H. Rose on a new mode of preparing Aluminium. 169 
in in aluminium is remarkably small, the metal then not having 
formed in globules, remaining in the form of a powder aud 
ing up during the cooling of the erucible.. 
»No greater gain is obtamed if the cryolite powder be iru 
fixed with a ‘part: 0 of the cart tt chlorid of potassium and 
es stratified with the sliced sodium 
But I found no gain in this wa 
I often employed, in place of chlorid of potassium, chlorid of 
~ ®odium (common table-salt heated) without observing any con- 
siderable difference in the result. Only ste heat has to be raised 
a shigher than when using chlorid of potass 
_ The operation may also be performed in Boer’ fusible omelet 
. - stone-ware crucibles of the same size as the cast iron crucibles 
,,aloresaid, Ata very high temperature they only resist with more ee 
_ difficulty the action of the fluorid of sodinm and melt in one or 
_* more places. The iron crucibles melt also, if when filled with 
; the mixture for the preparation of aluminium they are exposed to 
_ avery intense charcoal fire : 
The amount of aluminium obtained has, up to this time, been 
_ Very variable, even with the same process and the same propor- 
___ tons of materials. The quantity of metal cae in the ery- 
olite treated has never been reached. The latter contains 13 per 
cent of aluminium. By employing 10 grms. of cryolite a quan- 
tity, which was the PIE a in all experiments with the small eru- 
cibles, the most favorable product was 0:8 grm. of aluminium. If 
Wwever, only 0-6 or even 0-4 grm. were obtained out of the 13: 
grm. whic h, according to calculation were contained in the cryo- 
lite treated, the result would still be called aes mg oon 
only 0-3 grm. and less were ae ; 
so different results depend on various circumstances 
Principally however r, upon the ae of heating. The greater ae 
the heat the more the small globules unite into larger sears & ea 
the less en remains in the state of powder, bores “— 
he subsequent cooling oxydize into since Ri 
ie 1 uniting b 
_ avery great heat, in 
obtained into me si 
The heat, 
* 
«* 
- 
Pol he gas metres of the ihe ea a rate 
oOoLin 
