Collection recommendation [a]: Li Shizhen Shiyan's Hua Mu Paste Preface has letter species: one is listed in Stone Department (Volume 10) and the other is listed in Poultry Department (Volume 48). The Shiyan of the poultry department is also called "L Yan". Li Shizhen saltpetre: "It's a swallow with a hole in the heel and chest. It looks like a bat. It sucks milk and can fly, so it's a bird. The taste of meat, sweet and warm, can warm the abdomen and waist, tJ. Essence, marrow-boosting, qi-benefiting, origin-tracing and leek can cure colds and epidemic diseases. This kind of "rock" has been used in cherry blossoms since ancient times. At present, the "Shiyan" sold by Chinese medicine shops is the "Shiyan" of the towel stone department of Akebia. Protuberance is the name of some ancient brachiopod fossils. The most common ones are bang 1 1 one price and one printing P, and writing cil bowls with P and other harmful animals to introduce the body of IaoilliosP. Eighth, second, just like oP sPP. , ugly households. R recognition sp], t s Mao -a)olar recognition, p, etc. These fossils are somewhat like Shiyan in appearance, so they are named "Shiyan". But sometimes there are a few birds like the white land. These brachiopod fossils have thick paste and different numbers of stripes on their shells. Su Gong's "Tang Herbal Medicine" said: "There is a similar soil in the northwest of Yongzhou County, which is dug to a depth of more than ten feet, small in shape and as hard as stone. "Song and Kou Zongshuang's" Materia Medica "also said:" Ten commandments are like snail skin, color like earth, and hard as stone ". All refer to these brachiopod fossils.