Intelligence and Miscellaneous Articles. 15 



tating the leaves of plants spread through five or six square feet of 

 horizontal surface. 



The author remarks, that it is evident, on inspecting the quantities 

 of gases by analysis, that they depend on the hour, the weather, the 

 season, and probably also on the latitude of the place. His analyses 

 were made at Algiers in July and August, which are there the hot- 

 test months in the year. 



Sea- water ha^'ing, hke fresh, the power of dissolving carbonic acid, 

 the author thought that this gas must act its part in the aspiration 

 and expiration of plants, but that it escaped detection by analysis on 

 account of the solvent power of the water. 



To determme this point, fresh plants with their roots were placed 

 in sea- water contained in a well- stopped bottle ; after an exposure 

 in the shade of twelve hours, it was found that the air of the bottle 

 contained a notable quantity of carbonic acid : the inverse experi- 

 ment was also made, the apparatus containing the carbonic acid was 

 placed in the sun ; the disengagement of bubbles greatly increased, 

 and a portion of carbonic acid was converted into oxygen. To dis- 

 cover whether the interior and exterior bubbles were derived from 

 gases contained in the water or from those of the plant, a leaf of an 

 ulva, containing an interior bubble, was put into a bottle of boiled 

 sea- water, the leaf having been previously washed in cold water 

 which had been boiled. The bottle was carefully stopped and ex- 

 posed to diffused light for several hours ; no bubbles were formed 

 on the exterior of the leaf, but the interior bubble increased to two 

 and a half times its size before the experiment. 



The same experiment was repeated with other leaves, and exterior 

 bubbles were collected ; but in order to succeed, the direct rays of 

 the sun must be present ; for if the disengagement be not rapid, the 

 water, deprived of air, absorbs the gas as it is liberated, and the 

 bubbles are invisible. 



It is to be observed, that in the preceding experiments the tempe- 

 rature was noted, and they were so managed as that the water pos- 

 sessed the same temperature in the shade and in the sunshine. 



Ann. de Chim. et de Phys., Aodt 1841. 



ON SOME NITROUS COMPOUNDS. 



M. Kuhlman finds that anhydrous sulphuric acid enters into di- 

 rect combination with nitric oxide, hyponitrous, nitrous and nitric 

 acid, N O 5 -)- HO, but he could not obtain a compound of anhy- 

 drous sulphuric with anhydrous nitric acid ; but the affinity of anhy- 

 drous sulphuric acid for nitric acid with an atom of water is so great, 

 that on placing nitric acid in a bottle surrounded with a coohng mix- 

 ture, and passing the vapour of the sulphuric acid into it, the va- 

 pours of nitric acid are absorbed, so that sulphuric acid is found in 

 the retort and its neck contains white crystals. 



The several anhydrous compounds appear to form also correspond- 

 ing hydrates. 



The compound of S O' et NO' -f H O subjected to distillation 



