Letters from Dr. Withering ... Dr. Ewart ... Dr. Thornton ... and Dr. Biggs ... together with some other papers supplementary to two publications on asthma, consumption, fever, and other diseases ... / By Thomas Beddoes. [Ed. by Beddoes].

  • Beddoes, Thomas, 1760-1808
Date:
1794?]
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Licence: Public Domain Mark

Credit: Letters from Dr. Withering ... Dr. Ewart ... Dr. Thornton ... and Dr. Biggs ... together with some other papers supplementary to two publications on asthma, consumption, fever, and other diseases ... / By Thomas Beddoes. [Ed. by Beddoes]. Source: Wellcome Collection.

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    lied myfelf by introducing a quantity of cauftic alkali into the bell; the air remaining after this operation was per- feftly pure oxygene air. Confidering thefe portions of air with refpeft to their weight, we fhall have for the quantities remaining under the bell after the animal had been withdrawn, the following proportions : oz. grs. grs. Oxygene air, - - 1 2 if Carbonic acid air, - 0215 1 4 i6f In this experiment the air appears to be diminifhed in bulk about i-g2d part: but its absolute weight augmented : hence it evidently refults, lft. That the air derives from the lungs during the aft of refpiration, a portion of carbonic acid air : But it mull be remarked that this augmentation of weight which appears to be only 21,87, is in reality much more confiderable than it appears to be at firft fight. The . experiment which I have juft related, produced no more than 229! inches of carbonic acid air ; now according to very exaft experiments which I have defcribed elfewhere, 100 parts of carbonic acid air in weight are compofed of 72 parts of oxygene air, and 28 of charcoal. The 22qf inches of carbonic acid air obtained in this experiment con¬ tained therefore of grains. Oxygene air, - - 114,84 Carbone, - - 44,66 The 114,84 grains of oxygene air amount in cubic inches to 22qf inches ; it then no more oxygene air had been em¬ ployed than was neceffary to form the carbonic acid air, the quantity remaining after the operation fhould have been 1728--229!=1498^ ; it was only 1443 2'3^s* the deficiency 18=54 2-3^s. It is evident from this ftatement, that independantly of the portion of oxygene air which has been converted into carbonic acid air, another portion of that which has entered the lungs has not returned in an elaftic ftate ; and it follows that one of thefe two effefts takes place during the aft of refpiration ; either that a portion of oxygene air is united with the blood, or that it is combined with a portion of kiilammable air, and compofes water. I fhall difcufs in other papers the reafons which may be adduced in favour of each of thefe opinions. But allowing, (which there is fome reafon to do) that the latter is the preferable fuppofition, it is eafy, from the above experiment, to determine the quan¬ tity of water which is formed during refpiration, and to afcertain the quantity of hydrogene extrafted from the lungs. ; ‘ In faft?