191 3] Walter H. Eddy 429 



bring out the points at issue, which may be briefly summarized as 

 f ollows : 



Lilien feld first advanced the proposition that a water extract of 

 thymus glands contains nucleohiston, precipitable by acetic acid. 

 From his study of this substance he suggested a Constitution that is 

 indicated by the appended tabular sequence of decomposition 



products : 



Thymus nucleohiston 



I ^1 . 



Histon Leuconuclein 



I I . 



Protein Nuclein 



I I 



Protein Nucleic Acid 



Malengrau (20) repeated Lilienfeld's work and claimed that the 

 latter's precipitate was a mixture of at least two substances. 

 Malengrau called these " nucleoalbumins A and B." He obtalned 

 histon from each. Bang (3) entered the discussion in 1900 and, 

 while agreeing with Malengrau that Lilienfeld's nucleohiston was a 

 mixture, maintained that a water extract of thymus contained at 

 least three substances : Histon, nucleic acid, and a nucleoprotein 

 free from histon. He interpreted Lilienfeld's results as follows: 



Acetic acid plus water extract of thymus yields a precipitate which 

 is a mixture of histon nucleate and nucleoprotein (Lilienfeld's 

 nucleohiston). This precipitate, in 0.8 per cent. hydrochloric acid 

 Solution, yields histon hydrochlorid plus a mixture of nucleic acid 

 and nucleoprotein (Lilienfeld's leuconuclein). In 1901 Huiskamp 

 (10) stated his belief that Lilienfeld's nucleohiston is a mixture of 

 nucleoprotein and nucleohiston. The latter he separated by adding 

 calcium chlorid to an extract of thymus, to a strength of 0.2 per 

 cent., obtaining a precipitate of calcium nucleohiston and a Solution 

 of nucleoprotein. The former yielded histon hydrochlorid with 

 extraction in 0.8 per cent. hydrochloric acid Solution and, according 

 to Huiskamp, a nuclein but not a nucleic acid as was maintained 

 by Bang. 



In 1903-4 Bang (6) reported an extensive study of the whole 

 problem. He summarized the results to this point as follows: 

 Huiskamp claimed that thymus contains and yields to water, a 



