In it he describes how the swiftlets 'way of building their nests with saliva is one of the wonders of the natural world, but the rich and powerful who eat the nests know nothing of the swiftlets' labors, and still less of those of the nest gatherers, so that they have no sense of the nests 'vae.
文中提到金絲燕吐涎築巢，是大自然中少有的奇觀，嗜食燕窩者既不知金絲燕的辛苦，更不知採燕人的艱辛，所以絲毫感覺不到燕窩的珍貴。