502 Intelligence and Miscellaneous Articles. 



During the rainy season. During the fine season. 



Carbonic acid 3*609 5-043 



Oxygen 2099*032 2103*199 



Nitrogen 7897*359 7891*758 



The greatest difference amounts consequently to r4«34 for the 

 carbonic acid and to 4*167 for the oxygen. These differences are 

 nearly the same as those which I found between the atmospheric air 

 of Paris and that of Havre, analysed under meteorological condi- 

 tions corresponding to the two seasons of South America. 



It follows that the composition of the air which we respire is the 

 same in Europe and in the New World as far as regards the oxygen 

 and the nitrogen, whether it be taken at the level of the sea or at an 

 elevation of 3000 metres ; the only difference is the amount of car- 

 bonic acid, which appears, especially on the high mountains, to be 

 somewhat greater than in the valleys and on the sea-shore. 



With respect to the analyses of the air collected on the ocean, they 

 have yielded a very interesting result. In the day-time this air con- 

 stantly contains a little more oxygen and a little more carbonic acid 

 than during the night. This difference becomes more perceptible 

 as we leave the coasts ; and it is probably owing to the solar rays, 

 which, heating the surface of the sea during the day, disengage a 

 portion of the gases which the sea-water holds in solution, and which, 

 as is well known, contains more oxygen and carbonic acid than 

 atmospheric air. 



Taking for term of comparison the samples of atmospheric air 

 collected on the Atlantic, on the same day, with the same wind, and 

 at more than 400 leagues distant from land, we find — 



At 3 A.M. At 3 P.M. 



Carbonic acid 3*346 5*420 



Oxygen 2096*139 2106*099 



Nitrogen 7900*515 7888*481 



The difference is therefore 2*074 for the carbonic acid and 9*960 

 for the oxygen in 10,000 vols, of air. 



The analyses of the abnormal air of New Granada present us 

 with results not less interesting. From time to time, once or twice 

 in the year, the atmosphere of New Granada contains an extraordi- 

 nary proportion of carbonic acid, which coincides with an appre- 

 ciable decrease of oxygen, and consequently alters the constitution 

 of the atmosphere in a very marked manner. 



The great number of volcanoes which exist in the New World, 

 and the clearing of forests which are effected every year in this 

 country, may cause these alterations. It is, in fact, during these 

 clearances that the constitution of the atmosphere experiences the 

 extraordinary changes which I have just mentioned. 



These clearings, which are effected by vast conflagrations, called 

 in the country las quernas^ produce considerable quantities of car- 

 bonic acid, which, mixing with the atmosphere, alter its composition. 

 The amount of carbonic acid which I found in this air rose in some 



