396 LIFE OF DALTON : 



to the various phenomena of heat and cold, as produced by 

 or determining the state of other bodies ; and to the con- 

 stitution of mixed gases, and especially of those forming our 

 atmosphere. Later observations and experiments, less rude 

 than those which he employed, have tended to invalidate 

 some of his conclusions. But many yet remain untouched ; 

 all have contributed to the advancement of science; 

 and all give eminent proof of his sagacity and boldness of 

 research. 



We do not here follow the labours or writings of Dalton 

 into the great discovery of his life, as we shall speak of this 

 hereafter. Before it was sufficiently matured for publication, 

 he was invited early in 1804 to give a course of Lectures on 

 Natural Philosophy at the Eoyal Institution in London. 

 With some kind and valuable aid from Davy, he appears 

 to have gone through the course satisfactorily; and, from 

 his own account, with a good deal of applause. We cannot 

 but think, however, that he unconsciously overrated his 

 success ; and that what he considered such was but a cour- 

 teous regard of his hearers to the simplicity and peculiarities 

 of the man. A few years later, when his discoveries were 

 still only partially known, we heard him deliver a short 

 course on this subject at Edinburgh to a scanty audience. 

 It would be hard to conceive anything more uncouth 

 or ineffective than his manner of dealing with the great 

 physical truths that lay before him. His experiments, 

 as made in public, frequently failed. His voice was harsh, 

 indistinct, and unemphatical ; and he was singularly want- 

 ing in the language and power of illustration needful to a 

 lecturer on these high matters of philosophy, and by whicli 

 Davy and Faraday have given such lustre to their great 

 discoveries. Among other instances of his odd appropriation 

 of epithets, we recollect that in treating of oxygen, hydrogen, 

 nitrogen, &c. those great elements which pervade all 



