20 On the Nature of Alkalis and Earths. 



partly composed of lime, therefore potash contains a metallic 

 oxide. But the experiments in which magnesia and lime 

 have been Said to be produced from the fixed alkalis, have 

 been shown to be incorrect by Darracq and others ; and the 

 whole fabric falls to the ground. Mr. Kerr did not guess or 

 predict any thing. He only stated results considered by all 

 scientific chemists as mere delusions. 



I do not in the slightest degree mean to detract from the 

 merit of Mr. Kerr as an excellent translator of Lavoisier. 

 There is often ingenuity and good sense in his notes : — but 

 in the conclusion of the passage, of which the beginning is 

 quoted byO., as such an extraordinary instance of sagacity, 

 this sentence occurs, " Why should carbon, sulphur, and 

 phosphorus, not be considered as metals? — Because their 

 specific gravity, lustre, and ductility, differ from the bodies 

 called metals, which differ so much in these particular? 

 amongst themselves," — a mode of reasoning that would 

 confound all principles of classification. 



What O. says about oxygen and hydrogen being the 

 ultimate constituents of matter, is such vague declamation 

 that your sober readers will not wish to read any comments 

 on it. The dynamic philosophy of a new German school is 

 much more sublime, and more probable : that water + 

 electricity is oxygen, and water — electricity hydrogen; 

 and that the metals are water -f magnetism. 



Mere speculation can never do any harm, and is a toy 

 witK which any person has a right to amuse himself ; but 

 there is something in O.'s letter which may do harm. I 

 mean the indecorous manner in which he speaks of the ob- 

 jections of an English professor of respectability to the con- 

 clusions of M. Braconnot. 



In reading these objections, they appear to me expressed 

 in a most gentle way, and merely calculated to modify the 

 improper confidence which some persons, little acquainted 

 with experimental chemistry, had placed in these researches. 

 That all things may be composed of light, water, and air, 

 is not an assertion to be admitted on slight proof, or to be 

 implicitly confided in, in consequence of, a single labour. 

 Crell is at least as high an authority as Braconnot, and yet 



his 



