Royal Insliitition. . 22 > 



duction of potassium in a different manner by Gay Lussac and 

 Thenard : and their researches with Davy's on the bases of bo- 

 racic and fluoric acids, and on the simple combustibles. The 

 accounts were next detailed of Mr. Children's battery of large 

 plates which possessed intense heating power with no electric 

 effects ; and also Mr. De Luc's and Mr. Singer's column, which 

 possessed high electrical intensity with no other power. Lastly, 

 the objections offered to Mr. Davy's hypotheses concerning oxy- 

 muriatic acid, and electro-chemical affinity, by Mr. Murray, 

 Dr. Maycock, and the author, were stated, along with Mr. Mur- 

 ray's opinion on the nature of the alkaline metalloids. 

 [To be continued in our next. J 



ROYAL INSTITUTION. 



Mr. Brande's Leclures'^. 

 Mr. Brande, in his fifth lecture on the history of chemical phi- 

 losophy, entered upon that period of his subject in which the 

 nature of the atmosphere began to attract the notice of chemists. 

 As in other branches of experimental science, so here the ad- 

 vances of the human mind had been very gradual. Mayow in 

 1674, said the professor, was upon the very brink of that tor- 

 rent of discovery, which in 1774 carried Dr. Priestley into the 

 fastnesses of pneumatic chemistry. Hales, by showing the 

 mode of disengaging and collecting gaseous fluids, had removed 

 all serious obstacles from this path of research ; he was followed 

 by Boerhaave and afterwards by Black, who, having discovered 

 fixed air, turned into another road of investigation. Although 

 tiiese philosophers, therefore, had opened the mine, they neg- 

 lected to explore it — its treasures were reserved for more diligent 

 and dexterous experimentalists. Mr. Brande then cited the 

 opinions of Libavius, Rev, MaydX\', and Hooke, respecting tht- 

 nature of the atmosphei-e, and added a I)ricf account of what h,;d 

 been done in this insulated branch of inquiry, previous to tlie 

 year 1772, when Dr. Rutherford, of li^dinburgh, demonstrated, 

 that after the separation of fixed air from that contaminated by 

 respiration and combustion, the remainder was still noxious : to 

 this new variety of air the term azote had been applied ; it was 

 also called nitrogen, it having been afterwards recognised as a 

 component part of the nitric acid. 



The discovery of azote was doubtless an important step in 

 pneumatic chemistry ; Mr. Brande passed on to that marked 

 epoch of cliemical history, which was adorned by the names of 

 Priestley, Scheele, Cavendish, and Lavoisier. 



" These discoveries," said the professor, " led to new views 



* We regret that our limits do not admit of our giving the whole of tills 

 ingenious and popiii.-ir gentleman's lectures seriatim. \Ve have therefore 

 torifincd ourselves to sucli of them as appeared of the mostgenertil interest. 



Vol. 45. No. 203. March 1815. P of 



