Intelligence and Miscellaneous Articles. 335 



myself, have employed his paper in experiments on the atmo- 

 sphere, have adopted as the most probable opinion that which 

 attributes to ozone the bluish colour produced in the natural atmo- 

 sphere. The probability of this opinion does not appear to me to be 

 invalidated by the results of M. Cloez. 



Thus, — 1. At a distance from laboratories or workshops whence 

 hyponitric acid is evolved, the existence of rutilant vapours in the 

 atmosphere appears to me very improbable. Again, I do not believe 

 that the nitric acid produced by storms remains long without being 

 neutralized, either by ammonia, or by the lime of the calcareous 

 particles which float in the air in most countries ; and especially I 

 do not think that this acid exists beyond the drops of rain, the in- 

 fluence of which ]\I. Schonbein has recommended to be carefully 

 avoided. Moreover, the hypothesis of the coloration of iodized 

 starch by the nitric acid existing in the air has already been dis- 

 cussed by M. Schonbein, in consequence of observations made by 

 M. Heller at Vienna. The latter having observed the nitrification 

 of potash in the air, attributed this effect, and also the spontaneous 

 coloration of iodized starch-paper, to atmospheric nitric acid. But 

 M. Schonbein ascertained that this acid, diffused in the air in suffi- 

 cient quantity to redden litmus paper rapidly, acted but slowly upon 

 paper with iodized starch ; from which he concluded, that if the 

 natural air contains minute quantities of this acid insensible tp lit- 

 mus, they can have no action upon iodized paper. t^Blonp 



2. M. Cloez has observed the production of a blue colour in paper 

 exposed to the emanations of aromatic plants; but is it not the 

 same with regard to phosphorus ? Do we not see the oxidation of 

 this body accompanied by an appearance of ozone, when the too 

 active excess of the phosphorized vapours does not destroy the effect 

 first produced ? and do we there attribute the coloration of the paper 

 to other bodies than ozone } 



3. If light be capable of giving moist air the property of acting 

 upon ozonometric paper only in a closed space, this fact, whatever 

 interest it may possess, has no bearing upon the usual meteorolo- 

 gical observations relating to ozone. I may add, that the exposure 

 of the paper to the sun has one incontestable inconvenience, that of 

 increasing the fugacity of the colorations produced, by the too rapid 

 volatilization of the iodine. Therefore I have always recommended 

 the observers who have lent me their assistance to avoid, as a general 

 rule, the influence of the direct solar rays. — Comptes^Rendm, July 21, 

 1856, p. 162. 



NOTE ON THE ENDOSMOSE OF GASES. BY J. JAMlN. 



Dobereiner once filled a cracked bell-glass, standing in water in a 

 pneumatic trough, with hydrogen gas. Although the sides of the 

 crack were very closely pressed together, the hydrogen filtered slowly 

 through this fissure and became diffused in the atmosphere. What 

 was remarkable in this experiment is, that during the issue of the 

 hydrogen a partial vacuum was produced in the bell-glass, and that 

 the water rose several inches above the exterior level. This inter- 

 esting observation was not then carried any further, but M. Magnus 



