70 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 54 



In 1845 two series of experiments were published by Gerhardt.' The 

 first, made in the usual way, gave these results: 



60.871 

 60.881 

 60.875 



Mean, 60.8757, ± .0020 



In the second series the oxygen was passed through a weighed tube 

 containing moist cotton, and another filled with pumice stone and sul- 

 phuric acid. Particles were thus collected which in the earlier series 

 escaped. From these experiments we get — 



60.947 

 60.947 

 60.952 



Mean, 60.9487, ± .0011 



These last results were afterwards sharply criticised by Marignac,^ 

 who seriously questioned their value. 



The next series, in order of time, is due to Maumene.^ This chemist 

 supposed that particles of chlorate, mechanically carried away, might 

 continue to exist as chlorate, undecomposed ; and hence that all previous 

 series of experiments might give too high a value to the residual chloride. 

 In his determinations, therefore, the ignition tube, after expulsion of the 

 oxygen, was uniformly heated in all its parts. Here are his percentages 

 of residue: 



00.788 



60.790 



60.793 



60.791 



60.785 



60.795 



60.795 



Mean, 60.791, ± .0009 



The question which most naturally arises in connection with these 

 results is, whether portions of chloride may not have been volatilized, 

 and so lost. 



Closely following Maumene's paper, there is a short note by Faget,* 

 giving certain mean results. According to this chemist, when potassium 



1 Compt. Rend., 21, 1280. 

 ^Suppl. Biblio. Univ. Geneve, Vol. 1. 

 'Ann. Chim. Phys. (3), 18, 71. 1846. 

 •• .\nn. Chim. Phys. (3), 18, SO. 1846. 



