commercial availability of the reagents from which they are provided and the ease of xsa preparation therewith examples 1a and 2a below illustrate the preferred method of preparing the cationic starch amines sa however novelty of the invention does not lie in the method of preparing the sa it is to be understood that sa in commercial use and those prepared by other methods known and described in the prior art are equivalent to those of examples 1a and 2a for purposes of use within the instant invention the sa are converted to the xsa by reaction with carbon disulfide cs 2 the ordinary procedures and conditions for xanthation of unmodified starch as known in the art are applicable for preparing the instant xsa compositions from sa and are taught for example in lancaster et al 34 xanthation of starch in low concentration pastes 34 i ec prod res develop 5 354 december 1966 which is hereby incorporated by reference examples 1b and 2b below further illustrate the procedure and it is understood that other equivalent methods of xanthation as known in the art could be used the xsa may be stored either as a dispersion or as a dry solid the effectiveness of the instant xsa as paper strengthening agents is a function of.