SKETCH OF PROFESSOR TYNDALL. 107 



acoustics from the same general point of view, and deals with atmos- 

 pheric wave-motion in connection with the properties and constitution 

 of the various forms of matter. The researches on the formation of 

 clouds in tubes filled with various gases and vapors under the influence 

 of the electric beam, and the resulting inquiry into the subject of atmos- 

 pheric dust, were but parts of the same comprehensive investigation 

 into molecular conditions and transformations. 



Prof. Tyndall has won his scientific reputation as an explorer in the 

 field of experimental physics, but he has also a commanding position as 

 a philosophic thinker. The questions that can be resolved by experiment 

 lead on to questions that can be resolved only by reason. Philosophy 

 is old and easy, and the human mind has overflowed with it from the 

 beginning ; but philosophy grounded in the knowledge and method of 

 science is as yet. rare, though it is nevertheless a glorious reality. 

 If scientific thinking is the result of an apprenticeship of centuries in 

 the management of the intellect, and if the mind's scientific action is 

 its most perfect action, then must scientific men, as the world goes on, 

 be more and more trusted in their opinions. Such is undoubtedly 

 the present tendency. This is shown generally in the increasing rec- 

 ognition of the scientific school of philosophy, and it is specially exem- 

 plified, in the present case, by the interest that is taken in whatever 

 Prof. Tyndall has to say to the public, and whatever the subject on 

 which, he speaks. This high scientific position gives acknowledged 

 weight and force to his views. But Prof. TyndalPs philosophic cast 

 of mind not only attracts him to the deeper questions of the time, but 

 his courageous temper leads him to deal with them candidly and fear- 

 lessly. First of all, a devotee of science and a lover of truth, he gives 

 to these his sole allegiance. An independent and intrepid inquirer, 

 tolerant of honest error, but contemptuous of that timid and calculat- 

 ing spirit which would protect men's prejudices from the light of 

 investigation, he is without fear in the free and manly expressions 

 of his opinions. That these should often contravene prevailing beliefs 

 is inevitable. A Protestant by hereditary instinct and in his blood, 

 and long drilled in the severities of scientific logic, it is impossible 

 that he should not find much in current opinion to excite continued 

 and trenchant protest. 



Allied with this cherished freedom of thought and utterance, there 

 is in Prof. TyndalPs character an intense love of justice, and a passion 

 for fair dealing that is quite chivalric. This temper has been displayed 

 on various occasions, but in none more conspicuously than in his generous 

 defence of the German physicist, Mayer, whose scientific claims he con- 

 sidered to be depreciated by English scientists. Mayer's had been a 

 hard fate. An undoubted pioneer in establishing the important doc- 

 trine of the correlation of forces, working out its several lines of proof 

 with marvellous sagacity and an amount of exhausting labor that re- 

 sulted in mental derangement, and with little sympathetic recognition 



