384 Scientific Intelligence. 
a strength as to produce a fleecy precipitate of a superb yellow 
colour. This precipitate, washed on a cloth, dissolves with ex- 
treme facility in ammonia, and gives a yellowish liquor, into 
which is poured an excess of ammonia, to discolour it entirely. 
In this liquor the goods to be dyed are plunged ; and all shades 
of yellow may be obtained, by diluting it with water. When 
the stuffs are taken out, they are colourless, but they assume 
gradually the yellow colour as the ammonia evaporates. In the 
above operation, all metallic utensils must be carefully avoided. 
The colour thus obtained is more durable thaii the material 
which is dyed. It resists all agents excepting the alkalies, and 
may be used in tapestry, velvets, and other stuffs for furniture, 
and also for painted papers. — Ann. de Chim. et de PJiys. tom. xii. 
p. 98. 
19 . ITlmine from Wood. — M. Braconnot has discovered that 
artificial ulmine may be obtained from wood, by the action of 
potash. He has found it in great abundance in turf, and in a 
variety of ligneous earths. He considers it as a constituent 
part of soot, but he could not produce it with oil. 
20. Clegg's New Method (f producing Coal-Gas. — Mr Clegg 
has contrived a new apparatus by which he can produce 25,000 
cubic feet of coal-gas from one chaldron of Newcastle Wallsend 
coal, without generating either tar or ammoniacal hquor, being 
15,000 cubic feet more than was formerly produced. The 
coal is introduced, by a mechanical process, in strata not exceed- 
ing half an inch in thickness. In this way, the retorts are kept 
at an uniform heat, and the coal is completely and rapidly de- 
composed, so that the whole of the hydrogen combines with 
the charcoal, constituting olefiant gas ; and the matter which 
usually escaped in the form of tar and ammoniacal liquor is 
perfectly decomposed. The expence of producing 50,000 
cubic feet of gas in twenty-four hours on the old plan is 
L. 3817 ; upon the new plan L. 1123 ; and the expence of 
producing an equal quantity of light from oil L. 19,010. 
21 . Cadmium. — Dr Clarke of Cambridge has discovered cad- 
mium in the radiated blende of Derbyshire. Several chemists 
in London have confirmed this discovery, and have detected the 
same metal in other ores of zinc. 
