The composition of stratospheric positive ions have been measured over an extended altitude range (24-42 km) using balloon-borne mass spectrometers. It was found that proton hydrate and nonproton hydrate ion, mostly H+(X)L(H2O)M coexist throughout this region. The fractional abundance of non proton hydrate ions decreases somewhat with increasing height. Implications for the abundance of X, which probably is CH3CN are discussed.