What is the primary subject and introductory story of Shri Sai Satcharitra, Chapter 34?

Chapter 34 of the Shri Sai Satcharitra continues the narration from the previous chapter on the glory and majesty of Udi (sacred ash). The introduction explicitly states that it will describe Udi's qualities and characteristics further. To illustrate this, the chapter recounts the story of a doctor from Malegaon whose nephew suffered from a terrible bone-cyst, or Hadyavran. As this chapter explains, the ailment was incurable by any conventional medical remedy, including native and foreign treatments and even surgery. This story serves as a powerful testament to the healing power of Sai Baba's Udi.