40j? Scientific Intelligence. 
octohedral crystals were formed on the sides of the vessel. This 
salt dissolves in three parts of water at 60 q , and may be obtained 
perfectly colourless, by repeated crystallisation. Upon analysis, 
Dr J?orchhammer found it to consist of 
Atoms. 
Persulphate of Iron, . . 41. 9& 3 
Sulphate of Ammonia, . .> 12.11 1 
Water, . 45.94 24 
Ann . of Phil. \ o). v. 
29- Boracic Acid in Tourmaline. — Mr Henry Seybert has dis- 
covered the boracic acid in the green tourmaline , from Chester- 
field, Massachusets ; in the rubellite and indicolite , from Mas- 
sachusets, and in the blach tourmalines from Haddam, Con- 
necticut, and Chester Creek, Delaware County. — Professor 
Sillimaifs Journal , vol. vi. p. 155. 
80. Varying quantity of Boracic Acid in Tourmaline.— Dr 
CJmelin of Tubingen has found, in all tourmalines which he has 
hitherto analysed, a varying quantity of boracic acid. He found 
it to be so even in the Common Schorl from Eibenstock in 
Saxony, analysed by Klaproth. The alkaline bases are a mix- 
ture of potash and soda, or of potash and lithion. Many of 
them contain a considerable quantity of magnesia. The variety 
Rubellite of Moravia, in whch Klaproth and Bucholz announced 
per cent, of soda, does not contain a trace of this alkali, 
but a, mixture of boracic acid, potash and lithion. According 
to him, the Rubellite is composed of 
Boracic Acid, - - 5.744 
Silica, - - 42.127 
Alumina, - - 36.430 
Oxide of Manganese, with a trace of Iron, 6.310 
Lime, - - 1.200 
Potash, - - 2.405 
Lithion, - - 2.043 
Volatile Matter, - - 1.313 
97.582 
81. Professor Silliman’s Additional Observations on the Fusim 
&f Carbonaceous Bodies. — Professor Silliman has lately found 
that melted charcoal has its conducting power greatly reduced 
by fusion, and that the globules of melted plumbago are as abso- 
lute nonconductors of heat as the diamond. The globules of 
