Chemistry and Physics. 421 
of the method employed by Kupffer consists in the comparison of the 
which they term stannethyl. Tin filings are to be heated with iodid of 
ethyl in a sealed glass tube to a temperature of from 160° to 180° 
At the end of twenty-four hours the whole solidifies to a mass of large 
crystals; from this alcohol separates a substance crystallizing in long 
and brilliant needles and fusing at 38° to a limpid liquid. This sub- 
sta ‘the i , CaHsSnl, and its chemical relations 
are precisely those of the soluble metallic iodids. With nitrate and 
sulphate of silver the iodid gives crystallin 
CiHsSn0, NOs, and C4sHsSnO, SOs; 
no change even after a contact 0 
Rendus, XXXV, ) Se 
4. Preparation of Magnesium.—BunsEN has observed that fused 
chlorid of magnesium is readily decomposed by the voltaic current, so 
that it is possible in a short time, and by the emp atte 
composed of a few pairs only, to obtain a mass of metal weighing 
several grammes. For the preparation of the chlorid, Liebig’s method 
_ 18 recommended ; particular care must be taken, however, in drying the 
54 
___ Szconp Sznms, Vol. XIV, No. 42.—Nov., 1852, 
