John Blofeld's notes on Taoist Breathing Arts (from the early 1930s)

John Blofeld traveled throughout the mountains of pre-Communist China and made notes on Taoist yoga and immortality practices. His book, The Secret & Sublime is essential reading for anyone interested in these practices.

Originally the objective of all Taoist forms of contemplation and yoga had probably
been identical—the union of opposites within oneself in order that the mysterious light
of the indwelling Tao might be made manifest. It was held that the indivisibility of the
One and the many and the identity of opposites could be experienced by unaided
intuition, but that quietistic contemplation, helped by breath control and other physical
yogas, was of great assistance. The breathing yogas mentioned by Chuang Tzu, were
certainly of very ancient origin and, though virtually identical with those of the
Buddhists, they had probably been arrived at independently.
The works of both religions testify to similar results—sensations of pure light shining
from within, or experiences of thunder and lightening also coming from within,
followed by the direct perception of the hitherto veiled core of consciousness. For
highly talented adepts, contemplation alone was held to be means sufficient in itself,
the various breathing and alchemical yogas being supplementary aids.
—–From Blofeld, John, The Secret and Sublime: Taoist Mysteries and Magic