COMPOSITION OF THE ATMOSPHERE. 



35 



Hospitals. 



1 



Rooms. 



Oxygen. 



Carbonic 

 acid. 



Hospital ge- 

 neral 



Hospital de J 

 la Princesa 1 



20-58 



20'50 



20-49 

 20-65 

 20-52 

 20-6o 



0-32 

 0-38 



0-43 

 0-27 

 0-30 

 0-29 



The experiments of Mr. Lewy on the Atlantic Ocean and 

 in America show a great irregularity. They are given on 

 pages 6 and 7. We do not see clearly why there should 

 be a rise in the carbonic acid from '0333 to "0577 ^^ ^^a. 

 The great inequalities on the land are interesting, and 

 especially at Bogota^ where meteorological influences in- 

 terfere to render the amount great and diminish health. 



Dalton had made experiments on the atmosphere with 

 lime-water, but by no means such as are satisfactory. Mr. 

 Hadfield, who had learned in his school, improved the pro- 

 cess very much. He used a bottle of 471-498 cub. in., 

 fitted with a cap and stop -cock, and filled it by means of a 

 bellows. He tested the lime-water with sulphuric acid, 

 before and after shaking with the air, or after it had stood 

 for some days. He obtained 0"8o vol. per 1000. This is 

 high as a constant result ; but as he lived on the borders of 

 a putrid canal at Cornbrook, it may not be too high. His 

 results are found in the ' Memoirs of the Literary and Philo- 

 sophical Society of Manchester,^ 2nd series, vol vi., 1842. 



Dr. Boswell E-eid^ made trials with various amounts of 

 carbonate of lime in water, as indications of the carbonic 

 acid absorbed. After passing the air through a solution, 

 he compared the result with these trials, keeping the pre- 

 cipitates in bottles. This use of lime he called a carbono- 



* ' Ilkistrations of the Theory and Practice of Ventilation,' by David 

 Boswell Eeid, M.D., F.E.S.E., &c. : Longman, 1844. 



Ji2 



