28 DB. BASTIAN ON THE 



fiulsh the heating process after the experimental vessel has been 

 hermetically sealed. 



Since the first announcement of my new experiments, and 

 before the publication in detail of my method, two English inves- 

 tigators have attempted to repeat them. Their method of pro- 

 cedure, however, has been inaccurate and probably vitiated by the 

 three causes of error above mentioned as having been pointed 

 out in my original paper now in the possession of the Royal 

 Society ; it was certainly, according to their own statements, 

 vitiated by two of them, as I will now proceed to show. 



After referring to what appeared to bim to be two sources of 

 fallacy in my mode of conducting these experiments (to the men- 

 tion and consideration of which I shall presently return), Dr. 

 William Eoberts * says he determined to repeat them, but taking 

 care to avoid these alleged " defects." He proceeded as fol- 

 lows : — "A flask with a longish neck was charged with an ounce 

 of normal acid urine. The due quantity of liquor potassae requi- 

 site to exactly neutralize this (as ascertained by previous trials) 

 was enclosed in a sealed glass tube drawn to a capillary portion 

 at one end. The tube was then heated in oil up to 280" P., and 

 maintained at that temperature for fifteen minutes. The tube 

 was then introduced into the body of the flask. The neck of the 

 flask was next drawn to a narrow orifice ; then the urine was boiled 

 for Jive minutes, and the orifice sealed in ebullition." Now, having 

 regard to the two passages which I have italicized, it will be seen 

 that Dr. E-oberts's supposed repetition of my experiment was no 

 repetition at all ; that is, he followed the very method most cal- 

 culated to ensure failure, and which even what was said in my 

 published "Abstract " should have warned him against adoptingf. 

 As I shall presently explain, potash, siafficient to render the fluids 

 distinctly alkaline was added ; and this, together with the boiling 

 for five minutes before the vessel was sealed, was doubtless the 

 cause of Dr. Eoberts's failure. 



The same Number of the ' Proceedings of the Eoyal Society ' 

 contains a " Note " by Professor Tyndall, in which he likewise 

 announces the fact that he has failed to reproduce my results. 

 His mode of repeating the experiment was also erroneous, at all 

 events, in those of his trialsinwhiclx he makes any mention of the 



* ' Proceedings of the Eoyal Society,' No. 176, vol. xxv. p. 455. 

 t See 'Proceedings of the Eoyal Society,' vol. x?v. p. 503. 



