O n April 7, 1853, Queen Victoria of England gave birth to the eighth of her nine childl'en. From the beginning the infant Leopold was sickly; his baptism was postponed for almost three months. It may be that the trauma of birth had resulted in hemor­ rhages. In any event it soon became evident that he had an unusual tendency to bleed even from trivial injuries; Prince Leopold suffered from hemophil­ ia. His birth made medical history for quite a different reason: at the confine­ ment Victoria received chloroform, the anesthetic introduced by James Young Simpson of Edinburgh only six years earlier. Many were quick to see a con­ nection between hemophilia in the new­ born prince and the use of an anesthet­ ic; a bitter controversy occupied the press and the church of Victorian En­ gland. Painless childbirth was viewed by some as a defiance of the Scriptural admonition that "in sorrow thou shalt bring forth children." Hemophilia is a disease caused by a genetic defect; an individual who suf­ fers from it bleeds too freely because he cannot produce a factor in the blood that causes the plasma to coagulate. It is a sex-linked, recessive defect orig­ inally resulting from the mutation of a gene in the X chromosome of a germ cell-either the sperm of the father or the egg of the mother [see illustration on page 92]. If the child is a male, he will be hemophilic; if a female, she will be a carrier of the disease (although she will rarely suffer from it), and the chances are one out of two that her sons will be hemophilic and her daugh­ ters carriers. The sons of a hemophilic father will carry no trace of the heredi­ tary defect, since they receive his Y (and not his X) chromosome. All his daughters, however, will be carriers.