234 Dr. C. A. MacMunn. Researches into the [Dec. 16 r 



There appeals to be one point of difference between normal urobilin 

 and choletelin and the pigment obtained from haematoin : that is, 

 that while chloride of zinc produces a narrow band nearer the red 

 with an alcoholic solution of normal urobilin, it does not produce that 

 band with the latter pigments until they have been slightly reduced 

 with sodium amalgam ; this would show that some change (reduction) 

 has taken place in the normal urinary pigment during its passage 

 from the blood into the urine. 



EXPLANATION OF CHARTS. 



The accompanying charts were mapped from the microspectroscope provided with 

 an accurately divided photographed scale, and' the scale at the top of each chart is- 

 that of the instrument. Accompanying these charts is a table giving the value of 

 each division of the scale in wave-lengths. I have adopted this plan in order to 

 avoid having two scales adapted to the charts ; and a scale of wave-lengths would 

 not be accurate adapted to maps drawn this size. 



Chaet I. 



Spectrum 1. 



Solar spectrum. 



55 



2. 



Normal urobilin in alcohol. 



55 



3. 



The same treated with chloride of zinc. 



55 



4. 



Action of sodium amalgam on brown-yellow normal urobilin, and of 







caustic soda on brown urobilin. 



55 



5. 



Acidulated alcoholic extract of urohaematin from urine of rheumatism ; 







deep layer. 



55 



6. 



Chloroformic solution of the same pigment. 



55 



7. 



Alcoholic solution of ditto. 



55 



8. 



Shallow depth of the same. 



!5 



9. 



Deep layer of alcoholic solution (7) treated with caustic soda or 







ammonia. 





10. 



The same, shallow depth. 



55 



11. 



Urohsematin in alcohol, treated with hydrochloric acid. 



55 



12. 



The same treated with sulphuric acid. 





13. 



The same with sodium amalgam. 



55 



14. 



The pigment (acted on by amalgam) with hydrochloric acid. 



55 



15. 



Acidulated alcohol extract of pigment got from the urine of a case of 







pleurisy ; deep layer. 





16. 



Ditto, shallow layer. 



„ 17 and 18. The alcoholic solution of this pigment treated with caustic soda, 

 in deep and shallow layers. 



Chaet II. 



Spectrum 1. Solar spectrum. 



„ 2. Alcoholic extract human gall-stone. 



,, 3. The same treated with caustic soda or ammonia. 



„ 4. Chloroformic solution of bilirubin. 



„ 5, 6, 7, 8, 9, 10. Action of chlorine on this solution. 



, 11. The pigment of stage represented in sp. 10 treated with sodium 

 amalgam and afterwards hydrochloric acid. 



