Ijg NEW PROCESS FOR MAKING THK ARBOR DIANiE. 



XVIII. 



Letter from Mr, YiT A lis, Professor of Chemistry a^ Romn^ 

 io Mr. BouiUon-Lagrangey on the Amalgam of']\0€rcury 

 . find Siher called Arbor DiaucE*, : i 



IT . V " . •• "'' ' 



Aibor Dianz -"- ^^E process mentioned by Baurae, which is generally 

 eajiable of be- followed for obtaiiiing the peculiar amalgam ofroercurv and 

 ing taken out -, - , i ■ x u ^i x u t-» • 



ofthe'vesstfiin Silver, known m chemistry by the name oi arbor Dianae, js 



which ujs not the only one capable' of affording those beautiful crys- 

 talline tigures, that distinguish this curious production. I 

 have obtained the same object by an alteration in the com- 

 raon method, that enables me very easily to remove the me- 

 tallic arborization from the liquid in which it is formed, and 

 thus to keep it in another vessel unaltered. 

 Froeess. ^^^ process is very simple. In the nitric solutions of 



mercury and silver, both fully saturated, ard diluted with 

 the quantity of water directed by Baume, 1 suspend 5 or 6 

 drachms of very pure mercury, tied up in a piece of fiae li- 

 nen doubled. The metallic solutions soon penetrate to tlie 

 mercury enclosed in the cloth; and we presently perceive 

 clusters of beautiful needles forming round it, and adliering 

 to the nucleus of mercury. These needles gradually increase 

 in bulk, and in a short time extend above an inch in length. 

 Method of re- When the metallic arborization ceases to increase, the bag 

 moTriQgh. loaded with beautiful needly prisms, which appear to me to 

 be tetraedral, is to be taken out; and, by means of the si& 

 thread, with which it was tied up, fastened to a corlt. The 

 whole is then to be suspended under a small glass jar, in the 

 midst of which the metallic crystals may be preserved as 

 long as we please. I have a crystallization of this kind in my 

 laboratory, which has retained all its beauty these tvo years. 

 Frobably the The solidity of the metallic crystals obtained by my'me- 

 proporiions of thod, compared with the weakness of the threads that Jfbrm 

 different ^^^ comuion arbor Dianoe, lead me to suppose, that the pro<. 



portions of mercury and silver, are not the same in the two 

 cases; and I would have endeavoured to ascertain the differ- 

 ence, if Mr. Vauquelin, to whom 1 have communicated the 

 fact, had not undertaken, to remove every doubt on this 

 ■ })ead by a comparative analysis. 



• Annales de Chin*. Vol. LXir, p. 93. ^ 



The 



