In the context of discussing the significance of the lungs of an animal as appearing different colors – blue, black, green or red – the Gemara quotes a baraita that tells of newborn babies whose appearance is out of the ordinary.
Rabbi Natan said: ‘Once I went to the cities overseas and was approached there by a woman who, having circumcised her first son and he died and her second son and he also died, brought her third son to me. I saw that the child was red so I said to her, “My daughter, wait until the blood will become absorbed in him”. She accordingly waited and thereafter circumcised her child and he lived and was named Natan the Babylonian after me. On another occasion when I went to Cappadocia I was approached by a woman who, having circumcised her first son and he died and her second son and he also died, brought her third son to me. I saw that the child had a greenish color; I examined him and found that he was anemic, without blood for circumcision. I said to her, “My daughter, wait until the blood will circulate more freely in the child”. She accordingly waited and thereafter circumcised her child and he lived and was named Natan the Babylonian after me’.
A number of different medical explanations are offered for the conditions that these babies – who were successfully treated by means of Rabbi Natan’s advice – were suffering.
Some suggest that the children who appeared red were suffering from a rare genetic condition called neonatorum purpura.
It is likely that the children who appeared green were suffering from hemolytic jaundice of the newborn. Hemolytic jaundice is a rare, chronic, and generally hereditary disease characterized by periods of excessive hemolysis due to abnormal fragility of the red blood cells, which are small and spheroidal. It is accompanied by enlargement of the spleen and by jaundice. The hereditary form is also known as familial acholuric jaundice; there is also a rare acquired form.