Translations and abstracts from the French. 263 



A solution of nitrate of silver, with excess of acid, is then 

 poured in so as nearly to fill the tube. When this tube is 

 placed in a plane, coincident with that of the magnetic meri- 

 dian, the precipitation of the silver and the formation of the 

 arbor diance, is abundantly more rapid than when the tube 

 is placed at right angles to the meridian, and it is more rapid 

 in the north branch than in the south, and the crystals at the 

 same time are more brilliant and more perfectly needleform. 



After the crystallization had become very manifest in the 

 north and south tube, and while little or no change had ap- 

 peared in that placed east and west, two artificial magnets 

 were placed opposite to the mercury in the latter tube, one 

 with its north pole adjacent and the other with its south pole. 

 The silver then began to appear in the usual manner. 



To give the silver greater freedom to extend itself during 

 precipitation, in a certain direction, small squares of glass 

 were procured, on which were described circles with tallow ; 

 within these a solution of silver was poured, and in the center 

 was placed a round piece of zinc. The silver immediately 

 began to form in circular zones ; but in such a manner that 

 the circles extended much more towards the north than to- 

 wards the other point of the globe. The zinc and its oxide 

 was in this case observed to incline towards the south. 



The glass plates were afterwards placed at two inches 

 distance from the pole of a strong magnet, while others were 

 placed at a distance beyond its influence. The eflfect was 

 then striking, for on the plate near the south pole of the 

 magnet, the silver was formed rapidly in that direction, and 

 the entire precipitation was effected in one fourth the time of 

 that on the plate distant from the magnet. 



These results appear to demonstrate the influence of mag- 

 netism, terrestrial and artificial, on chemical action. — Ibid. 



4. Galvanic protection by the contact of heterogeneous 

 metals. — A communication of A. Van Beek, of Utrecht, in 

 Holland to the editors of the Annales de Chimie et de Phys- 

 ique, furnishes the following remarkable examples of chem- 

 ical influence. 



1. I placed in a vase filled with sea water, a plate of cop- 

 per : the metal was promptly oxidized, and the water acquir- 

 ed in a short time a deep green color. 



2. A plate of copper, placed under the same circumstan- 

 ces, but to which I had attached a small plate of iron, tin or 



