1842.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



409 



water, it will be seen that Major-General Pasley, instead of exagge- 

 rating, lias rather restricted facts with that reserve wliicii belongs 

 only to men of real learning, who advance nothing but what they are 

 in a condition to establish beyond dispute. 



The reporter lays it down as an axiom, that one gallon of air suffices 

 to support life during one minute. I beg of him to inform us upon 

 tvhatscientific authorities he rests his reasoning. Unless he dares to 

 challenge the conclusions of the French Institute, and especially the 

 recent experiments made by Messrs. Leblanc and Dumas, it has been 

 demonstrated by the whole body of the learned, that a man inhales in 

 one hour about 200 gallons of air, and that he requires S times that 

 quantity in a shut up place, for the well-established reason tliat a 

 portion of air issuing from the bronchia, renders S portions of pure 

 air unfit for the support of life. The result from this fact is, that the 

 diving. bell of the Polytechnic Institution, containing 8U feet of cubic 

 air only, instead of 14u, as the reporter dares to affirm, or 50u gallons 

 instead of &70, a diver, without the help of my process, could not 

 remain therein more than 20 minutes. The pretended experiments 

 which are alleged to have been made subsequently to mine, and 

 which deserve to be styled mysterious far more than those to which 

 this epithet has been so injudiciously ascribed, have been witnessed 

 by no one ; and had they really taken place, as is alleged, tlie actors 

 therein must have been driven out of the diving bell by a degree of 

 suffering past endurance, whereas in ray experiments I was not sensi- 

 ble of the slightest inconvenience, and was drawn up without having 

 expressed a wish to that effect, and solely because the term allotted 

 for the experiment had expired. In a word, I can remain in the 

 diving bell an indefinite period of time. 



What would you have me answer to the absurd supposition that I 

 profess to enable a man to inhale water at the bottom of the ocean, 

 instead of air? 



The dimensions of the diving bell at Spithead are already known. 

 The cylinders, according to an exact evaluation, did not hold more 

 than 70 cubic feet of air, at a pressure of 30 in., and not 220 ft., 

 as the reporter alleges. According to the beautiful experiments of 

 Mons. Leblanc, the whole quantity of air contained in the 2 cylinders 

 and the diving bell would have been scarcely sufficient for S men 

 during one quarter of an hour. But the difficulty of living any length 

 of time under water was not the question I wished to elucidate or 

 settle at Spithead, that problem having been resolved at the Poly- 

 technic Institution. The object I had in view has been attained in 

 the most complete manner, namely, that of proving that the diving bell 

 being once filled with air, under a given pressure, it was unnecessary, 

 with the help of my process for living under water, to keep up a 

 constant supply of fresh air, for the reason, that an even pressure 

 would keep the vpater out of the diving-bell during an indefinite 

 period. These reasons alone prevented us from prolonging our con- 

 finement in the depths of the sea. 'Ihe reporter has not understood 

 them : but I can well spare his commendation, provided as I am with 

 the honourable attestations of those eminently competent gentlemen 

 who witnessed my experiments. Their testimony is, in my opinion, 

 of at least as much value as the opinions of a writer who seeks infor- 

 mation in the shop of a man who was not, as I can prove, even 

 present at the experiments in question. 



I have said enough, sir, to convince you that your reporter having 

 rested his arguments upon a foundation avowedly unsound, all his 

 conclusions are consequently erroneous, and that I had no need to at- 

 tempt to conceal a failure, in a case where I had obtained a most 

 complete success. 



Dismissing his other assertions which are not worth contradicting, 

 let us conclude that your reporter undertook a task above his reach 

 in attempting to handle a question involving principles of chemistry, 

 natural philosophy and physiology, three sciences of which he does 

 not possess the common elementary notions; and, admitting that he 

 may be less ignorant upon othtr subjects, I still cliim the privilege of 

 recommending to his notice the old adage : Ne iulor iillra cnptdum. 

 I remain. Sir, 



Yuur obedient servant. 



Dr. Payerne. 



[Ofthetoneof Dr. Payerne's letter we do not complain. He is 

 evidently smarting under the infliction of our former article, in which 

 was exposed the extravagant puffing his performances had been 

 honoured with in the newspapers; and, under the circumstances, we 

 can readily excuse his discourteous expressions. Of what we do 

 complain are, the mystifications and misstatements bv which it is 

 attempted to convey the idea that he has made some wonderful dis- 

 covery, whilst he carefully avoids mentioning explicitly what it is 

 that he claims to have discovered, and of what the nature of it con- 

 sists. It appears from the latter part of Dr. Payerne's letter, he enter- 



tains the opinion that the article commenting on his experiments was 

 w ritten by some one who " obtained his information in the shop of a 

 man who was not even present at the experiments in question." We 

 are entirely- at a loss to conceive to whom he alludes, and in this 

 respect we are as completely mystified as he could wish us to be 

 regarding the properties of his revivifying apparatus. Our comments 

 on the experiments at Spithead were, and professed to be, fou: ded 

 entirely on the report in the Timen, vihich bore the character of being 

 semi-official, and of being written by some friend of Dr. Payerne's. 

