Seven to ten minutes was not chosen because it sounded elegant. It was chosen because it is the length people keep.
Every evening practice has the same failure mode. It is not that the practice does not work. It is that it is abandoned, usually inside a month, and almost always because it asked for more time than the person actually had at the end of a day. A twenty-minute ritual is a wonderful thing on a Sunday and an imposition on a Wednesday.
So the House worked backwards from adherence, and then checked that the number was long enough to be worth doing.
What happens to the breath
Sit still in front of warm aromatic air and the breath lengthens. Nobody has to be told to do it and most people do not notice it happening. Warmth slows a body, the vapour is pleasant to draw in slowly rather than quickly, and stillness does the rest.
Slow breathing is one of the better-studied things a person can do without equipment. A systematic review by Zaccaro and colleagues in Frontiers in Human Neuroscience in 2018 gathered the psychophysiological work on slow breathing and reported consistent associations with increased heart rate variability, shifts in autonomic balance, and self-reported states of calm and comfort.
The literature is about breathing, not about this product, and the House is careful to keep those separate. What the ritual does is make the slow breath easy and pleasant rather than a task, which is a smaller claim and a true one.
Nothing in the practice instructs the breath. The conditions do it, which is why it survives being repeated.
Why not three minutes
Because the descent is not instant. The first minute is settling: putting the vessel down, finding the distance, stopping. The aromatic is at its brightest and the attention is still on the day.
By the third or fourth minute the composition has moved, the opening notes have given way, and the breath has already lengthened without being asked to. That is the part worth being there for, and it has not happened yet at minute three.
Why not twenty
Two reasons, one physiological and one human.
The nose adapts. Olfactory receptors stop reporting a constant stimulus with any urgency after a few minutes, which is why you cannot smell your own house. A composition that drifts holds attention longer than a single note, but nothing holds it indefinitely, and past a certain point you are sitting in front of something you can no longer really perceive.
The second reason is the one that decides it. Twenty minutes is not kept. Ten is.
A note on what the aroma is doing
There is animal work suggesting that some of the compounds in this family act by way of the olfactory route rather than through the bloodstream. Harada and colleagues, writing in Frontiers in Behavioral Neuroscience in 2018, reported anxiolytic effects of linalool vapour in mice which disappeared when olfactory input was removed.
That is a study in mice, and we say so rather than dressing it up. It is offered as a line of enquiry, not as evidence about a person sitting in a chair in Delhi.
What the House claims
A composition that moves across the session so that it remains worth attending to. A length short enough to survive an ordinary week. Warmth, aroma, and a slow breath that arrives on its own.
That is the whole of it. Nidravati Vidhana is not a medicine, treats nothing, and is not offered for any condition. Persistent sleeplessness is a matter for a doctor. What a short practice can offer is the shape of an ending, most nights, at roughly the same hour.
Nidravati Vidhana is an aromatherapy preparation for the inhalation of vapour only. It is not a medicine, and no part of it is to be ingested.