Thomson's Sj/siem of Chemistry. 139 



appeared in the Annales, Pacchiani's second letter, confirming 

 his first statement. " This astonishing change," says he, " of 

 water into oxygenated muriatic acid, creates an agreeable sur- 

 prise in the mind ; felix qui potuit rerum copnoscere causas!" 

 In the same volume, we find the Galvanic Society of Paris 

 controverting Pacchiani's results ; which, on the other hand, 

 were affirmed by Brugnatelli *. 



The fermentation which had been thus excited in the che- 

 mical world was extreme. It was reserved for Sir H. Davy to 

 allay it, by developing the true causes of all these perplexing 

 anomalies. This he effectually accomplished in his first 

 Bakerian Lecture, " on some chemical effects of electricity," 

 read before the Royal Society in November, 1806, and pub- 

 lished in the first part of their Transactions for 1807. The ex- 

 periments detailed there were not made in a corner ; they were 

 carried on with the knowledge of some of the first philoso- 

 phers of England ; and their origin, progress, and conclusion, 

 were altogether independent of the results of Berzelius and 

 Hisinger. 



Sir H. Davy's lecture is divided into ten sections, of which 

 the first is a brief introduction ; the second developes, in a 

 masterly manner, tlie changes produced by electricity on water. 

 This research obviously furnishes the key to all his subsequent 

 discoveries ; for he finds that water electrized in contact with 

 almost any substance, mineral or orgajiic, except gold and 

 platinum, is altered by them ; and that acid and alkaline matter 

 is eliminated from substances in which nothing of that kind was 

 suspected to exist. Electricity was thus shewn to be an agent 

 of analysis, incomparably more delicate than the nicest chemical 

 tests. In his subsequent sections, he comes to infer, that it 

 may also be rendered an agent of decomposition more pouerful 

 than any hitherto known, and suggests its application to dis- 

 cover the true constituents of matter, to reach the ima pene- 

 tralia natures. " This fact," says he, " may induce us to 

 hope, that the new mode of analysis (the electrical,) may lead 

 us to the discovery of the true elements of bodies, if the ma- 

 terials acted on be employed in a certain state of concentration, 

 and the electricity be sufficiently exalted." How soon, and 

 how amply, he verified this anticipation, his discoveries of 

 potassium, sodium, calcium, barium, boron, and the chloridic 

 theory, will attest to every future age. 



Having thus endeavoured to rectify the erroneous impressions, 

 which the perusal of Doctor Thomson's account of electro-che- 

 mistry is calculated to make on the unwary reader, we proceed 

 to the second division of the first book of his system, compre- 

 licading ponderable bodies, which are handled in a very heavy 



* Sec l^hiloMpkuttl Maj^azine for Juuf, VfiOd. 



