80 



Messrs, Jones and Dupre on a Substance j [Apr. 12, 



The solution of egg-albumen, exposed to the ah-, gradually after some 

 days showed a strong green fluorescence, which, like esculine, disappeared 

 on the addition of an acid, but was not destroyed by alkalies. The fluo- 

 rescence gradually disappeared when the albumen began to putrefy. 



Part II. 



On the Increase of Fluorescence in the Textures of Animals and Man after 

 Quinine had been taken. 



Having proved that in all the different textures of an animal a natural 

 alkaloid fluorescent substance was present when no quinine had been taken, 

 and as no means could be found for separating the natural fluorescent 

 substance from the quinine when it passed into the textures, it became 

 necessary to make our analyses quantitative instead of qualitative. 



For this purpose it was necessary to determine, by means of standard 

 solutions of quinine, what was the greatest amount of naturally fluorescent 

 substance that usually occurred and could be extracted from the tissues. 

 Deducting this from the amount of fluorescence that could be extracted 

 after quinine was given, we were enabled to measure the rapidity of pas- 

 sage of the quinine into or out of the tissues, the animals being destroyed 

 at different periods after different quantities of sulphate of quinine had 

 been taken. 



So also by determining the amount of natural fluorescent substance in the 

 textures, lenses, and urine of man before quinine was taken, and deducting 

 this from the amount obtained after quinine was taken, we were enabled 

 to show that quinine does pass into the textures and lenses, and how 

 quickly it appeared in the urine and reached its maximum and began to 

 disappear and entirely vanished. 



First. Examinations of different textures of guineapigs when no quinine 

 was taken, and comparison of the amount of natural fluorescent substance 

 with standard solutions of sulphate of quinine. The amount of the dif- 

 ferent parts examined was as nearly as possible always the same : — 



1 . A guineapig that had taken no quinine was killed ; the extract of the 

 brain and nerves only was measured. The fluorescence of the nerves was 

 very feeble, and about equal to one-twentieth of a grain of sulphate of 

 quinine in a litre of water. The extract of the brain was exceedingly feeble, 

 and it was less than one-thirtieth of a grain of sulphate of quinine in a litre 

 of water. 



2. In another guineapig the lenses and the nerves were dried, and boiled 

 three times with dilute sulphuric acid. The acid solution was rendered 

 alkaline by caustic potass, and it was then shaken up with ether three 

 times. The ethereal solution was evaporated, and the residue dissolved in 

 dilute sulphuric acid. The acid solution was made up to twenty-five 

 minims. The solutions of the lenses and of the nerves showed some 

 fluorescence. 



These acid solutions were now again rendered alkaline and were shaken 

 up with ether, and the ethereal solution was evaporated and the residue 



