226 Scientific Intelligence. [Sept. 



and Passijlorea ; but does not pretend to determine absolutely to 

 which of these two famiUes it is most nearly related. 



He is inclined to consider it as being parasitical on the root to 

 which it is attached ; he does not, however, speak with confi- 

 dence even on this point, for the satisfactory determination of 

 which the examination of additional specimens in various stages 

 appears to be necessary. 



Article XII. 



SCIENTIFIC INTELLIGENCE, AND NOTICES OF SUBJECTS 

 CONNECTED WITH SCIENCE. 



I. Singular Rain. 



On Nov. 2, 1819, about half-past three in the afternoon, there 

 fell a pretty heavy shower of rain at Blankenberge, in the 

 Netherlands, which lasted about a quarter of an hour. The 

 wind was westerly. This rain had a dark-red colour. The rain 

 indeed lasted the greatest part of the day, but the red colour 

 disappeared after the interval above-mentioned, and the rain 

 assumed the ordinary appearance. Some of this extraordinary 

 rain was brought to Bruges, and examined by MM. Meyer and 

 Von Stoop, who concluded from their experiments that it owed 

 its red colour to a solution of muriate of cobalt. 



They concentrated 144 ounces to 4 ounces. No precipitate 

 fell, and no crystals made their appearance in it. When sulphu- 

 ric acid was poured into this concentrated liquid, muriatic acid 

 was driven otf in a very perceptible manner. When nitrate o' 

 silver was let fall into it, a precipitate of hornsilver immediately 

 fell. Hydrosulphuret of potash threw down a black precipitate, 

 which, when heated to redness, assumed the metallic appear- 

 ance. The liquid, after being precipitated by nitrate of silver, 

 was treated with an alkaline hydrate ; a purple-coloured precipi- 

 tate fell, which, being reduced in the usual way, gave three 

 grains of a brittle, greyish-white metal, which was attracted by 

 the magnet, and which communicated a fine blue colour to borax, 

 when treated with it before the blow-pipe. Such were the 

 evidences upon which these chemists concluded that the rain in 

 question contained muriate of cobalt. — (Gilbert's Annalen, Ixiv. 

 335.) 



II. Existence of Muriate of Potash in Rock Salt. 



M. Vogel was induced by Dr. WoUaston's discovery of the 

 existence of muriate of potash in sea water to examine whether 

 the same salt might not be detected in common salt, whether 

 obtained from mineral springs, or dug out of the earth in the 

 state of a solid water. He examined salt from Hallein and from 



