Most of the writers on infant feeding until the late eighteenth century repeated the time-worn stories of character in humans, as well as in the lower animals, being transmitted by breast milk. However, as late as 1830, the highly respected Boston Medical and Surgical Journal was still perpetuating this belief, as is evident in the following quotation.1
We read, in the Spectator, of a certain very worthy man, who, having been bred with the milk of a goat, was extremely shy and timid in public, but that, nevertheless, he had frequently an hour in private, when, giving loose to his goatish propensities, he would enjoy a few frisks and capers. It is reported of Caligula, that he did not inherit his cruel and murderous disposition from either father or mother, but that his nurse was of a barbarous savage temper. Tiberius' nurse was unhappily a little too fond of tippling, and the Emperor proved a notorious drunkard. A bitch suckled a pig, which, when grown, would hunt as well as an ordinary hound; and the philosophical Phavorinus observes that, if a lamb be reared with goat's milk, or a kid with that of an ewe, the wool of the one will become hard, and the hair of the other soft. Further we may state, that, in the purest ages of Greece and Rome, this influence of the nurse in instilling her own good and bad qualities into the infant she suckled, was no less known than guarded against; and we find it particularly remarked, that, when Rome flourished as a commonwealth, "children were not suckled by mercenary nurses, but by the chaste mothers that bore them; thus were the Gracchi reared by their mother Cornelia, and Augustus by his mother Attia.