98 THE LIFE OF JAMES D. FORBES. [CHAP. 



magnet. ... I cannot tell you what a weight is off my 

 mind since you agreed to modify your Mechanics. I 

 am so fully convinced that no inexperienced person can 

 undertake to write a good systematic text work, that I 

 had resolved that nothing should induce me to do it at 

 present. The same reason makes me very cautious in 

 offering any suggestions, which I might, on mature 

 reflection, repent of ; but if you will permit me, I should 

 like to send you my copy of your last edition, in which I 

 have marked in pencil on the margin the portions which 

 occur to me as suitable for the first volume of the two 

 into which you mean to divide it, according to the ideas 

 I have of utility in my own department. 1 trust you 

 will make every exertion to have the first volume out by 

 the middle of October ; and I hope you will induce your 

 bookseller to make the price as low as possible, whirl) 

 would much increase its utility. 1 



' August 8th, 1833. 



'. . . Any doubt as to the propriety of viewing 

 mixed mathematics as belonging to a natural philosophy 

 class is at this moment peculiarly untenable ; for the 

 whole progress of general physics is happily so fast 

 tending to a subjection to mathematical laws of that 

 department of science, that in no very long time mag- 

 netism, electricity, and light may be expected to be as 

 fully the objects of dynamical reasoning as gravitation is 

 at this present moment/ 



But while he was giving his main strength to these 

 weightier matters, which are fundamental, he did not 

 neglect the lighter accomplishments which tend to make 

 the perfect lecturer. When in London in May he took 

 lessons in elocution from Mrs. Siddons. At an earlier 

 date he had studied this art under other teaching, but 

 from the great actress he received, we may believe, some 

 finishing touches in the art of speaking. In the case of 

 many men what they learn from such instructors seems 

 to be a very doubtful gain. The clearer pronunciation 

 and more effective delivery thus acquired are bought at 



