124 



Scientific Proceedings (58). 



3. If our impression that the nucleus of the growing cell 

 is actually stained prove correct, the use of stains in the plasma in 

 which tissue is grown should certainly facilitate the study of 

 nuclear growth. 



4. Certain observations made last year in this laboratory (too 

 few to serve as more than a suggestion) seem to indicate that 

 another dye (methylene blue) acted as a stimulant to the growth 

 of connective tissue. This lead also should be followed out and 

 the effect of all possible stains studied in the hope of discovering 

 dyes which will have a sharp selective action on growing tissue. 



5. The growth of animal cells in a strength of dye much more 

 than sufficient to kill many pathogenic organisms lends encourage- 

 ment to the efforts now being made in this laboratory to apply the 

 observations on the bactericidal effect of gentian violet and allied 

 stains to the treatment of disease. 



76 (893) 



On the hexosamine of chondroitin sulphuric acid. 



By P. A. Levene and F. B. La Forge. 



[From the Laboratories of the Rockefeller Institute for Medical Re- 

 search, New York.] 



In a previous communication 1 the writers reached the conclu- 

 sion that the nitrogenous component of chondroitin sulphuric acid 

 was glucosamine. The conclusion was based on the analytical 

 data of the hydrochloride of the amino sugar, and on the magnitude 

 of its optical rotation. 



However, recently it was discovered that the optical activity 

 of the amino sugar differed considerably from that of glucosamine, 

 if measured under very definite conditions. The conditions re- 

 quired are the following: low temperature of the solution, com- 

 paratively high concentration of the sugar solution, and measuring 

 the initial rotation immediately after the solution of the sugar is 

 accomplished. Under such conditions it was found that the speci- 

 fic rotation of the amino sugar of the chondroitin sulphuric acid 

 was about 25 per cent, higher than that of glucosamine. Both 



1 Jour. Biol. Chem., XV, p. 155, 1913. 



