218 Dr. Thndiclium on the Colouring -matter of the Urine. [Dec. 12/ 



He has prepared twelve specimens by various processes, and analyzed 

 many of them, as well as a great number of their compounds, with various 

 metals. These preparations are marked respectively as in the following 

 list :— 



Prize Essay preparations. Compounds. 

 By boiling with SO^ :— 

 A.I. From fresh urine. Elementary analyses. Neutral. Ba salt (Ur^ Ba), 



Zn salt (Ur. Zn,), Bb salt {Vv^ Bb,). 

 A. II. From fresh urine. Ag salt (Ur Ag), Ba salt (Ur^ ^^s)* 

 By addition of 11^ SO^, no boiling : — 



A. III. From putrid urine. Ag salt (Ur Ag), Ba salt (Ur^ Bag), €a salt 



(Ur,€a3). 



Preparations made for the present research. 



By boiling with H, SO, :— 



B. I. ' 



B. II. Two elementary analyses. 



B. III. 



Before boiling with II^ SO, : — 



C. I. " 

 After boiling : — 



C. II. Six elementary analyses. 

 Before boiling : — 



D. I. Two N determinations. N = 13-58 per cent. Agsalt (Ur^ Ag,), Ca 



salt (Ur3 €a) and (Ur, Q^,), Zinc-salt (Urg Zn). 

 After boiling with SO, : — 

 D. II. 

 D. III. 



D. lY. Two N determinations. N= 12'40 per cent. Ag salt {TJr^ Ag.), Ba 

 salt (Ur, Ba) and Zinc-salt (Ur, Zn) . 



Synopsis of TJromelanates obtained with the foregoing preparations. 

 Silver-salts. 



Preparation. Ur ^ Ag. Ag. four.d. 



(A. II.), (A. III.) . 1 1 13-38 per cent. 



(D. I.) 2-^3 18-57 



(D. IV.) 3^5 19-77 



Barium-salts. 



Ur -h- Ea. Sa found. 



(D. lY.) 5 -^ 2 7-20 per cent. 



(A. I.), (D. lY.).. 2 ] 8-34 



(A. IL), (A. III.). . 4-^3 13-28 



