 This 15-province system was gradually replaced by the 18-province system between 1662 and 1667.Using the 15-province system and the name of Kiang-nan Province indicates that the concept of China proper probably had appeared between 1645 and 1662 and this concept may reflect the idea that identifies China as the territory of the former Ming dynasty after the Qing conquest of the Ming.The concept of "China proper" also appeared before this 1795 book.