386 On ALLANITE, &e. 
I omit the 7 grains of junonium, becaufe I only detected it in 
one fpecimen of allanite. The excefs of weight in the preceding 
numbers, is to be afcribed chiefly to the carbonic acid combi- 
ned with the oxide of cerium, from which it was not complete- 
ly freed by a red heat. I have reafon to believe, too, that the 
proportion of iron is not quite fo much as 25.5 grains. For, 
in another analyfis, I obtained only 18 grains, and in a third 
20 grains. Some of the cerium was perhaps precipitated along 
with it in the preceding analyfis, and thus its weight was appa- 
rently increafed. ; ° 
