Gulliver's Travels Book 3, Chapters 9-11
After a fortnight of waiting, the ship to Luggnagg is finally ready to set sail on April 21, 1709. Gulliver comes aboard with several men, and decides to speak Dutch, so that he may enter Japan, for Hollanders are the only Europeans permitted to enter the Eastern island. After the confusing voyage at sea, Gulliver arrives at Luggnagg, and speaks Balnibarbi, with a translator. The King welcomes Gulliver with generosity and lodging, and Gulliver therefore stays for three months.
On the eastern island of Luggnagg, Gulliver discovers the beautiful culture of the people - the Struldbrugg. Occasionally, a child is born with a mark over his/her left eyebrow, illustrating immortality. Gulliver is so dumbfounded by such a miracle, that he shouts with joy for this culture. He speaks in Balnibarbi to some of them and thoroughly enjoys his time there, thinking of all he would do if he were to achieve immortality. He would discover h is own happiness by discovering the differences between life and death, he would take some two hundred years to procure immense wealth and become the richest man in the kingdom, then he would devote all his time to the study of the arts and sciences so that he could become more well versed and knowledgeable than anyone else, and finally carefully observe the mannerisms of the public, the motives of the monarchy, and so on and so forth. He will not marry past threescore, and would furthermore see all the pleasures of witnessing the rise and fall of kings, queens, revolutions, monarchies, and various empires. He will find the new inventions continue to re-invent themselves, he will eventually learn the best way to run a country. He will see the advancements in astronomy and other worldly sciences. After he concludes his oral adventure into future perfection of immortality, the others erupt in laughter, for they understand the impossibility of Gulliver's ideas.
"That the system of living contrived by me was unreasonable and unjust, because it supposed a perpetuity of youth, health, and vigour, which no man could be so foolish to hope, however extravagant he might be in his wishes. That the question therefore was not whether a man would choose to be always in the primes of youth, attended with prosperity and health, but how he would pass a perpetual life under all the usual disadvantages which old age brings along with it. For although few men will avow their desires of being immortal upon such hard conditions, yet in the two kingdoms before-mentioned of Balnibarbi an Japan, he observed that every man desired to put off death for some time longer, let it approach ever so late, and he rarely heard of any man who died willingly, except he were incited by the extremity of grief or torture. And he appealed to me whether in those countries I had traveled, as well as my own, I had not observed the same general disposition." Book 3, Chapter 10, pg. 256-257
However, they inform Gulliver that the Struldbruggs are rather unfortunate people, hated by most people, and forced to live an endless life without strength and vitality. If a Struldbrugg marries another Struldbrugg, the law can dissolve the marriage when the youngest one reaches fourscore, for it doesn't seem fair to burden the man with a wife after so long a time. At eighty, they law sees them as dead, and at ninety, they lose their teeth, hair, memory, and most senses. Gulliver meets a few Struldbruggs, aghast at their horrendous appearance. Soon after meeting them, Gulliver rescinds his entire tirade of the miracle of immortality, but also realizes that these Struldbruggs may eventually rule the nation because of their lasting presence. The king suggests that Gulliver bring some Struldbruggs back to England to truncate the fear of death; however, the transport goes against both laws of England and of Luggnagg.
Gulliver leaves Luggnagg for Japan, with a kind letter of recommendation to the Japanese Emperor from the King of Luggnagg. He travels, as a Dutchman, to Amsterdam, and then returns to England, after an absence of five years and six months. He arrives on April 20, 1710, to find his wife and children happily in good health and standing.