1814.] Royal Society* ^ :?27 



Calcium 53-313 



Fluorine 46-687 



100-000 



According to this statement, an atom of fluorine will weigli 

 2-294 (supposing an atom of calcium to weigh 2-G2*). The ana- 

 lysis of several other fluates were given, but we cannot venture to 

 state the numerical results with accuracy from memory. The 

 reader will be under no difficulty in supplying this deficiency, if he 

 considers them as compounds of an atom of fluorine and an atom 

 of the metallic bases. 



2. The second part of the paper was on silica. A. number of 

 unsuccessful attempts to obtain the base of this earth in a separate 

 state were related. They were made by passing potassium through 

 red-hot silica. Potash was obtained mixed with a brown matter, 

 which was converted into silica by tlie action of water. It would 

 appear that silica contains nearly half its weight of oxygen ; and Sir 

 H. Davy conceives it to contain 2 atoms of oxygen to I of the base. 

 This would make the weight of an atom of silicon (as we may 

 denominate that base) to be 2, nearly or almost the same with that 

 of sulphur. Sir H. Davy conceives that silicon is not a metal, but 

 analogous to boron in its nature. These bodies possess intermediate 

 properties between charcoal and sulphur. 



3. The third part of the paper was on chlorine. A number of 

 unsuccessful attempts to decompose this substance, and obtain 

 oxygen from it, were stated. Sulphuret of lead was fused in it; 

 but not the least trace of sulphate of lead could be obtained. Va- 

 rious experiments of a similar kind were tried, with an equally 

 unsuccessful result. The author noticed the scepticism still enter- 

 tained by many persons respecting the nature of chlorine, and the 

 arguments brought forward in order to show that it might contain 

 oxygen. Every candid person, he observed, who had seen the 

 combination of dry muriatic acid gas and ammoniacal gas, must be 

 convinced that no more water existed in the compound formed than 

 had previously existed in the gases. If water were really formed, it 

 would indicate rather the decomposition of azote than the existence 

 of water as a coublituent of muriatic acid. The objections of Ber- 

 zelius from the doctrine of delinite proportions are merely appa- 

 rent, as the one doctrine can he reconciled to these proportions just 

 as easily as the other. The author concluded his paper with some 

 excellent observations on the mode of reasoning in chemistry. 

 Lavoisier had tiic glory of first introducing sound logic into the, 

 science. Chemists may doubt whether there be such a thing as real 

 elements, but they are not at liberty to doubt whether a substance 

 has been decomposed or not, when all attempts to decompound it 

 have failed. Oxygen has been considered as the acidifying prin- 



• See Annali of Philosophy, vol. ii.p. 46. 



P 2 



