The tang materia medica was first book.

The Tang Materia Medica was the first pharmaceutical book.

Materia Medica is the Latin term for collected knowledge about healing substances. The Tang Materia medica was written circa 659 CE and it is one of many contributions by the Tang dynasty to science. The book, published by the then ruling Chinese government, is a compilation of drugs and instructions for their use. The book has 54 volumes, divided into 3 parts:

After it was published and distributed throughout the country by the Tang government, it became the national basis for the medical practice for more than 400 years.

the lowest among the social higher rank were the working class. this class remained detached to the political progression   of the country and was hostile to the other two classes

the use of email to replace slower surface mail.