Echoes From the Gnosis – The Gnosis of The Mind is written by G. R. S. Mead the first modern scholar of Gnostic tradition. G. R. S. Mead was the secretary of H. P. Blavatsky and in 1906 he published the first volume of eleven in the series Echoes From the Gnosis. The works are a combination of translations and interpretations of ancient Gnostic writings. Long before the discovery of the Nag Hammadi Library, Mead translated these esoteric texts of various origins such as Christian and Roman.
Unfortunately, I have only been able to find six of the eleven volumes, download them here: