British Association for the-Adiancement of Science: 209 
By Dr. Prout’s analysis, starch sugar is CleH 0 +, or it con- 
tains an atom of water more than diabetic sugar. 
Mr. Robert Mallet read a communication on @ new case of the 
decoloration of recent solutions of Caustic Potassa of commerce, 
and on the nature of the coloring matter. The author stated, 
that the caustic potassa of commerce, was well known to be a 
very impure compound, containing besides potassa, sulphate of 
' potassa, chlorides -of potassium and i iron, peroxide. and carbonate 
of iron, silex, charcoal, and generally line, ‘He had also in one 
case found a trace of cobalt, and in several protoxide of lead, 
probably from the vessels usell in its preparation. The color of 
recent solutions of this potassa in water freed from air by boiling, 
is apple-green, and occasionally, purplish-green, which, whether 
exposed to air or not, or in dark or light, gradually disappears, 
leaving the solution ition A red precipitate of peroxide and 
carbonate of iron is produced on solution; but, after a time, the 
een solution in losing color, deposits. second in very small 
aoe: which Mr. M. has found, by analyte to consist of, 
Sesquichloride of iron, - . Ab Fu tees 
Sesquioxide of iron, ~ -. = ~ - ~Bh 2 
The decoloration of the solutions of common caustic potassa — 
was effected by violet-colored light in 30 hours, and by red in 
200 hours. z 
Mr. H. Pattinson gave an account of a new process, by him 
discovered, for the extraction of Silver from Lead. By this pro- 
cess, the details of which -are too extensive for insertion here, a 
large atnount of both lead and silver wasted by the methods now 
employed, would be. saved. 
. Dr. Golding Bird communicated “ Observations on some e of the 
Prodeaate of the action of nitric acid on .”. Numerous ex- 
periments are related in this paper, and - tlle are some of 
~ the author’s conelusions: 1..During the action of nitric acid on 
alcohol, no oxalic acid is formed as long as nitrous ether alone 
distils over. 2. Aldehyd is not produced, in any appreciable 
quantity, until oxalic acid appears in the retort, and the produc- 
tion of nitrous ether nearly ceases. - 3. During the preparation of 
nitrous ether in the eold, acetic acid is abundantly produced, and 
appears. to replace the oxalhydric. acid formed when heat i is em- 
Hoged. 