 Our object was to prove that all Dr. P. was stated to have accom- 

 plished by the aid of liis apparatus for purifying and generating air, 

 might have been done without any apparatus whatever; and to correct 

 the erroneous notions generally entertained respecting the quantities 

 of air required to sustain life in confined situations. We think we 

 completely succeeded in those objects by the statement of a few 

 simple facts and experiments ; but as Dr. Payerne now questions 

 their correctness, we must return to some of the points advanced, with 

 a view to set them at rest more conclusively. 



Dr. Payerne adduces the authority of the sarans of the ^cademie 

 dts Scieiicts against our calculations and facts respecting the quantities 

 of air necessary to support life. We are certainly not so presump- 

 tuous as to challenge all the philosophers of the French Institute, but 

 we may be allowed to question the inferences which Dr. Payerne 

 draws from their researches, in favour of his own views ; especially 

 when they can be proved to be diaiiietrically opposed to well esta- 

 blished facts. He asks on what authority we asserted that one gallon 

 of air is sufficient to support life for one minute ; and as he appears 

 to pay great deference to authorities, he may be disposed to admit 

 that the names of Messrs. Allen & Pepys deserve consideration. 

 Those accurate investigators of truth performed several experiments, 

 with a view to ascertain the quantity of air absolutely necessary 

 to support life; and the results are reported in the Plulosophicat 

 Transactions of the Royal .Society for ISOS. We did not, however, 

 state that one gallon of air per minute is sufficient for continued 

 respiration, but that life might be supported bv one gallon per minute 

 for a short period. We expressly stated that the increasing deteri- 

 oration of the air would render a larger quantity necessary, excepting 

 for a short continuance, and we made ample allowance accordingly. 

 There is no doubt that air containing a large proportion of carbonic 

 acid gas is unfit for continued respiration, but the question between 

 us and Dr. Payerne is, how long can a man ct)ntinue to respire the 

 same air without serious inconvenience ; for on that point rests the 

 value of his experiments as a test of his announced discovery. Even 

 M. Leblanc, wliose authority Dr. Payerne quotes, shows clearly that 

 the supply of air deemed desirable is far from being necesiary. In his 

 memoir read to the Acaileiny of Sciences, M. Leblanc states, rather 

 vaguely, that the quantity of air required for healthy respiration by 

 one person is from six to ten cubic metres |)er hour, yet iie mentions 

 at the same time that in the lecture room of the Sorbonne, when the 

 windows are closed, the quantity of air admitted does nut amount to 

 one cubic metre each person. But putting aside all inferences drawn 

 from analyses of the air, the claims of Dr. Payerne, which rest on hi* 

 experiments in the diving bell at the Polytechnic Institution, must be 

 annihilated if it be proved that other persons, without any apparatus, 

 have remained equally long under water in the same bell. It seems 

 that we were in error when stating the capacity of the bell to be 

 870 gallons. We have since measured it, and find its height to be 

 5 feet, and the diameter 4 feet; which give an internal capacity of 

 about 02 cubic feet, or only 3&7 gallons. The space occupied by two 

 persons cannot be estimated at less than 5 cubic feet, equal to about 

 31 gallons ; therefore the bell, when occupied by two persons, would 

 not contain more than 35(j gallons of air. This is much less than we 

 originally stated the bell to hold; and if this smaller quantity of air 

 proved sufficient to support the respiration of two persons for an hour 

 and a half, it confirms the more strongly our original ])osition respect- 

 ing the quantity of air absolutely necessary to support hfe. Dr. Pay- 

 erne feels this, therefore he denies that such an experiment could 

 have taken place, and even ventures to affirm that the "pretended 

 experiments" were witnessed by no one. The experiment icm wit- 

 nessed by a gentleman who communicated the fact to us, and on sub- 

 sequent inquiry at the Polytechnic Institution, his statement that tlie 

 parties descended, and remained in the bell without external com- 

 munication for an hour and a half, burning a candle, too, during a 

 great portion of the time, was confirmed. 



In order to remove all doubt on the subject, the Editor of this 

 Journal was determined to try the experiment himself, accordingly he, 

 accompanied by another gentleman, descended in the diving bell at 

 the West India Docks, the use of which was obligingly afforded 

 for this purpose. That bell is larger than the one at the Polytechnic 

 Institution. Its height is 4 ft. S in., length 5 ft. 8 in., and breadtli 



