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



Nerves fluoresced a little more than one 64tli of a grain of 



quinine to a litre =1*6 



Liver fluoresced one 64th of a grain of quinine to a litre. ... =1*6 

 Muscle fluoresced one 64th of a grain of quinine to a litre . . =1*6 

 Spleen fluoresced a little less than one 32nd of a grain of qui- 

 nine to a litre =3*1 



Lungs fluoresced one 128th to one 64th of a grain of quinine 



to a litre =0*8 to 1'6 



Fourthly. On the increase of fluorescent substance in the human lens 

 after difl^erent quantities of sulphate of quinine had been taken at diff'erent 

 periods before the operation for cataract (for the means of making these 

 experiments we are indebted to the great kindness of Mr. Bowman) ; — 



The fluorescence of the human lens without cataract was about equal to 

 one 64th of a grain of quinine in a litre of water ; grs. per 100 litres. 



That is, natural fluorescence about =1*6 



Sulphate of quinine was given for many days previous to the 

 extraction of a cataract. After the operation the fluores- 

 cence was found to be less than one 16 th and more than 



one 32nd of a grain of quinine to a litre of water =6*2 to 3' 1 



In four patients, aged respectively 75, 60, 60, and 72 : — 

 the lens removed 1 hour after 5 grains of quinine, fluorescence =1*6 

 >J li }y a =1*6 



2 „ „ =1-6 



H » „ =2-1 to 1-6 



Fifthly. On the rate of increase of fluorescent substance in the urine 

 after quinine was taken, or on the rapidity of the passage of quinine, when 

 taken by the stomach, into and out of the urine of man : — > 



A healthy man breakfasted at 8.30 a.m. ; at 12 he emptied the bladder, 

 and took four grains of sulphate of quinine in solution. The fluorescence 

 of the urine at diff'erent periods after the quinine was taken was examined 

 by rendering it alkaline with caustic potash and shaking it up three times 

 with its own bulk of ether. Half an ounce of urine was taken for each 

 examination. 



Urine passed at gr. of quinine, water. 



12 (just before taking the quinine), fluorescence=Y|-g- to -^^ to 1 litre. 



12.10, fluorescence = „ 



12.20 „ = itoi „ 



12.30 „ = itoj „ 



1 3> = I to J 



2 » = itol 



4 - = 5 to „ 



« = i 



24 hours after quinine, fluorescence =-i^^ li^-tle less. 



48 „ ^ . = A> little more. 



^2 « » about jiy- „ 



