3321. Later on I was inspired to give some thought to this matter, spoken of here and there, I think, among my observations on the lung,* and indeed, what breathing out is, and what breathing in, as well as what the spontaneous kind is, and what the voluntary, that the spontaneous kind prevails at night, and the voluntary kind mixed with it by day, also that in the womb there is no breathing, but as soon as the senses need to operate, and the muscles, there is breathing. It was also said to spirits that people on earth do not know how the breathing is regulated, nor do they care to know. It is very diverse in its action: how it operates into the muscles, how it is spread, sent back, limited-even in the details of speech, which are very mysterious to mankind-also for the reason that hardly anyone pays attention to or reflects on them, not even knowing that there is a spontaneous respiration and a voluntary one, and that there is a variously mixed one during wakefulness, depending on the intensities and qualities of the body's sensations and actions. Hence it follows that there is an inner breathing when it is granted a human being to speak with spirits, which is controlled by the Lord Alone, even the angels being unaware of it. * See the author's The Animate Kingdom 385-410, and also above, nos. 366, 494-6, 1614-15, 3034 1/2.