It is customary for the medical attendant, as a means of making the child move, to put his hand first in cold water, and then over the fundus of the uterus; the sensation of cold thus conveyed usually causing it to move immediately. Great care must be taken however, that other motions be not mistaken for those of the child, an error not at all uncommon. Many a female, and many a medical man also, has been deceived in this way, particularly in cases of uterine or ovarian dropsy, and tumor, and even in ordinary flatulence and hysteria. Females who much desire offspring frequently deceive themselves in this way, and it is sometimes next to impossible to convince them of their error. Some women possess the power of _imitating_ the movements of the child, with great exactness; and instances have been known where they have successfully imposed, both on their friends and medical attendants, for a long time, in this way. Mr. Dubois mentions instances of females who possessed this extraordinary power, and who, though not pregnant, used to present themselves to his class, for the pupils to _ascertain the motions of the child_. In short, this sign must not be too much relied upon, nor too confidently expected, for many females observe no fœtal motions at all till the sixth or seventh month, and even then very indistinctly. Sometimes also, after having been distinctly felt, these motions will altogether stop for a long time, and then appear again. At this time however, _Ballotment_ can begin to be practised, though it is not quite so certain as at a month later. The manner of performing this important manipulation has already been partly described, and by examining Plate XVI, and attending to the following remarks, it may be readily understood and practised. PLATE XVI. This Plate represents the mode of performing the Ballotment, to detect pregnancy. The outline of the figure is the same as in Plate I, and most of the organs are lettered the same. The index finger of the right hand is passed into the Vagina till it touches the body of the Womb, the neck being thrown back, owing to the tilting of the Fundus forward. The left hand is pressed firmly upon the Abdomen, just over the pubic bone. 1, Is the Fœtus.--2, The Placenta, connected with the Fœtus by the cord.--3, Is the index finger of the right hand, within the Vagina.--4, Is the left hand. The development of the Womb, and the change in its position, are very well represented in the Plate, and so are the alterations in some of the other organs. The manner in which the Bladder, A, is pressed out of its usual shape and size, may be seen by comparing this with Plate I. The shortening of the Vagina, and the expansion of its upper part, are also equally obvious, and the manner in which the mouth of the Womb is thrown back against the Rectum. [Illustration: Plate XVI.