The Bird's Nest is the nest of seabird Jin Siyan. Most of them are built on the cliffs of tropical and subtropical islands, surrounded by rolling waves and blue sky and white clouds. Jin Siyan began to build a nest in spring. Its mouth can secrete a gelatinous saliva, which is dried by the sea breeze and turned into a translucent yellowish substance, which is the main component of bird's nest. Jin Siyan made a nest with this saliva, slender seaweed, down feathers and soft plant fibers, which is what we call a "bird's nest". Bird's nest is a precious food and a precious medicinal material. It has the effects of tonifying lung and nourishing yin, and is mainly used for treating cough and hemoptysis caused by fatigue. India, Malay Archipelago, Hainan Island and South China Sea Islands are all produced. Bird's Nest is made of mucus secreted by Jin Siyan's submandibular gland. What started out as a silky substance soon dried up and became tough and elastic. "Supplement to Compendium of Materia Medica" records that bird's nest "is sweet and flat in taste, nourishing lung yin, resolving phlegm and relieving cough, and supplementing it with clear water, which is the holy medicine for conditioning fatigue." In addition, the Compendium of Materia Medica written by Li Shizhen in the Ming Dynasty described bird's nest in detail: "In the far sea of Fujian, there are people who are famous for their golden thread. The head and tail are as small as swallows and the hair is as golden. When eggs are about to breed, birds fly to stony sand and mud to peck at silkworms and snails. Someone has consulted the sea merchants and heard that the meat on the back of silkworm snails has two tendons like maple silk, which are very strong, clean and white. Eating it can make up for the deficiency, which has caused dysentery. So the swallow ate it, but the meat turned into ribs, and the liquid spit out, forming a nest attached to the stone. For a long time, it flew with the chicks, and the sailors picked it up according to the time, so it was called bird's nest. 」