London Philosophical Society. 225 



Mr. Davy developed some new views relative to the theory 

 of bleaching. BerthoUet, who first applied chlorine to this 

 process, supposed that chlorine destroyed colours by losing 

 its oxygen. Mr. Davy ascertained that the oxygen/ which 

 appears to be the true bleaching principle, is furnished by 

 the decomposition of the water present. Chlorine dissolved 

 in water cannot be employed in bleaching without injuring 

 the iexlure of the cloth, in consequence of the formation 

 of muriatic acid in the process. A compound of chlorine 

 and lime is commonlv employed in bleaching, but even this 

 injures the fabric of the linen. Mr. Davy has found that 

 a compound of chlorine and magnesia bleaches without 

 aflecting the vegetable fibres, and on his suggestion it has 

 been used with success by some manufacturers in Ireland. 



Chlorine combines with oxygen, and forms enchlorine. 

 Some beautiful experiments were exhibited, illustrating the 

 properties of this gas. When gently heated it was de- 

 composed with explosion, and its fine yellow colour entirely 

 destroyed. The metals, which readily burn in chlorine, are 

 not aflccted in this gas ; but at the moment of its decom- 

 position by heat, they burn vividly. 



The combinations of chlorine and hydrogen, and chlorine 

 and oxygen, harmonize with the doctrine of definite pro- 

 portions. 



These new views respecting chlorine prove the necessity 

 of attending to minute experiments, and the danger of 

 forming hasty generalizations. The ideas adopted on this 

 subject by the French School of Chemistry are entirely 

 gratuitous : every thing was taken for granted, nothing 

 proved. By using statical methods, the new truths are 

 firmly established, and improvements in theory imme- 

 diately lead to improvements in the ceconomical applica- 

 tions of Science to the purposes of the Arts. 



LONDON PHILOSOPHICAL SOCIEXy. 



This Society has been favoured with four excellent lec- 

 tures upon the Anatomy of Oratorical Expression, by Mr. 

 Wright, and which have engaged their meetings for the last 

 month. We shall endeavour to give a concise though cor- 

 rect outline of them. 



The learned author commenced his papers by observing, 

 that sensitive and inlelleciual endowments form the basis of 

 oratorical excellence; and that good understanding and 

 Solid tliought, happily blended, combine all that is useful 

 In the character of either senator, pleader, or divine. 



To |)rovc the solidity of judgement and the rectitude of 

 Vol.39. No. 167. iVia/c/i 1812. P sentiaient 



