Abstract
1. The surface tension of an amylamine solution is or is not influenced by the addition of a protein, according to the hydrogen ion concentration of the solution.
2. Only at a H-ion concentration of the solution where a protein exists as anion does the presence of the protein influence the surface activity of the amylamine solution. The change of the surface activity is caused by the combination of protein with amylamine and tends to get the same definite value, whether we manipulate with either lower or higher concentration of the amine.
3. The isoelectric point of protamine lies at pI1 11.0.
I wish to express my indebtedness to Professor S. Kakiuchi for his interest and advice throughout this investigation.
