According to Readers Guide to The Mahatma Letters to A. P. Sinnett:
Babula, HPB's personal servant whom she hired in Bombay soon after her arrival there. He was 15 years of age at that time and is credited with being able to speak six languages. See ML index; ODL 2: 21; LBS, pp 166-7. 
During the Coulomb controversy, Babula gave a deposition dated September 21, 1884. He stated that he had been working for Madame Blavatsky for five years; that her rooms never had any trap-doors or panels; and that Mrs. Coulomb had expressed vengeful and hateful sentiments against Mme. Blavatsky. He signed his name "Vallah Bulla" and the statement was certified by five men – William Quan Judge, Babajee Dharbagiri Nath, Damodar K. Mavalankar, Nivaran Chandra Mookerjee, and V. Coopooswamy Iyer.
- George E. Linton and Virginia Hanson, eds., Readers Guide to The Mahatma Letters to A. P. Sinnett (Adyar, Chennai, India: Theosophical Publishing House, 1972), 218.
- Vallah Bulla statement dated September 21, 1884. Adyar Committee Report, 1885, 133-134. As presented in Michael Gomes, "The Coulomb Case" Theosophical History Occasional Papers Volume X (Fullerton, California: Theosophical History, 2005) 47.