* 
8 Improvements in Physical Science (JAN. 
purity, being mixed with slag and with unreduced earth. To these 
metals Dr. Clarke has given the names of plutonium and strontium. 
II. NEW CLASSIFICATION OF CHEMICAL BODIES, 
The recent discoveries in chemistry have occasioned a very consi- 
derable revolution in the theory of thatscience. Whoever has paid 
sufficient attention to these improvements must be sensible that the 
present arrangement of chemical bodies is in many respects imper- 
fect and inconvenient. The undecomposed bodies at present known 
amount to about 48, all of which, except eight, are considered as 
metals. I had occasion to touch upon this subject some months ago 
in my review of Professor Jameson’s Mineralogy (Annals, viii. 136). 
and pointed out one or two alterations which appeared to me neces- 
sary. About the same time an elaborate dissertation on this subject 
by M. Ampere appeared in the Ann. de Chim. et de Phys. (i. 295, 
373; ii. 5, 105). He examines the properties of all the simple 
bodies in detail, with much acuteness and discrimination, and en- 
deavours to form them into a natural system, in which they follow 
each other according to their properties. I have not room at present 
to examine this arrangement with the minuteness which would be 
requisite in order to determine its accuracy, or to point out the 
reasons which induce me to dissent from some of his conclusions. 
I shall satisfy myself with giving the following outline of the classi- 
fication. 
The simple substances naturally subdivide themselves into three 
classes, namely, 
1, Gazotyres, or substances capable of forming permanent 
gases with each other. 
2. LEUCOLYTEs, or metals fusible below 25° Wedgewood, and 
whose oxides form colourless solutions with the colourless acids. 
3. CHROICOLYTES, or metals requiring a higher temperature for 
fusion than 25°, and whose oxides form coloured solutions in colour- 
less acids. 
Crass I. GazoryTEs. 
Genus 1. BoripEs. (From boron.) 
Bodies forming permanent Acid Gases with Phthore.* 
Sp. 1. Silicon. Sp. 2. Boron. 
Genus 2, ANTHRACIDES. (From ayvépaé.) 
Bodies combining with one of the Elements of Air when exposed to 
it at a sufficient Temperature, and forming permanent Gases with 
the other Element. 
Sp. 1. Carbon. Sp. 2. Hydrogen. 
* Phthore is the name by which M. Ampere has thought proper to distinguish 
the hypothetical body called fluorine by Sir H. Davy. 
