From Col Olcott's diary:

A letter addressed to Madam Blavatsky

Adyar, Madras
27 September 1894
My dear Madam

My Theosophical history is so nearly identical with that of the Theosophical Society, that I hardly know how to separate the two. From early manhood—say from the year 1852—I had felt an absorbing interest in the study of Practical Psychology as the master, if not the sole, Key to the mysteries of Man. I had devoted much time and my best thought to experimentation as well as to reading the best authors on the subject. I had developed clairvoyance in my first Mesmeric subject and cured my second of an inflammatory rheumatism at a single sitting. For twenty-two years, then, before meeting Helena Petrovna Blavatsky, I had been travelling the path now called Theosophical. My meeting with her, however, converted hypothesis into certainty as to the nature of 'Soul' and 'Spirit,' and that of the Elemental and other "viewless races of the air" and other kingdoms, and their relationship to humanity. First by her testimony, and next through her instrumentality, I came to know of the existence of 'Mahatmas,' the nature of their exalted 'powers,' and the system of training by which they may be evolved. Believing that the spread of such knowledge by, among other things, the vulgarisation of the contents of Oriental Literature, would be of infinite service to this generation of irreligious, or half religious, or atheistical people, and in this epoch of decaying faiths and warring moribund sects, I took advantage of a private gathering of friends at Mme. Blavatsky's rooms in the year 1875, at New York, to propose the formation of a society for carrying on this work. This organisation was decided upon, and became the Theosophical Society in due course. You ask me what work I have been engaged in. I reply that I have given my whole time during the past nineteen years to begetting, nourishing, directing and expanding the Society, until its Branches cover almost the whole Earth and its objects and ideals have been made known to nearly all nations. The strength of the Society has been derived from the Masters of Compassion, who stand behind us, its stupendous growth is due to the willing cooperation of many unselfish workers in many lands.

H. S. Olcott, P.T.S."

[Zitiert in: Murphet, Howard: Yankee beacon of Buddhist light : life of Col. Henry S. Olcott : formerly published as Hammer on the mountain. -- 1st Quest ed. --- Wheaton, Ill. : Theosophical Pub. House, 1988. -- ISBN 0-8356-0638-4. -- S. 337-339]