Wundt applied himself to writing a work that came to be one of the most important in the history of psychology, Principles of Physiological Psychology in 1874. This was the first textbook that was written pertaining to the field of psychology.[12] Wundt claimed that the book was "an attempt to mark out [psychology]as a new domain of science"[13] The Principles utilized a system of psychology that sought to investigate the immediate experiences of consciousness, including feelings, emotions, volitions and ideas, mainly explored through Wundt's system of "internal perception", or the self-examination of conscious experience by objective observation of one's consciousness. In 1879, at the University of Leipzig, Wundt opened the first laboratory ever to be exclusively devoted to psychological studies, and this event marked the official birth of psychology as an independent field of study. The new lab was full of graduate students carrying out research on topics assigned by Wundt, and it soon attracted young scholars from all over the world who were eager to learn about the new science that Wundt had developed.[