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



was to a great extent prevented from fully appreciating 

 such a theory, for instance, as th^jt of Ampere, by the 

 fact that he does not seem to have had any special talent 

 for higher mathematics. It is greatly to his credit that, 

 almost without assistance, he mastered sufficient mathe- 

 matical knowledge to lay amply that solid foundation 

 which is absolutely essential for the true scientific teach- 

 ing of every branch of physics. But he did not wield 

 the higher analysis with facility in original investigations. 

 In fact, considering the natural bent of his mind to such 

 studies as mineralogy, geology, and meteorology, it is 

 wonderful to find him so very high in the list of original 

 experimenters ; and it would not have appeared at all 

 strange had he been totally ignorant of all but the 

 elements of mathematics. 



Forbes' Correspondence (which his executors have 

 placed in my hands) cannot fail to prove, some day, of 

 very great importance to the future historian of the 

 progress of physical science, alike in this country and 

 abroad, during the last forty years. Every letter he 

 received, whether from a great master or from a mere 

 amateur observer or critic, he carefully docketed and 

 p iv served. Every letter he wrote was transferred by 

 copying ink into his letter-book. Sufficient extracts 

 from his own letters have been given in the preceding 

 chapters. Among his correspondents, not to mention 

 any still alive, we find such names as Brewster, Cauchy, 

 Ellis, Faraday, Herschel, Melloni, Murchison, Powell, 

 Eendu, Whewell, &c. &c. ; and several of them give de- 

 tailed remarks upon subjects at which he was working, or 

 which happened to form the novelty of the day. Unfor- 

 tunately, so far as this collection relates to great parts 

 of Forbes' own work, it is yet too soon to try to avail 

 ourselves of it, except in a very incomplete manner. 

 The reasons will be obvious to those who think of the 

 numerous controversies into which he was dragged. 

 For, though many extracts, and even entire letters, may 

 be selected which are free from controversy, yet in general 

 these would give but an imperfect notion of the import 



