Cystinuria 



MAX KAHN 



NEW YORK 



JACOB ROSENBLOOM 



PITTSBURGH 



Of the sulphur in the protein molecule, our knowledge is not very 

 extensive. Most writers have expended their energies on the cystin- 

 sulphur fraction, and some have gone so far as to say that all the sulphur 

 in protein is in the cystin combination. That comparatively little atten- 

 tion has been paid to this substance is shown by the fact that there elapsed 

 three-quarters of a century between its discovery in a cystin calculus and 

 its exact organic analysis. 



In 1810 Wollaston(6), in a paper entitled "On Cystin Oxid, a New 

 Species of Urinary Calculus," reported before the Royal Society of Lon- 

 don the discovery of cystin, which he called cystic oxid, and which the 

 Germans translated into Blasenoxyd, or bladder oxid. 



Berzelius suggested that the name cystic oxid be changed to cystin. 

 In 1838, Civiale wrote that, although this change corrected an error in 

 chemistry, it perpetuated an error of physiology, for cystin is excreted 

 by the kidneys and does not have its origin in the bladder (Garrod). 



Cystin forms six-sided leaves or rhombic crystals. It is insoluble in 

 water and alcohol. It is soluble in concentrated mineral acids. It is 

 easily soluble in alkalies from which it can be precipitated only by or- 

 ganic acids, but not by mineral acids (Beilstein). In 1882 Mauthner 

 called attention to the fact that cystin was levorotatory. Kulz(fr), in a very 

 short notice, in the same year stated that the levorotation of cystin was 

 140. Mauthner made more careful determinations and found that in 

 solution in hydrochloric acid (11.2$?) (a D = -205.9. 



Prout was the first to analyze cystin, but he overlooked the presence 

 of sulphur. This analysis was confirmed by Pelouze. The credit for the 

 discovery of sulphur in cystin is due to Boudrimont and Malaguti(a) (6), 

 but they did not make a quantitative analysis. This was done by Thaulow 

 in 1838. If we make a comparison of the figures obtained in the analysis 

 of cystin by some of the older chemists we must observe how very close to 

 the truth some of them were : 



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