The "Shen-nung pen ts'ao ching", a Chinese book on agriculture and medicinal plants (3rd century AD), is considered a foundational material for Chinese medicine and herbalism and became an important source for Chinese apothecaries. The book, which documented 365 treatments, had a focus on roots and grass. It had treatments which came from minerals, roots and grass, and animals. Many of the mentioned drugs and their uses are still followed today. Ginseng’s use as a sexual stimulant and aid for erectile dysfunction stems from this book. Ma huang, an herb first mentioned in the book, led to the introduction of the drug ephedrine into modern medicine.