184 Miscellanies. 



" A violent wind commonly increases the carbonic acid during the 

 day, in the lower strata of the air, and destroys, in whole or in part, 

 the increase of the gas during the night." 



The author's experiments were continued during several years, the 

 last noted, being on the third of January, 1830. They amounted to 

 the number of two hundred and twenty five. He found in a volume 

 of ten thousand parts of air, a minimum of about 3.06 parts, and a 

 maximum of 5.78 parts of carbonic acid. 



On the summit of the Dole, about four thousand feet above the sur- 

 face of the lake, the quantity was 4.61, while, at the same time, 

 at Chambeisy, on the plain, it was 4.74, and on another occasion 

 it was 4.91 on the mountain and 4.46 on the plain. This difference 

 is ascribed to the superior influence of vegetation on the plain, which 

 decomposes the carbonic acid, and to the greater absorption of it by 

 the streams. The greatest difierence observed at the extreme heights 

 was during a time of extraordinary humidity. — Bib. Univ. Juin, 1830. 



2. On the mutual action of iodic acid and morphine, or the acetate 

 of that base; by M. Sertjllas. — If iodic acid, in solution, at a common 

 temperature, be brought into contact with a single grain of morphine, 

 or acetate of that base, the liquid becomes of a deep red brown, and 

 exhales a strong odor of iodine. The hundredth part of a grain of 

 acetate of morphine, is sufficient to produce the effect very sensibly. 

 The action is prompt when the fluid is somewhat concentrated, slower 

 when diluted, but not less appreciable, in the lapse of a few seconds 

 even in seven thousand parts of Avater. 



Quinine, cinchonine, veratrine, picrotoxine, narcotine, strychnine, 

 and brucine, subjected to the same trial, have no action on iodic acid; 

 w^hile the smallest quantity of morphine, or its acetate, becomes evi- 

 dent in the manner just mentioned. Iodic acid may therefore be re- 

 garded as an extremely sensible reagent for detecting the presence of 

 morphine, either free or combined with acetic sulphuric, nitric or hy- 

 drochloric acid, not only isolated, but also in mixture Avith vegetable 

 alkalies, provided the latter have no action on iodic acid ; or, if they 

 have any, that it does not resemble that which morphine exerts under 

 the same circumstances. 



To render more distinct the iodine set free in the experiment, we 

 may begin by triturating with a little starch jelly, the small quantity 

 of liquid containing the morphine, or its salts, and then add a few 

 drops of the solution of iodic acid, Avhich immediately develops the 

 blue color. 



This process will serve equally well for the detection of opium, for 

 a few drops of laudanum, or of an aqueous solution of opium, min- 



