12 5 
combinations of platinum. 
chemists respecting the composition of the known compounds 
of this valuable metal, and the circumstance of their not 
harmonizing with the doctrine of definite proportions, prove 
the necessity of submitting them to a more rigid examination ; 
and this could not be done without rendering our information 
on the bject more accurate and extensive. 
Cork Institution, 
Sept, i, 1819. 
