334 On definite Proportions, 



chronometer which gave the longitude of Lynn \\ 40",4 

 nuist have gone incorrectly; indeed, Mr. Wales told mc 

 that one of his watches had been within the influence of a 

 very strong magnet, in consequence of which its balance 

 was magnetical, and no great coiifidencc could be placed 

 in its ptrl'ormance. 



Lynn, April 21, 1813, Ez. WaLKER. 



LI IF. All Attempt to rleiermlne the definite and simple Pro<- 

 portions, in which the comtituevt Parts ojiinorganic Sub- 

 stances are jiniled with each other. By Jacob Berze- 

 iLivs, Professor of Medicine and Pharmaeyp and M.R.Am 

 Stockholm, 



[Continued from page 2S4.] 



Xlf. Ikon and Oxygen. 



J. HE examination of the degrees of oxidation of iron is in 

 more than one respect of great importance; its determina- 

 tion being particularly concerned in the analysis of almost 

 every mineral. Bucholz has shown by a series of very in- 

 teresting experiments, that our knowledge of this subject 

 is verv deficient, and he has endeavoured to supply the de- 

 ficiency. But he employed for his experiments common 

 bar iron, which contains a considerable portion of char- 

 coal ; and not having taken this circumstance into the ac- 

 count, his results are become erroneous. 



A. Oxide of Iron. 

 1.) I dissolved four grammes of harpsichord wire, No. 6, 

 in muriatic acid, applying a gentle heat, and collected the 

 gas evolved by means of rain water. It amounted, together 

 with the atmospherical air of the vessel, to 6Q decimal cubic 

 inches, or thousandths of a cubic foot. Tiie gas was burnt, 

 by means of an apparatus arranged for the purpose, in oxy- 

 gen, which had stood for several days over lime water, so 

 as to be freed from carb(jnic acid. During this combustion 

 of the hydrogen some carbonic acid was formed; and 

 this acid, when received in lime water, threw down a pre- 

 cipitate ol carbonaie of lime, which, when placed on a filter, 

 and dried in a heat a little above the boiling point, weighed 

 •163 gr. Now, according to my analysis, the carbonate of 

 lime contains 43*6 per cent, of carbonic acid ; consequently 

 the '\Gh gr. contained •07195 of carbonic acid, the carbon 

 cf which weighed '02 s;r. that is, \ per cent, of the weight 

 ©f the iron. The solution in the muriatic acid was greenish, 



and 



