138 Analysis of Scientific Books. 



the theatre of the Tloyal Institution," by Sir H. Davy. This 

 paper contains an immense number of ingenious views, which 

 he has since expanded and verified. " When our galvanic in- 

 struments," says he, " are rendered more perfect and more 

 powerful, we may be readily enabled by means of them, to pro- 

 cure the pure metals." Another curious discovery there an- 

 nounced by him, is " a method of constructing simple and com- 

 pound galvanic combinations, without the use of meto^/ic sub- 

 stances, by means of charcoal and different fluids." This dis- 

 covery constitutes at the present day, the most singular and 

 mysterious part of Voltaic electricity. 



The circumstances which led Sir H. Davy to institute, in 

 1806, those electro-chemical researches, which were destined 

 to enlarge the boundaries of science, to extend the empire of 

 man over the domain of matter, and to shed new glory over the 

 country of Newton, are sufficiently known to all scientific men, 

 and to no person- better than the compiler before us. In 

 the Philosophical Magazine for April, 1805, a short letter 

 was inserted, dated Cambridge, and signed \V. Peel, in- 

 timating, that by the galvanic decomposition of distilled 

 water, he had generated muriate of soda. The Edinburgh Me- 

 dical and Surgical Journal of the following July, contains a 

 letter from Professor Pacchiani, bearing date, Pisa, May 9th, 

 1805, in which he announces, that he has succeeded by gal- 

 vanism, in proving muriatic and oxymuriatic acids to be oxides 

 of hydrogen ; but that, in the latter, there is less oxygen than 

 exists in water ; or, as he states it afterwards in a new letter 

 to Fabroni, " In short, all substances proper for decomposing 

 water, as soon as they are traversed by an electrical current 

 strong enough to disengage oxygen, have the property of con- 

 verting water into oxygenated muriatic acid *. In the Philo- 

 sophical Magazine for July, 1805, we find another letter, signed 

 W. Peel, announcing that, on repeating his experiment on 

 water, he obtained muriate of potash, instead of muriate of 

 soda. In the same number, Dr. Henry inserted a letter, shew- 

 ing, that muriatic acid was produced by the electrization of 

 distilled water, with platina points, in a glass tube. To this 

 letter the editor subjoins a judicious note, in which he says, 

 " From all that has yet occurred on this subject, a strong pre- 

 sumption is furnished, that we are on the verge of, perhaps, 

 more than one important discovery in chemistry," a predic- 

 tion soon verified by Sir H. Davy. A third letter, signed 

 W. Peel, is printed in the Philosophical Magazine for December, 

 1805, in which it is asserted, that doubly-distilled snow-water, 

 yielded by galvanism, muriate of soda. About the same time 



* Annales ie Chimie, torn. LVI. ; or, Tillock's Magazine for March, 

 180«. 



