The Shat-chakra-nirupana, the description of the six centres, is not a book. It is the sixth chapter of a larger Sanskrit compendium, the Sri-tattva-cintamani, which Purnananda composed in Bengal and which carries a date corresponding to 1577. The chapter sets out six centres along the spinal axis and a seventh above them, each with a number of petals, a seed syllable, a presiding deity, an element and a colour, and it describes the ascent of kundalini through them.
Tantric traditions had been describing such systems for centuries before him, and they did not agree with one another. The number of centres varies between lineages, the attributes vary, and schemes that look similar in summary turn out to overlap only in part. What Purnananda supplied was not the idea but a single tidy statement of one version of it, ordered, complete, and short enough to be handled whole.
That is what made it travel. Sir John Woodroffe, an English judge of the Calcutta High Court writing as Arthur Avalon, translated the chapter with a long introduction and published it in 1919 as The Serpent Power. That book was the principal channel through which the chakras entered Western esotericism, and the reason there appears to be one canonical chakra system rather than many is very largely the success of one translation of one chapter.