LAVOISIEK. 291 



searches. It is, moreover, both a debt of gratitude to 

 our benefactors which we should be anxious to pay by 

 testifying our gratitude, and commemorating their 

 fame ; and the discharge of this duty has a direct ten- 

 dency to excite emulation, prompting to further labours 

 that may enlarge the bounds of science. Besides, the 

 history of scientific achievements is the history of the 

 human mind in its noblest exertions, of the human 

 race in its most exalted pursuits. But it is equally 

 clear that the whole value of this, as of every other 

 branch of history, depends upon the diligence with 

 which the facts are examined, the care and even the 

 skill with which their evidence is sifted, the impar- 

 tiality with which judgment is pronounced, and the 

 accuracy with which the record is finally made up. 

 The mere panegyric of eminent men, how elegantly 

 soever it may be composed, must remain wholly worth- 

 less, at the best, and is capable of being mischievous, 

 if it aims at praise without due discrimination, still 

 more if it awards to one man the eulogy which of right 

 belongs to another. Nothing can be more indispensable 

 to the execution of the important task undertaken by 

 the historian of science, than that he should most 

 carefully examine the share which each of its cultiva- 

 tors had in the successive changes it has undergone. 

 The greatest of these have ever felt how valuable such 

 titles are, and have shown the most singular anxiety 

 to compare and to adjust their relative claims. Of these 

 illustrious men I have known two, Black and Watt, 

 and I can safely say that when the question was raised 

 of priority in discovery among either their predecessors 

 or their cotemporaries, they were wont to be particular 

 and minute, even to what seemed superfluous care- 

 fulness, in assigning to each his just share, very far 

 more anxious in making this distribution than they 

 ever showed themselves to secure the admission of 

 their titles in their own case. By a singular injustice 

 of fortune these two philosophers have themselves 



