200 Miscellanies. 



employed merely in the formation of carbonic acid in the lungs, there 

 are chemists whose results show that more oxygen is inspired than car- 

 bonic acid expired. Messrs, Allen and Pepys observed that this was 

 constantly the case when the same air was repeatedly respired. 



M. Magrms adds, that this fact, so inexplicable by other theories, is an 

 immediate consequence of the hypothesis founded on the law, that a 

 liquid holding a gas in solution parts with it when it comes in contact 

 with another gas. 



Another circumstance noticed by Messrs. Allen and Pepys is as ine:^- 

 plicable as the preceding, namely, that by the respiration of oxygen, or 

 by a mixture of oxygen and hydrogen, azotic gas is constantly expired, 

 the volume of which is proportional to the bulk of the animal; this proves 

 that it cannot at all be attributed to the air. 



It now remains to be shown that the carbonic acid extracted from the 

 blood is in sufficient quantity to account for the whole of that which the 

 lungs expire. The results obtained on this subject are discordant; those 

 of Messrs. Allen and Pepys evidently exceed what they should be ; for 

 Berzelius has shown, that if correct, it would require six pounds and a 

 quarter of solid nourishment in twenty four hours to produce the quantity 

 of carbon consumed. 



Takings then the results obtained by Davy as a mean of those of La- 

 voisier, Allen and Pepys, although perhaps a little too high, we shall 

 have thirteen cubic inches as the quantity of carbonic acid gas expired 

 by a man. If it be further admitted, that at each pulsation of the heart 

 an ounce of blood arrives at the lungs, seventy five pulsations in a minute 

 would convey five pounds of blood in the same time. This is the min- 

 imum quantity which can be admitted ; for it is very probable that five 

 pounds of blood pass through these organs every minute : these five 

 pounds produce thirteen cubic inches. It has been already mentioned 

 that the blood contains at least one fifth of its volume of carbonic acid ; 

 and as a pound is equal to twenty five cubic inches, each pound of blood 

 would contain at least five cubic inches of carbonic acid. It will be ob- 

 served that no circumstance opposes the proposed theory, hence the ex- 

 periments prove, that the quantity of carbonic acid contained in venous 

 blood, is more than sufficient to furnish the quantity expired. — Journal 

 deChimie Medicale,Nov. 1837.— Lond. and Ed. Phil. Mag. March, 1838. 



27. Eighth Meeting of the British Association for the Advancement of 

 Science. — The eighth meeting of this Institution was held at Newcastle 

 during the week from August 20 to August 26, 1838, Sir John F, W, 

 Herschel presiding. The number of members was larger than at any 

 former meeting. The Report of the doings of this meeting occupies 200 

 columns of the London Athenaeum, and contains a large amount of sci- 

 entific information, some of which we intend to transfer to the pages of 

 our next number. 



