514 BIOGRAPHICAL ACCOUNT 



he passed from Dynamics immediately to Physical Astrono- 

 my. The sciences of Mechanics, Hydrodynamics, Astronomy 

 and Optics, together with Electricity and Magnetism, were the 

 subjects which his lectures embraced. Tliese were given with 

 great fluency and precision of language, and with the introduc- 

 tion of a good deal of mathematical demonstration. His man- 

 ner was grave and dignified. His views always ingenious, and 

 comprehensive, were full of information, and never more inte- 

 resting and instructive than when they touched on the history of 

 science. His lectures, however, Avere often complained of, as 

 difficult and hard to be followed, and this did not, in my opi- 

 nion, arise from the depth of the mathematical demonstra- 

 tions, as was sometimes said, but rather from the rapidity of 

 his discourse, which was in general beyond the rate at which 

 accurate reasoning can be easily followed. The singular faci- 

 lity of his own apprehension, made him judge too favour- 

 ably of the same power in others. To understand his lec- 

 tures completely, was, on account of the rapidity, and the uni- 

 form flow of his discourse, not a very easy task, even for men 

 tolerably familiar with the subject. On this account, his 

 lectures were less popular than might have been expected 

 from such a combination of rare talents as the author of 

 them possessed. This was assisted by the small number 

 of experiments he introduced, and a view that he took 

 of Natural Philosophy which left but a very subordinate 

 place for them to occupy. An experiment, he would 

 very truly observe, does not establish a general pi-oposi- 

 tion, and never can do more than prove a particular fact. 

 Hence, he inferred, or seemed to infer, that they are of no 

 wreat use in establishing the principles of science. This seems 

 an erroneous view. An experiment does but prove a particu- 

 lar 



