144 Dr. Akin's further Statements concerning 



far from conclusive ; or else I should not have written privately 

 on the subject, as it would have been too late to carry out our 

 agreement. Several more letters passed between us, the result 

 of which was that Prof. Tyndall volunteered to bind himself not 

 to make known publicly or privately any experiments on ray- 

 transmutation till November 1865 ** When I wrote in reply that, 

 being anxious to see the matter upon which I had been working 

 proved, and not having any hope of being able to pursue the 

 subject myself any further, in the interest of science I would not 

 hold him to the engagement to which he had volunteered to bind 

 himself, Prof. Tyndall answered that, to his regret, he could not 

 accept the release I had offered him, his simple duty appearing 

 to him to be strictly to adhere to the engagement to which he had 

 voluntarily pledged himself. Notwithstanding this, Prof. Tyndall 

 has seized the very first opportunity that offered itself to him to 

 publish, some eleven months in advance, those very experiments 

 which, he had asserted, he could not with any degree of satis- 

 faction to himself publish before November 1865, as there were 

 things more important in his estimation than the mere claims of 

 science. 



3. I now turn to reply to Prof. TyndalPs paper more in de- 

 tail. In doing so, however, I shall not take any more notice of 

 his personal animadversions than will be absolutely necessary for 

 the vindication of my person from the insinuations levelled 

 against me. 



My tf Note on Ray-Transmutation," published in the Supple- 

 mentary Number of the Philosophical Magazine for December 

 1864, though not exclusively, was principally intended to point out 

 a capital defect in Prof. TyndalFs published reasoning regarding 

 the origin of lime-light, &c. Prof. Tyndall does not deny that there 

 is a "missing link" in his argument ; but, adopting a well-known 

 forensic device, he turns round upon me, and charges me with 

 having committed an even greater error. I had spoken, he says, 

 of the " paucity of rays of high refrangibility in a hydrogen- 

 flame." Now, Prof. Tyndall quotes passages from the writings 

 of Prof. Stokes, which appear to prove the fact to be the reverse 

 of my assumption. In doing so, however, Prof. Tyndall evidently 

 forgets that, the richer a hydrogen-flame is in invisible Ritteric 

 rays, the more egregious is the oversight he committed in leaving, 

 in his own reasonings concerning the phenomena of lime-light, 

 &c, the Ritteric rays altogether out of consideration. In the 

 paper published in the Reports of the British Association for 

 1863, I certainly called the oxyhydrogen "poor" in Ritteric 

 rays, because, according to Dr. Miller's observations, the pho- 



* Prof. Tyndall added, however, that he would hold himself at liberty 

 to repeat and develope his experiments " on combustion" by invisible rays. 



