Occult Science in India, by Louis Jacoilliot, , at sacred-texts.com
From noon to sunset the sacred decade was under the orders of the Master of Celestial Science, or Philosophy: from sunset to midnight it passed under the direction of the Guru of Evocations, who taught the manifested part of the occult sciences.
The Book of Spirits in our possession is silent as to the formulas of evocations taught by them. According to some Brahmins, the most fearful penalties were inflicted upon the rash man who should venture to make known to a stranger the third book of the Agrouchada, treating of those matters. According to others, these formulas were never written: they were and still are verbally communicated to the adepts, in a suppressed voice.
It is also claimed, though we have had no opportunity to verify the truth of the assertion, that a peculiar language is used to express the formulas of evocation, and that it was forbidden, under penalty of death, to translate them into the vulgar tongue. The few expressions that have come to our knowledge, such as Lrhom, Hhom, Shrhum, Shorhim, are very extraordinary and do not seem to belong to any known idiom.
The Book of the Pitris gives the following portrait of the Guru of Evocations:
The Guru of Evocations is a man who knows no other god than himself, since he has all the gods and spirits at his command." The term "gods" is here used as meaning the superior spirits. "He offers worship to Zyaus
alone, the type spirit, the primordial germ, the universal womb. At his voice, rivers and seas forsake their beds, mountains become valleys and valleys become mountains. Fire, rain, and tempests are in his service. He knows the past, the present, and the future. The stars obey him, and, armed with his seven-knotted stick, he is able to confine all the evil spirits in the universe within a single magic circle." (Agrouchada-Parikchai.)
After examining the philosophical doctrines of the believers in spirits, the Pitris, we can only study the teachings of the Guru of Evocations, in the total absence of documents, as we have already taken occasion to say, in the manifestation of occult power, or exterior phenomena, produced by his disciples, the Nirvanys and Yoguys.