In Brave New World, why is the Savage disgusted? p160: "But the Savage had suddenly broken away from his companions and was violently retching..."
In Chapter 11 Bernard, in his triumphant manner, takes John on two fields trips to show him civilization. In these episodes, Huxley's satire on the utopian world continues. At a lighting factory, as he watches each process performed by a single Bokanovsky Group, John is nauseated by the hundreds of creatures who all are the same. With bitter irony, he recalls the line of Miranda in Shakespeare's Tempest: "O brave new world that has such people in it."
This line differs now in connotation from what it meant to John when he first arrived in the New World as he was fascinated by the new civilization. Now, it turns his stomach, making him retch as he understands what has been sacrificed in the name of progress.
This episode is found in Chapter 11. The basic reason that John is retching (throwing up) is that he is completely disgusted and sickened by the sight of all the lower-caste identical twins all doing their work as if they were machines.
John has been raised on Shakespeare and on ideas of the innate value of all human life. But now he is here in "civilization" and he sees this rather inhuman sight. He cannot believe that this kind of thing can truly exist in the world. He thinks of the line from The Tempest and he is horrified at the way that this society has made human beings into crosses between animals and machines.