530 



Prof. W. N. Hartley. 



Society,' vol. 33, p. 1, with the modifications described in the ' Journal 

 of the Chemical Society,' vol. 47, pp. 685 — 757. The absorption-curves 

 have been drawn in the same way as those figured in the latter publi- 

 cation. 



The two bodies, kreatinin and the base from urine, are compounds 

 with a very similar constitution, as is apparent from the two curves 

 accompanying this note. The absorption-bands are not caused by the 

 condensation of the carbon atoms as in aromatic derivatives of ben- 

 zene, but by the condensation of the numerous oxygen and nitrogen 

 atoms, as is the case with uric acid. The absorption-bands, though 

 definite, have no great persistency, but the intensity of the total 

 actinic absorption is great, the band of kreatinin becoming visible 

 when 2 mm. of a solution were examined containing little more than 



1 part of the substance in 1000 of water. With the base from urine 



2 mm. of solution show a band when the same quantity is contained 

 in 5000 of water. 



