"alee 
British Association for the Advancement of Science. 115 
fiant gas, by the abstraction of more and more hydrogen, and the 
substitution of a corresponding quantity of chlorine, till the whole 
four atoms of hydrogen of the olefiant gas are replaced by chlo- 
rine. This view, which represents the protochloride of carbon as 
consisting of Sous atoms of carbon and four of chlorine ; or ole- 
fiant gas with its hydrogen replaced by chlorine, is consistelih 
with the observed density of its vapor. Olefiant gas, also, has 
the four atoms of carbon belonging to aleohol from which it was - 
formed, so that the protochloride of carbon has the carbon of 
alcohol from which it was primarily derived, and thus preserves, 
after numerous mutations, the most distinct traces of its ee 
2. The binary theory of the constitution of bodies, advocated by 
Liebig. This is the theoretical resolution of bodies, ap 
the most complex, into not more than two proximate constituents, ~ 
one of which, also, is generally a simple substance. There can ~ 
be no doubt that compound radicals will be the basis of the clas- 
sification of organic compounds, and that thus the same sim- 
plicity of arrangement will be introduced into organic compounds, 
as how exists in the metallic combinations of inorganic chemistry. 
A communication was read from Prof. Hare, of Philadelphia, 
on the preparation of barium, strontium and calcium. By means 
of the alternate action of two deflagrators, each of 100 pairs, 
_ containing more than 100 square inches of zinc surface, assisted 
_by refrigeration, Dr. H. has procured amalgams of these metals 
~ from their chlorides, and by distillation in an iron crucible, in- 
~ cluded in an air-tight alembic of the same metal, has extricated 
them from their mercurial solvent. (For full daseiie see this 
Journal, vol. xxxvii, p. 267.) 
Mr. Coathupe, of Bristol, described an improved method of 
graduating glass tubes for eudiometrical purposes; and also ex- 
hibited an apparatus for determining the amount of carbonic aeid 
in the atmosphere. 
The Baron Eugene Du Mesnil gave a description of a safety 
lamp invented by him in 1834. It consists of a body of flint- 
glass, defended by a dozen of iron bars. The air is admitted by 
two conical tubes, inserted at the bottom, which are capped with 
Wire-gauze, and enter by the side of the flame. The latter rises 
into a chimney, which has a piece of metal placed in the form of 
an arch over its top; the chimney being quite open. In conse- 
quence of this construction, a strong current is constantly passing . 
a 
eh 
ex 
&. Bie na 
+. ¢ 
x 
