Long Xianxiang comes from sperm whales. Long Xianxiang, also known as Long Fuxiang, is a solid waxy combustible substance, dark gray or black in color, with its unique sweet earth smell (similar to the smell of isopropanol). The essence of Long Xianxiang is the dried product of intestinal secretion of sperm whale in physeteridae. Dry Long Xianxiang, opaque waxy rubber blocks are amber, black and brown, sometimes with colored stripes. Crisp and light, chewy and sticky like wax. The smell is slightly fishy and sweet. The specific gravity is about 0.7 ~ 0.9, the melting point is 6℃, and it can be dissolved in pure acid. When it burns, it gives off a blue flame and the fragrance is overflowing. It looks like musk, very elegant. Smoked things can keep a lasting fragrance. It is best to be dark brown, loose and tough, and it has a fragrance when burned.

Long Xianxiang was first discovered in ancient China. In the Han Dynasty, fishermen caught some wax floating objects in the sea, which were the finished products of Long Xianxiang after years of natural degradation. From a few kilograms to dozens of kilograms, it has a strong fishy smell, but it can emit a lasting fragrance after drying, and it is more fragrant after lighting, which is more fragrant than musk. Some local officials bought them and presented them to the emperor in front of treasures, which were used as spices or medicines in the palace. At that time, no one knew what this treasure was, so they asked the alchemist in the palace. They thought it was the saliva that the "dragon" in the sea shed when sleeping, and it dripped into the sea and solidified. After a long time, it becomes "Long Xianxiang". It is also said that in the Shang and Zhou dynasties, people mixed dragon saliva, musk and plant spices to make sachets and hung them on the bedside or body.