Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Udagawa Y an was a 19th-century Japanese scholar of Western Studies, or "Rangaku". In 1840, he published his Introduction to Chemistry, a compilation of various scientific books in Dutch, which describes a wide range of scientific knowledge from the West. Most of the Dutch original material appears to be derived from William Henry''s 1799 "Elements of Experimental Chemistry". In particular, the book contains a very detailed description of the electric battery invented by Volta forty years earlier in 1800. The battery itself was constructed by Udagawa in 1831, and used in various experiments, including medical ones, based on a belief that electricity could help cure illnesses.