal pulsation, but I cannot but think it must have been either from inattention, or from not being acquainted with the sound of the heart at all. I never recollect an instance when I could not do so, at the proper time. M. Chailly says he does not hesitate to affirm that in every instance they can be detected; and M. P. Dubois distinctly heard them in one hundred and eighty-five females, out of one hundred and ninety-five, in the other ten the child being probably dead. Indeed, the absence of this sound is the most certain sign of the death of the Fœtus, as its existence is of its being alive; and medical men now tell whether the child is dead or not by these very means.