Chapter 18Experiences Associated with the Psychic · The Psychic Condition
Book 11. Part Four: The Fundamental Realisations of · Section Two: The Psychic Opening, Emergence and Transformation
What you describe shows that things are going on very well within, it is the psychic condition that is being gradually prepared as a basis for the sadhana. The special experiences of the burning of the psychic fire, descent of peace etc. are always intermittent until this basis is ready, but they help it to grow.
* It is this freedom from all ties and entire and sole turning to the Mother that is the deepest psychic condition. It is coming to you as touches of that condition from the psychic, therefore there is not yet the permanent state; but these touches prepare the future permanence.
The fire which you feel in the chest must surely be the psychic fire, for it is there that is the seat of the psychic and the fact that it burns strongly when you sit alone points to the same thing.