1833.] On holding the Breath for a lengthened Period. 359 



than the phenomena fairly deserve. It is this feeling which 

 makes me send for your acceptance or rejection an account of 

 an effect, new to me, and to all to whom I have mentioned it, 

 and which seems to have some valuable applications. 



At one of the scientific meetings at the apartments of His 

 Royal Highness the President of the Royal Society, whilst 

 speaking of certain men who, by means of peculiar apparatus 

 for breathing, could walk about at the bottom of waters, and 

 also of the pearl fishers, Sir Graves C. Haughton described to 

 me an observation he had made, by the application of which a 

 man could hold his breath about twice as long as under ordinary 

 circumstances. It is as follows : If a person inspire deeply, 

 he will be able immediately after to hold breath for a time, 

 varying with his health, and also very much with the state of 

 exertion or repose in which he may be at the instant. A man, 

 during an active walk, may not be able to cease from breathing 

 for more than half a minute, who, after a period of rest on a 

 chair or in bed, may refrain for a minute or a minute and a half, 

 oreven two minutes. But if that person will prepare himself 

 by breathing in a manner deep, hard and quick (as he would 

 naturally do after running), and, ceasing that operation with his 

 lungs full of air, will then hold his breath as long as he is able, 

 he will find that the time during which he can remain without 

 breathing will be double, or even more than double the former, 

 other circumstances being the same. I hope that I have here 

 stated Sir Graves C. Haughton's communication to me correctly ; 

 at all events, whilst confirming his observation by personal 

 experience, I found the results to be as above. 



Whilst thus preparing myself, I always find that certain 

 feelings come on, resembling in a slight degree those produced 

 by breathing a small dose of nitrous oxide ; slight dizziness 

 and confusion in the head are at last produced ; but on ceasing 

 to breathe, the feeling gradually goes off, no inconvenience 

 results from it either at the time or afterwards, and I can hold 

 my breath comfortably for a minute and a quarter, or a minute 

 and a half, walking briskly about in the mean time. 



Now this effect may be rendered exceedingly valuable. 

 There are many occasions on which a person who can hold 

 breath for a minute or two minutes, might save the life of 

 another. If, in a brewer's fermenting vat, or an opened cess- 



