_Book II., Chapter X._--_Bloodletting from a Vein._--Incising a vein for the purpose of drawing blood from it, is not a new procedure; but it is certainly a new thing to resort to bloodletting in almost all diseases. Again, it is an ancient custom to employ bloodletting in young subjects and in women who are not pregnant, but it is a new thing to perform this operation on infants and aged individuals, and on women approaching the period of confinement. It was the idea of the ancients that persons at the two extremes of life were not able to support this sort of treatment, and they were convinced that a pregnant woman, if subjected to the operation of bloodletting, would almost surely be confined before the completion of her time. Since then, however, experience has shown that there is no fixed rule about this matter, and that a physician should preferably regulate his course in accordance with observations of a different nature. The determining factor, for instance, is neither the age nor the pregnant state of the patient, but rather the degree of physical strength. In the case of a youth who is feeble, or of a delicate woman (aside from the question of pregnancy), it would be wrong to draw blood, for it would be robbing them of what little strength they possessed. But, in the case of a vigorous child, a robust old man, or a pregnant woman who is in good health, one need not hesitate to resort to this procedure. Nevertheless, there may arise, in connection with the operation of venesection, a number of questions which are quite likely to puzzle an inexperienced physician and perhaps lead him into error. For example, infants and old people possess as a rule diminished vigor, and the woman who is about to be confined needs all her strength for the period following delivery, both for herself and for the nourishing of the child. But the mere fact that one must give some thought to questions of this nature and must exercise prudence does not justify the immediate rejection of a method of treatment like that of venesection. For is it not the very essence of our art, not merely to consider the factors of age and the pregnant state, but also to form an estimate of that other and more important factor, viz., the patient’s strength,--be that patient an infant, an aged person, or a woman advanced in pregnancy,--and then to decide whether it is, or is not, great enough to bear the loss of blood? In deciding a question of this kind it will be necessary to distinguish between real vigor and obesity, between thinness and feebleness, etc. * * * * *