Scientific Intelligence. 
therefore, either a mixture of olefiant-gas with a heavier and 
more combustible gas or vapour, or a new gas sui generis , con- 
sisting of hydrogen and charcoal, in proportions that remain to 
be determined. 
18. Dr lire's Dictionary of Chemistry on the Basis of Mr 
Nicholson's . — This work has been now some months before the 
public, and its reception has been so favourable, as to supersede 
the necessity of any minute detail of its composition and merits. 
The compilation of Nicholson, on whose basis the present Dic- 
tionary is founded, had become in a great measure obsolete, in 
consequence of the multitude of important discoveries made 
within the last twelve years ; and though Dr Ure seems to have 
been engaged merely to re-edite that old work, and insert occa- 
sional notices of recent improvements, he has wisely consulted 
his own reputation, in re-writing the greater part of the volume, 
which, from the style of its typography, is equivalent to at least 
three ordinary octavos. Indeed, the articles Caloric, Coal-gas, 
Combustion, Dew, Electricity, Equivalents Chemical, Gas, 
Light, inserted by the Doctor, may be regarded as more copious 
and elaborate dissertations on these leading subjects, than are to 
be found in any preceding chemical compilation. He appears 
to have taken laudable pains in ascertaining the facts which 
form the solid substratum of the science; and though the prac- 
tical nature of his work precluded much historical research, he 
has shewn in his articles Acid, Alkali, Chlorine, Congelation, 
Electricity, and Iodine, that many mistakes remain to be recti- 
fied with regard to the progress of discovery. 
III. NATURAL HISTORY. 
MINERALOGY AND GEOLOGY. 
19 Bnckland on the Structure of the Alps . — Professor Buck- 
land has just published in the Annals of Philosophy an exten- 
sive notice of a memoir on the structure of the Alps, which 
we regret has reached us too late for particular notice in our 
present Number. We shall take it up in our next. In the 
mean time, we may remark, that the statements are of a most 
interesting nature, and that the whole does infinite honour to 
the judgment of this active and enterprising geologist. 
