

440 Intelligence and Miscellaneous Articles. 



Mr. Flux, apart from a different arrangement of the matter, con- 

 tains nothing which was not taken literally, or in the ordinary 

 sense, from the paper already cited or from another on the same 

 subject*. In one point only does the statement of Mr. Flux differ 

 from mine, without, however, leading to any new results. 



In order to establish the statement I have just made I may be 

 allowed to sketch the separate sections of Mr. Flux's paper, and 

 at the same time refer to the corresponding ones of my own. 

 [For these the reader is referred to the original paper in Wiede- 

 mann's Annalen, No. 8, 1890, p. 738.] 



The author gives the detailed comparison and thus concludes : — 

 In what I have said, where I have gone into all the apparent or 

 actual deviations between Mr. Flux's research and my own, 

 the contention made at the beginning of this article will appear 

 abundantly justified. Apart from the alteration of a proof, the 

 research of Mr. Flux, both as regards results and their establish- 

 ment, is nothing further than a repetition of what I had already 

 carried out in my two researches or what Herr G-umlich had done 

 in his paper which is connected therewith. 



In conclusion, it may be mentioned that the confirmation which 

 my theoretical investigations had met with in the careful observa- 

 tions of Prof. Sohncke is mentioned by Mr. Flux, but dismissed in 

 less than two lines. — Abstract of communication from the Author. 



FLUORESCENT VAPOURS. BY F. WIEDEMANN. 



Professors Ramsay and Toungf had described an experiment 

 according to which solutions of eosine fluoresce above the critical 

 temperature, without, however, as they themselves state, consider- 

 ing it to be strictly proved. Independently of them I made at the 

 same time an analogous experiment which, however, gives perfectly 

 certain results, and which I here communicate from the Proceed- 

 ings of the Societas Physico-medica at Erlangen for the year 1888. 



Experiments with liquids which were sealed in capillary tubes 

 gave a very distinct fluorescence above the critical temperature for 

 solutions of eosine and Magdala red in alcohol. That it is not 

 diffused light with which we have to deal is shown if we use as 

 source of light that which has passed through ainmomacal copper 

 sulphate, which contains no yellow or red rays. The fluorescent 

 light contains these rays ; this is distinctly seen when a lens is 

 used, the cone of light is distinctly seen continued in the vapour, 

 and is especially beautiful with Magdala red. Experiments with 

 saffranine gave no results, as it is decomposed. "With Magdala 

 red there is also a feeble decrease in coloration after heating. — 

 Wiedemann's Annalen, No. 10, 1890. 



* A. Wangerin, Wied. Ann. xx. pp. 177 et seqq. (1883). 

 t Chemical N T ews, vol. liii. p. 205 (1886). 



