49 
Strontium the 34th, Calcium the 35th, Magnesium 
the 36th, Aluminum the 37th, Zirconum the 38th, 
Glucinum the 39th, and Ittrium the 40th of the 
undecompounded bodies, like barium, have either 
not been procured absolutely pure, or only in such 
minute quantities that their properties are little 
known ; they are formed either by electrical 
powers, or by the agency of potassium, from the 
different earths whose names they bear, with the 
change of the termination in um ; and the num- 
bers representing them are believed to be 90 stron- 
tium, 40 calcium, £9 magnesium, 33 aluminum, 
70 zirconum, 39 glucinum, 111 ittrium. 
The remaining simple bodies, are metals, most 
of which, like those just mentioned, can only be 
procured with very great difficulty ; and the sub- 
stances in general from which they are procured 
are very rare in nature. They are Palladium , 
Rhodium , Osmium , Iridium , Columbium , Chromium , 
Molybdenum , Cerium , Tellurium , Tungstenum, Ti- 
tanium, Uranium. The numbers representing these 
last bodies have not yet been determined with 
sufficient accuracy to render a reference to them 
of any utility. 
The undecompounded substances unite with 
each other, and the most remarkable compounds 
are formed by the combinations of oxygene and 
chlorine with inflammable bodies and metals ; and 
these combinations usually take place with much 
energy, and are associated with fire. 
Combustion in fact, in common cases, is the 
process of the solution of a body in oxygene, as 
happens when sulphur or charcoal is burnt ; or the 
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