relative to Black, Watt, and Cavendish. 517 



of the demesne of experimental philosophy with more delibe- 

 ration than your leisure seems usually to allow you, but even 

 ventured on searching some of the inner chambers of the art 

 of experiment, I must appeal to you, not in the style of arch 

 solemnity with which your " illustrious colleague " addressed 

 you in the chamber of the Institute, as having weighed the 

 evidence in the case of Watt versus Cavendish — " Avec le 

 scrupule en quelque sorte judiciaire qu'on pouvoit attendre de 

 l'ancien Lord Chancellor dela Grande Bretagne*," — but I ap- 

 peal to you, as ever you have learnt the laws of evidence from 

 the only Chancellor of England who is of authority in philo- 

 sophical questions, as ever you have listened to, and compre- 

 hended, that pupil of Bacon and Newton, the beauty of whose 

 lectures you have so vividly described, — to take some shame 

 to yourself, for having perused, by your own confession, the 

 notes of Cavendish, without perceiving that all which I have 

 said of the experiments of Black, as being so connected as 

 clearly to manifest the whole train of the experimenter's 

 thoughts, is still more clearly true of these. 



You know what the problem was, on the investigation of 

 which Cavendish was intent when he made the discovery in 

 question. You know his aim to have been to find out what 

 was become of " the air lost " in the combustion of hydrogen 

 with common air. And what were the preliminary trials by 

 which he searched for the lost gases ? He tried — 1. whether 

 they were "changed" into carbonic acid ; — 2. whether they were 

 " changed" into nitric acid; — 3. whether they were changed 



* Annuaire, 1839, Note, p. 361. Lord Brougham, out of court, deals I 

 fear as hastily with literature as with science ; and there also sometimes 

 makes the facts on which he reasons. Thus he criticises as "unintelligible" 

 the condensed sense of that well-known line, in which Johnson, in his imi- 

 tation of the Tenth Satire of Juvenal, speaks of '" patience" as " sovereign 

 o'er transmuted ill:" but he first makes it unintelligible, by substituting 

 from his own poetical mint — " nature," where Johnson had written "pa- 

 tience." (Life of Johuson, p. 76.) Again, he animadverts severely on John- 

 son for " roaring out, 'No, Sir ! ' in the presence of Hume, on being asked 

 by a common friend to let him present the Historian to the Moralist" 

 (Life of Hume, p. 223) ; and he adds, "above all we have a right to com- 

 plain that the associate of Savage, the companion of his debauches, should 

 have presumed to insult men of such pure minds as David Hume and Adam 

 Smith, rudely refusing to bear them company, but for an instant." (Life of 

 Johnson, p. 22.) It is curious to compare this with Johnson's own account : 

 *' I was but once in Hume's company; and then his only attempt at merri- 

 ment consisted in his display of a drawing too indecently gross to have de- 

 lighted even in a brothel." (Hawkins.) The real man from whom Johnson 

 turned on his heel, was one who added to the moral purity of the school 

 of Voltaire the garb of an ecclesiastic, — a circumstance which perhaps may 

 abate something of Lord Brougham's indignation at the ill-manners of 

 Johnson. 



