1823.] in the Air of the Atmosphere, 99 



of the wind was such as to carry the breath and perspiration of 

 the surrounding persons away from the water, he found unques- 

 tionable traces of free acid ; they repeated the experiment again 

 on one of the high dykes near Harlingen with the same result. 

 It was observed that the colour of the litmus paper was particu- 

 larly affected, when in a dry season the sea was violently agitated. 



In order to ascertain the cause of this phenomenon. Dr. Von 

 Rossem tried an experiment by exposing a vessel full of fresh 

 sea-water to the rays of the sun, and poured, during that time, 

 water over it 5 he found in the water distinct traces of muriatic 

 acid. 



The experiments of M. Vogel and M. Kruger, which occa- 

 sioned the experiments about the volatiHsation of muriates men- 

 tioned before, were the following : In a balloon with two aper- 

 tures, one above and one below, to make draught, a small vessel 

 containing a solution of nitrate of silver was introduced, and the 

 balloon placed in a covered bathing car, of which one window 

 was open, while the wind generally blew from the land. When, 

 after 2 1 days, the small vessel was taken out, some bluish-black 

 flakes, and a white powder, were formed. The precipitate, 

 after having been washed, was digested with nitric acid, which 

 dissolved the black flakes, and left a white precipitate, which 

 was muriate of silver. 



M. Meisner tried the air at Halle not far from the brine springs, 

 but did not find any muriatic acid. 



From all these observations and experiments, the following are 

 the results : that the air near the sea-shore (the Baltic, the Ger- 

 man Ocean, and the Channel, the latter according to some 

 observations of M. Vogel), contains generally muriatic acid; its 

 quantity is increased by dry seasons, and ceases to exist in rainy 

 weather. 



Muriatic acid may be found in the atmosphere at a certain 

 distance from the sea-shore, and it there depends upon similar 

 circumstances as on the coast. It exists mostly combined in 

 form of neutral muriates, and it is highly probable that by the 

 action of air and atmospheric heat, the earthy and alkaline 

 muriates are not decomposed. Inmost of the experiments, they 

 passed over at the boiling temperature in the state of neutral 

 salts. Where muriatic acid was most decidedly found in a free 

 state at Amsterdam, it is evident that this at least was partly 

 owing to the sulphuric acid formed by the combustion of coal 

 and peat. 



