According to modern medicine, an adult body contains about 200 bones. Some suggest that the body that was dissected in the Gemara’s case must have been that of a teenager, since younger people have cartilage in their joints that have not yet hardened into bone. Once adulthood is reached, this cartilage hardens into a single bone, so the number of bones appears to decrease.
In the ancient world autopsies were not ordinarily practiced, with the exception of the medical center in Alexandria, Egypt during the period of the Second Temple. The Gemara on today’s daf (=page) relates a story in which students of Rabbi Yishma’el perform an autopsy – perhaps in Alexandria – in order to determine the number of eivarim (joints or limbs) in a human body.
According to the Gemara, these students obtained the body of a prostitute who had been condemned to have her body burned. They boiled the body and dissected it, finding 252 eivarim. The Gemara discusses how to reconcile this with the traditional Rabbinic teaching that there are 248 eivarim, concluding that there are differences between the physiology of men and women.
The description of these students boiling the body in order to dissect it is unique for that time as it is not found in any contemporary medical literature from that period. Anatomical research of this type appears in literature only in the 16thcentury with the work of Andreas Vesalius. Thus, it appears that Rabbi Yishma’el’s students were doing pioneering work in this field.
There are two main halakhic issues with this type of study – there are prohibitions against desecration of the dead and of deriving benefit from the dead. With regard to both of these issues, commentaries distinguish between Jews and non-Jews and also point to the fact that the cadaver being used was, in any case, supposed to be burned. More importantly these activities were performed in order to learn and gain knowledge and there was no intention of desecration or financial benefit.