Prof. Tyndall on the History of Calorescence, 221 



Sections at Newcastle, I did not know that you had brought the 

 subject forward there. Professor Stokes, however, informed me that 

 you were engaged on the question, and I had similar information 

 from the ' Saturday Review.' 



" There is certainly a most singular coincidence in the thoughts 

 which have passed through both our minds on some of the points in 

 question. As to the possibility of converting the Herschellic into 

 the Newtonic rays I do not entertain a doubt ; and indeed the piece 

 of work which I had set before me for attack on my return from this 

 place was a series of experiments on this very subject. 



" I have devised a very perfect means of sifting the Herschellic 

 from the Newtonic rays, and with the latter alone I have strong 

 hopes of being able to produce incandescence. But you have entered 

 this field before me, and although the question lies directly in the way 

 of my own inquiries, I should like to do in the matter what would be 

 most pleasing to you. I shall be in town on Saturday next, at the 

 Royal Institution at noon ; could you not look in upon me there ? 



" Yours very sincerely, 



" John Tyndall." 



In the December Number of the Philosophical Magazine, 

 p. 559, Dr. Akin employs the following language with refer- 

 ence to this letter : — " I must be allowed to express here a 

 doubt whether Sir Humphry Davy, for example, or any other 

 predecessor of Professor Tyndall at the Royal Institution, hav- 

 ing read in a public print that two persons were engaged in 

 making researches on a certain subject with the aid and sanction 

 of the British Association, would have chosen ( that very subject' 

 for ' attack ' some little time after. - " I, on the other hand, may 

 be permitted to express the assured conviction that Sir Humphry 

 Davy would never have given Dr. Akin the chance of garbling 

 his language as he has here garbled mine. The reader will com- 

 pare the words " attack " and " that very subject," as held in the 

 claws of his inverted commas, with the same words as they occur 

 in my note, and draw his own conclusions as to the temper of the 

 quoter. 



The fundamental error of Dr. Akin consists in his interpreting 

 the attitude assumed by me in the foregoing note, as one which, 

 under the circumstances, he had a right to expect. What most 

 men would have regarded as an act of free courtesy on my part, 

 Dr. Akin interprets as an acknowledgment of his inordinate 

 claims. He does not seem to understand why, of my own free 

 will, I conceded to him a position which I should unquestionably 

 have refused had it been demanded as a right. As I have 

 already stated to him, " there was nothing in the circumstances 

 of the case to prevent me from working at the subject, restricting 

 myself to a due reference to his labours." Had I been aware that 

 my note had excited his " astonishment," I should have acted 



